<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE article  PUBLIC "-//NLM//DTD Journal Publishing DTD v3.0 20080202//EN" "http://dtd.nlm.nih.gov/publishing/3.0/journalpublishing3.dtd"><article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" dtd-version="3.0" xml:lang="en" article-type="research article"><front><journal-meta><journal-id journal-id-type="publisher-id">JCT</journal-id><journal-title-group><journal-title>Journal of Cancer Therapy</journal-title></journal-title-group><issn pub-type="epub">2151-1934</issn><publisher><publisher-name>Scientific Research Publishing</publisher-name></publisher></journal-meta><article-meta><article-id pub-id-type="doi">10.4236/jct.2017.82011</article-id><article-id pub-id-type="publisher-id">JCT-74050</article-id><article-categories><subj-group subj-group-type="heading"><subject>Articles</subject></subj-group><subj-group subj-group-type="Discipline-v2"><subject>Medicine&amp;Healthcare</subject></subj-group></article-categories><title-group><article-title>
 
 
  Trace Element Levels in Prostate Gland as Carcinoma’s Markers
 
</article-title></title-group><contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Vladimir</surname><given-names>Zaichick</given-names></name><xref ref-type="aff" rid="aff1"><sup>1</sup></xref><xref ref-type="corresp" rid="cor1"><sup>*</sup></xref></contrib><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Sofia</surname><given-names>Zaichick</given-names></name><xref ref-type="aff" rid="aff2"><sup>2</sup></xref></contrib></contrib-group><aff id="aff2"><addr-line>Laboratory of Dr. G.C. Piso, Northwestern University, Feinberg School of Medicine, Chicago, IL, USA</addr-line></aff><aff id="aff1"><addr-line>Radionuclide Diagnostics Department, Medical Radiological Research Centre, Obninsk, Russia</addr-line></aff><author-notes><corresp id="cor1">* E-mail:<email>vezai@obninsk.com(VZ)</email>;</corresp></author-notes><pub-date pub-type="epub"><day>06</day><month>02</month><year>2017</year></pub-date><volume>08</volume><issue>02</issue><fpage>131</fpage><lpage>145</lpage><history><date date-type="received"><day>January</day>	<month>9,</month>	<year>2017</year></date><date date-type="rev-recd"><day>Accepted:</day>	<month>February</month>	<year>7,</year>	</date><date date-type="accepted"><day>February</day>	<month>10,</month>	<year>2017</year></date></history><permissions><copyright-statement>&#169; Copyright  2014 by authors and Scientific Research Publishing Inc. </copyright-statement><copyright-year>2014</copyright-year><license><license-p>This work is licensed under the Creative Commons Attribution International License (CC BY). http://creativecommons.org/licenses/by/4.0/</license-p></license></permissions><abstract><p>
 
 
  Objectives: The aim of this study was to evaluate the changes in the prostatic levels of trace elements in the malignant human prostate. 
  Methods: Contents of 43 trace elements in normal (N, n = 37), benign hypertrophic (BPH, n = 32) and cancerous (PCa, n = 60) prostate were investigated. Measurements were performed using instrumental neutron activation analysis and inductively coupled plasma mass spectrometry. 
  Results: The mass fractions of all trace elements with the exception of La, Nb, and Yb show significant variations in cancerous prostate when compared with normal and BPH prostate. The contents of Co, Hg, Rb, Sc, Se, and Zn were significantly lower and those of Ag, Al, Au, B, Be, Bi, Br, Ce, Cr, Cs, Dy, Er, Gd, Ho, Li, Mn, Mo, Nd, Ni, Pb, Pr, Sb, Sm, Sn, Tb, Th, Ti, Tl, Tm, U, Y, Yb, and Zr were significantly higher in PCa than in BPH tissues. When trace elements of cancerous prostate were compared with those in normal prostatic parenchyma, contents of Cd, Rb, Sc, Se, and Zn were significantly lower and Ag, Al, Au, B, Be, Bi, Br, Ce, Cr, Dy, Er, Fe, Gd, Hg, Ho, Li, Mn, Nd, Ni, Pr, Sb, Sm, Sn, Tb, Th, Tl, Y, and Zr were significantly higher. 
  Conclusion: The Ag, Al, B, Br, Li, Mn, Ni, and Zn mass fraction in a needle-biopsy core can be used as the informative indicators for distinguishing malignant from benign prostate. Sensitivity, specificity, and accuracy of these tests were in range 72% - 100%, 66% - 100%, and 74% - 98%, respectively.
 
</p></abstract><kwd-group><kwd>Trace Elements</kwd><kwd> Prostate</kwd><kwd> Benign Prostatic Hypertrophy</kwd><kwd> Prostatic Carcinoma</kwd><kwd> Neutron Activation Analysis</kwd><kwd> Inductively Coupled Plasma Masas Spectrometry</kwd></kwd-group></article-meta></front><body><sec id="s1"><title>1. Introduction</title><p>The prostate gland may be a source of many health problems in men past middle age, such as the most common benign prostatic hyperplasia (BPH), and prostatic carcinoma (PCa). BPH is a noncancerous enlargement of the prostate gland leading to obstruction of the urethra and can significantly impair quality of life. The prevalence of histological BPH is found in approximately 50% - 60% of males age 40 - 50, in over 70% at 60 years old and in greater than 90% of men over 70 [<xref ref-type="bibr" rid="scirp.74050-ref1">1</xref>] [<xref ref-type="bibr" rid="scirp.74050-ref2">2</xref>] . In many Western industrialized countries, including North America, PCa is the most frequently diagnosed form of noncutaneous malignancy in males. Except for lung cancer, PCa is the leading cause of death from cancer [<xref ref-type="bibr" rid="scirp.74050-ref3">3</xref>] - [<xref ref-type="bibr" rid="scirp.74050-ref8">8</xref>] . Although the etiology of BPH and PCa is unknown, some trace elements have been highlighted in the literature in relation to the development of these prostate diseases [<xref ref-type="bibr" rid="scirp.74050-ref9">9</xref>] - [<xref ref-type="bibr" rid="scirp.74050-ref29">29</xref>] .</p><p>Trace elements have essential physiological functions such as maintenance and regulation of cell function and signalling, gene regulation, activation or inhibition of enzymatic reactions, neurotransmission, and regulation of membrane function. Essential or toxic (mutagenic, carcinogenic) properties of trace elements depend on tissue-specific need or tolerance, respectively [<xref ref-type="bibr" rid="scirp.74050-ref30">30</xref>] . Excessive accumulation, deficiency or an imbalance of the trace elements may disturb the cell functions and may result in cellular degeneration, death and malignant transformation [<xref ref-type="bibr" rid="scirp.74050-ref30">30</xref>] .</p><p>In earlier reported studies [<xref ref-type="bibr" rid="scirp.74050-ref31">31</xref>] - [<xref ref-type="bibr" rid="scirp.74050-ref64">64</xref>] significant changes of some trace element contents in hyperplastic and cancerous prostate in comparison with those in the normal prostatic tissue were observed. Moreover, a significant informative value of Zn content as a tumor marker for PCa diagnostics was shown by us [<xref ref-type="bibr" rid="scirp.74050-ref65">65</xref>] [<xref ref-type="bibr" rid="scirp.74050-ref66">66</xref>] . Hence some other trace elements besides Zn probably can be used as tumor markers for distinguishing between benign and malignant prostate.</p><p>Currently a number of methods were applied for the measurement of chemical elements contents in samples of human tissue. Among these methods, the instrumental neutron activation analysis with high resolution spectrometry of long-lived radionuclides (INAA-LLR) is non-destructive and one of the most sensitive techniques. It allows to measure the trace element contents in few milligrams tissue without any treatment of sample. Analytical studies of the Ag, Co, Cr, Fe, Hg, Sb, Sc, Se, and Zn contents in normal, BPH and PCa tissue were done by us using INAA-LLR [<xref ref-type="bibr" rid="scirp.74050-ref15">15</xref>] [<xref ref-type="bibr" rid="scirp.74050-ref20">20</xref>] [<xref ref-type="bibr" rid="scirp.74050-ref28">28</xref>] [<xref ref-type="bibr" rid="scirp.74050-ref60">60</xref>] [<xref ref-type="bibr" rid="scirp.74050-ref62">62</xref>] . Nondestructive method of analysis avoids the possibility of changing the content of trace elements in the studied samples [<xref ref-type="bibr" rid="scirp.74050-ref67">67</xref>] [<xref ref-type="bibr" rid="scirp.74050-ref68">68</xref>] [<xref ref-type="bibr" rid="scirp.74050-ref69">69</xref>] [<xref ref-type="bibr" rid="scirp.74050-ref70">70</xref>] , which allows for the first time to obtain reliable results. In particular, it was shown that the average mass fraction of Co, Cr, Hg, Sb, and Se in BPH was higher than normal levels [<xref ref-type="bibr" rid="scirp.74050-ref66">66</xref>] . In PCa tissues the mean values of Ag, Cr, Fe, Hg, and Sb were higher while those of Co, Rb, Sc, and Zn were lower than in healthy prostatic tissue [<xref ref-type="bibr" rid="scirp.74050-ref60">60</xref>] [<xref ref-type="bibr" rid="scirp.74050-ref66">66</xref>] . Obtained results formed the basis for a new method for differential diagnosis of BPH and PCa, the essence of which was to determine the content of trace elements in the material of needle biopsy of prostate indurated site.</p><p>It is obvious that the most effective methods will be non-destructive analytical methods because they involve a minimal treatment of sample since the chances of significant loss or contamination would be decreased. However, the INAA- LLR allow only to determine the mean mass fractions of 9 - 10 trace elements in the samples of normal and cancerous prostate glands [<xref ref-type="bibr" rid="scirp.74050-ref15">15</xref>] [<xref ref-type="bibr" rid="scirp.74050-ref20">20</xref>] [<xref ref-type="bibr" rid="scirp.74050-ref28">28</xref>] [<xref ref-type="bibr" rid="scirp.74050-ref60">60</xref>] [<xref ref-type="bibr" rid="scirp.74050-ref66">66</xref>] . The inductively coupled plasma mass spectrometry (ICP-MS) is a more power analytical tool than INAA-LLR [<xref ref-type="bibr" rid="scirp.74050-ref18">18</xref>] but sample digestion is a critical step in elemental analysis by this method. In the present study both analytical methods were used and the results obtained for some trace elements by ICP-MS were under the control of INAA-LLR data.</p><p>The present study had three aims. The main objective was to obtain reliable results about the 43 trace elements: Ag, Al, Au, B, Be, Bi, Br, Cd, Ce, Co, Cr, Cs, Dy, Er, Fe, Gd, Hg, Ho, La, Li, Mn, Mo, Nb, Nd, Ni, Pb, Pr, Rb, Sb, Sc, Se, Sm, Sn, Tb, Th, Ti, Tl, Tm, U, Y, Yb, Zn, and Zr contents in intact prostate of healthy men and in the prostate gland of BPH and PCa patients combining in consecutive order non-destructive INAA-LLR with destructive ICP-MS. The second aim was to compare the levels of trace elements in normal, hyperplastic, and cancerous prostate, and the third aim was to evaluate the trace element contents for diagnosis of prostate cancer.</p><p>All studies were approved by the Ethical Committee of the Medical Radiological Research Center, Obninsk.</p></sec><sec id="s2"><title>2. Materials and Methods</title><sec id="s2_1"><title>2.1. Materials</title><p>The patients studied (n = 92) were hospitalized in the Urological Department of the Medical Radiological Research Centre (Obninsk, Russia). All of them were European-Caucasian, citizens of Moscow and Obninsk (a small city in a non-industrial region 105 km south-west of Moscow). Transrectal puncture biopsy of suspicious indurated regions of the prostate was performed for every patient, to permit morphological study of prostatic tissue at these sites and to estimate their chemical element contents. For all patients the diagnosis has been confirmed by clinical and morphological results obtained during studies of biopsy and resected materials. The age of 32 patients with BPH ranged from 56 to 78 years, the mean being 66 &#177; 6 (M &#177; SD) years. The 60 patients aged 40 - 79 suffered from PCa (stage T1 - T4). Their mean age was 65 &#177; 10 (M &#177; SD) years. There were no any inclusion and exclusion criteria of patients. Samples of prostate tissue were obtained from all patients with BPH and PCa, who were in the hospital of Medical Radiological Research Center in period of this study.</p><p>Intact prostates (N) were removed at necropsy from 37 men aged 41 - 87 who had died suddenly. All deceased were European-Caucasian, citizens of Moscow. Their mean age was 55 &#177; 11 (M &#177; SD) years. The majority of deaths were due to trauma. Tissue samples were collected from the peripheral zone of dorsal and lateral lobes of their prostates, within 2 days of death and then the samples were divided into two portions. One was used for morphological study while the other was intended for trace element analysis. A histological examination was used to control the age norm conformity, as well as to confirm the absence of microadenomatosis and latent cancer [<xref ref-type="bibr" rid="scirp.74050-ref15">15</xref>] [<xref ref-type="bibr" rid="scirp.74050-ref20">20</xref>] [<xref ref-type="bibr" rid="scirp.74050-ref28">28</xref>] .</p><p>All tissue samples were divided into two portions. One was used for morphological study while the other was intended for trace element analysis. After the samples intended for trace element analysis were weighed, they were freeze-dried and homogenized. The sample weighing about 10 mg (for biopsy materials) and 50 - 100 mg (for resected materials) was used for trace element measurement by INAA-LLR. The samples for INAA-LLR were wrapped separately in a high-pur- ity aluminum foil washed with double rectified alcohol beforehand and placed in a nitric acid-washed quartz ampoule.</p><p>After NAA-LLR investigation the prostate samples were taken out and used for ICP-MS. The samples were decomposed in autoclaves; 1.5 mL of concentrated HNO<sub>3</sub> (nitric acid at 65%, maximum (max) of 0.0000005% Hg; GR, ISO, Merck) and 0.3 mL of H<sub>2</sub>O<sub>2</sub> (pure for analysis) were added to prostate tissue samples, placed in one-chamber autoclaves (Ancon-AT2, Ltd., Russia) and then heated for 3 h at 160˚C - 200˚C. After autoclaving, they were cooled to room temperature and solutions from the decomposed samples were diluted with deionized water (up to 20 mL) and transferred to plastic measuring bottles. Simultaneously, the same procedure was performed in autoclaves without tissue samples (only HNO<sub>3</sub> + H<sub>2</sub>O<sub>2</sub> + deionized water), and the resultant solutions were used as control samples.</p></sec><sec id="s2_2"><title>2.2. Methods</title><p>A vertical channel of a nuclear reactor was applied to determine the trace element mass fractions by NAA-LLR. The quartz ampoule with prostate samples and certified reference materials was soldered, positioned in a transport aluminum container and exposed to a 24-hour neutron irradiation in a vertical channel with a neutron flux of 1.3∙10<sup>13</sup> n&#215;cm<sup>−2</sup>∙s<sup>−1</sup>. Ten days after irradiation samples were reweighed and repacked. The samples were measured for period from 10 to 30 days after irradiation. The duration of measurements was from 20 min to 10 hours subject to pulse counting rate. The gamma spectrometer included the 100 cm<sup>3</sup> Ge (Li) detector and on-line computer-based multichannel analyzer. The spectrometer provided a resolution of 1.9 keV on the <sup>60</sup>Co 1332 keV line.</p><p>An ICP-MS Thermo-Fisher “X-7” Spectrometer (Thermo Electron, USA) was used to determine the content of trace elements by ICP-MS. The element concentrations in aqueous solutions were determined by the quantitative method using multi elemental calibration solutions ICP-MS-68A and ICP-AM-6-A produced by High-Purity Standards (Charleston, SC 29423, USA). Indium was used as an internal standard in all measurements.</p><p>Information detailing with the NAA-LLR and ICP-MS methods used and other details of the analysis was presented in our previous publication [<xref ref-type="bibr" rid="scirp.74050-ref15">15</xref>] [<xref ref-type="bibr" rid="scirp.74050-ref20">20</xref>] [<xref ref-type="bibr" rid="scirp.74050-ref28">28</xref>] [<xref ref-type="bibr" rid="scirp.74050-ref60">60</xref>] [<xref ref-type="bibr" rid="scirp.74050-ref66">66</xref>] .</p><p>For quality control, ten subsamples of the certified reference materials IAEA H-4 Animal muscle from the International Atomic Energy Agency (IAEA), as well as five sub-samples INCT-SBF-4 Soya Bean Flour, INCT-TL-1 Tea Leaves and INCT-MPH-2 Mixed Polish Herbs from the Institute of Nuclear Chemistry and Technology (INCT, Warszawa, Poland) were analyzed simultaneously with the investigated prostate tissue samples. All samples of CRM were treated in the same way as the prostate samples. Detailed results of this quality assurance program were presented in earlier publications [<xref ref-type="bibr" rid="scirp.74050-ref15">15</xref>] [<xref ref-type="bibr" rid="scirp.74050-ref18">18</xref>] [<xref ref-type="bibr" rid="scirp.74050-ref22">22</xref>] .</p><p>A dedicated computer program for INAA mode optimization was used [<xref ref-type="bibr" rid="scirp.74050-ref71">71</xref>] . All prostate samples for INAA-LLR were prepared in duplicate and mean values of chemical element contents were used in final calculation. For elements investigated by INAA-LLR and ICP-MS the mean of all results was used. Using the Microsoft Office Excel software arithmetic mean, standard deviation, and standard error of mean was calculated for trace element mass fraction in normal, benign hyperplastic and cancerous prostate tissue. The difference in the results between BPH and Norm, PCa and Norm, as well as PCA and BPH was evaluated by parametric Student’s t-test and non-parametric Wilcoxon-Mann-Whitney U-test. Values of p &lt; 0.05 were considered to be statistically significant. For the construction of “individual data sets for trace element mass fraction in normal, benign hypertrophic and cancerous prostate” diagrams the Microsoft Office Excel software was also used.</p></sec></sec><sec id="s3"><title>3. Results</title><p><xref ref-type="table" rid="table1">Table 1</xref> depicts mean values &#177; standard error of mean (M &#177; SEM) of the Ag, Al, Au, B, Be, Bi, Br, Cd, Ce, Co, Cr, Cs, Dy, Er, Fe, Gd, Hg, Ho, La, Li, Mn, Mo, Nb, Nd, Ni, Pb, Pr, Rb, Sb, Sc, Se, Sm, Sn, Tb, Th, Ti, Tl, Tm, U, Y, Yb, Zn and Zr mass fraction in normal, benign hypertrophic and cancerous prostate.</p><p>The ratios of means and the difference between mean values of Ag, Al, Au, B, Be, Bi, Br, Cd, Ce, Co, Cr, Cs, Dy, Er, Fe, Gd, Hg, Ho, La, Li, Mn, Mo, Nb, Nd, Ni, Pb, Pr, Rb, Sb, Sc, Se, Sm, Sn, Tb, Th, Ti, Tl, Tm, U, Y, Yb, Zn and Zr mass fraction in normal, benign hypertrophic and cancerous prostate are presented in <xref ref-type="table" rid="table2">Table 2</xref>.</p><p>Individual data sets for Ag, Al, B, Br, Li, Mn, Ni and Zn mass fraction in all investigated samples of normal, benign hypertrophic and cancerous prostate, respectively, are shown in <xref ref-type="fig" rid="fig1">Figure 1</xref>.</p><p><xref ref-type="table" rid="table3">Table 3</xref> contains parameters of the importance (sensitivity, specificity and accuracy) of Ag, Al, B, Br, Li, Mn, Ni and Zn mass fraction for the diagnosis of PCa calculated in this work.</p></sec><sec id="s4"><title>4. Discussion</title><p>As was shown by us [<xref ref-type="bibr" rid="scirp.74050-ref15">15</xref>] [<xref ref-type="bibr" rid="scirp.74050-ref18">18</xref>] [<xref ref-type="bibr" rid="scirp.74050-ref22">22</xref>] , the use of CRM IAEA H-4, INCT-SBF-4 Soya Bean Flour, INCT-TL-1 Tea Leaves, and INCT-MPH-2 Mixed Polish Herbs as certified reference materials for the analysis of samples of prostate tissue can be seen as quite acceptable. Good agreement of the Ag, Al, Au, B, Be, Bi, Br, Cd, Ce, Co, Cr, Cs, Dy, Er, Fe, Gd, Hg, Ho, La, Li, Mn, Mo, Nb, Nd, Ni, Pb, Pr, Rb, Sb, Sc, Se, Sm, Sn, Tb, Th, Ti, Tl, Tm, U, Y, Yb, Zn and Zr contents analyzed by INAA-LLR and ICP-MS with the certified data of reference materials indicates</p><table-wrap id="table1" ><label><xref ref-type="table" rid="table1">Table 1</xref></label><caption><title> Comparison of mean values (M &#177; SEM) of the trace element mass fraction (mg/kg, dry mass basis) in normal (N), benign hypertrophic (BPH) and cancerous prostate (PCa)</title></caption><table><tbody><thead><tr><th align="center" valign="middle"  rowspan="2"  >Element</th><th align="center" valign="middle"  rowspan="2"  >Symbol</th><th align="center" valign="middle"  colspan="3"  >Prostatic tissue</th></tr></thead><tr><td align="center" valign="middle" >Normal 41 - 87 year (n = 37)</td><td align="center" valign="middle" >BPH 56 - 78 year (n = 32)</td><td align="center" valign="middle" >PCa 40 - 79 year (n = 60)</td></tr><tr><td align="center" valign="middle" >Silver</td><td align="center" valign="middle" >Ag</td><td align="center" valign="middle" >0.038 &#177; 0.006</td><td align="center" valign="middle" >0.0415 &#177; 0.0090</td><td align="center" valign="middle" >0.252 &#177; 0.030</td></tr><tr><td align="center" valign="middle" >Aluminum</td><td align="center" valign="middle" >Al</td><td align="center" valign="middle" >34.2 &#177; 3.5</td><td align="center" valign="middle" >24.4 &#177; 3.2</td><td align="center" valign="middle" >328 &#177; 73</td></tr><tr><td align="center" valign="middle" >Gold</td><td align="center" valign="middle" >Au</td><td align="center" valign="middle" >0.0041 &#177; 0.0008</td><td align="center" valign="middle" >0.00257 &#177; 0.00077</td><td align="center" valign="middle" >0.0297 &#177; 0.0056</td></tr><tr><td align="center" valign="middle" >Boron</td><td align="center" valign="middle" >B</td><td align="center" valign="middle" >1.04 &#177; 0.18</td><td align="center" valign="middle" >1.51 &#177; 0.26</td><td align="center" valign="middle" >12.6 &#177; 3,7</td></tr><tr><td align="center" valign="middle" >Berillium</td><td align="center" valign="middle" >Be</td><td align="center" valign="middle" >0.00094 &#177; 0.00007</td><td align="center" valign="middle" >0.000918 &#177; 0.000042</td><td align="center" valign="middle" >0.0137 &#177; 0.0022</td></tr><tr><td align="center" valign="middle" >Bismuth</td><td align="center" valign="middle" >Bi</td><td align="center" valign="middle" >0.029 &#177; 0.011</td><td align="center" valign="middle" >0.140 &#177; 0.042</td><td align="center" valign="middle" >1.75 &#177; 0.27</td></tr><tr><td align="center" valign="middle" >Bromine</td><td align="center" valign="middle" >Br</td><td align="center" valign="middle" >27.9 &#177; 2.9</td><td align="center" valign="middle" >30.6 &#177; 3.4</td><td align="center" valign="middle" >99.9 &#177; 8.9</td></tr><tr><td align="center" valign="middle" >Cadmium</td><td align="center" valign="middle" >Cd</td><td align="center" valign="middle" >1.12 &#177; 0.13</td><td align="center" valign="middle" >1.07 &#177; 0.43</td><td align="center" valign="middle" >0.425 &#177; 0.099</td></tr><tr><td align="center" valign="middle" >Cerium</td><td align="center" valign="middle" >Ce</td><td align="center" valign="middle" >0.0309 &#177; 0.0050</td><td align="center" valign="middle" >0.0128 &#177; 0.0019</td><td align="center" valign="middle" >0.101 &#177; 0.013</td></tr><tr><td align="center" valign="middle" >Cobalt</td><td align="center" valign="middle" >Co</td><td align="center" valign="middle" >0.0467 &#177; 0.0064</td><td align="center" valign="middle" >0.0617 &#177; 0.0084</td><td align="center" valign="middle" >0.0336 &#177; 0.0040</td></tr><tr><td align="center" valign="middle" >Cromium</td><td align="center" valign="middle" >Cr</td><td align="center" valign="middle" >0.56 &#177; 0.08</td><td align="center" valign="middle" >1.00 &#177; 0.10</td><td align="center" valign="middle" >2.34 &#177; 0.32</td></tr><tr><td align="center" valign="middle" >Cesium</td><td align="center" valign="middle" >Cs</td><td align="center" valign="middle" >0.0339 &#177; 0.0033</td><td align="center" valign="middle" >0.0235 &#177; 0.0025</td><td align="center" valign="middle" >0.0389 &#177; 0.0039</td></tr><tr><td align="center" valign="middle" >Dysprosium</td><td align="center" valign="middle" >Dy</td><td align="center" valign="middle" >0.00293 &#177; 0.00049</td><td align="center" valign="middle" >0.00156 &#177; 0.00024</td><td align="center" valign="middle" >0.00771 &#177; 0.00110</td></tr><tr><td align="center" valign="middle" >Erbium</td><td align="center" valign="middle" >Er</td><td align="center" valign="middle" >0.00148 &#177; 0.00023</td><td align="center" valign="middle" >0.00072 &#177; 0.00013</td><td align="center" valign="middle" >0.00297 &#177; 0.00038</td></tr><tr><td align="center" valign="middle" >Iron</td><td align="center" valign="middle" >Fe</td><td align="center" valign="middle" >111 &#177; 9</td><td align="center" valign="middle" >133 &#177; 11</td><td align="center" valign="middle" >165 &#177; 15</td></tr><tr><td align="center" valign="middle" >Gadolinium</td><td align="center" valign="middle" >Gd</td><td align="center" valign="middle" >0.00290 &#177; 0.00041</td><td align="center" valign="middle" >0.00153 &#177; 0.00027</td><td align="center" valign="middle" >0.00945 &#177; 0.00173</td></tr><tr><td align="center" valign="middle" >Mercury</td><td align="center" valign="middle" >Hg</td><td align="center" valign="middle" >0.052 &#177; 0.008</td><td align="center" valign="middle" >0.259 &#177; 0.029</td><td align="center" valign="middle" >0.122 &#177; 0.019</td></tr><tr><td align="center" valign="middle" >Holmium</td><td align="center" valign="middle" >Ho</td><td align="center" valign="middle" >0.00057 &#177; 0.00008</td><td align="center" valign="middle" >0.00032 &#177; 0.00005</td><td align="center" valign="middle" >0.00178 &#177; 0.00022</td></tr><tr><td align="center" valign="middle" >Lanthanum</td><td align="center" valign="middle" >La</td><td align="center" valign="middle" >0.080 &#177; 0.020</td><td align="center" valign="middle" >0.0385 &#177; 0.0073</td><td align="center" valign="middle" >0.969 &#177; 0.537</td></tr><tr><td align="center" valign="middle" >Lithium</td><td align="center" valign="middle" >Li</td><td align="center" valign="middle" >0.0419 &#177; 0.0055</td><td align="center" valign="middle" >0.0385 &#177; 0.0073</td><td align="center" valign="middle" >0.251 &#177; 0.054</td></tr><tr><td align="center" valign="middle" >Manganese</td><td align="center" valign="middle" >Mn</td><td align="center" valign="middle" >1.34 &#177; 0.08</td><td align="center" valign="middle" >1.19 &#177; 0.09</td><td align="center" valign="middle" >6.99 &#177; 1.35</td></tr><tr><td align="center" valign="middle" >Molybdenum</td><td align="center" valign="middle" >Mo</td><td align="center" valign="middle" >0.282 &#177; 0.038</td><td align="center" valign="middle" >0.167 &#177; 0.009</td><td align="center" valign="middle" >0.298 &#177; 0.035</td></tr><tr><td align="center" valign="middle" >Niobium</td><td align="center" valign="middle" >Nb</td><td align="center" valign="middle" >0.0054 &#177; 0.0012</td><td align="center" valign="middle" >0.0102 &#177; 0.0079</td><td align="center" valign="middle" >0.0052 &#177; 0.0002</td></tr><tr><td align="center" valign="middle" >Neodymium</td><td align="center" valign="middle" >Nd</td><td align="center" valign="middle" >0.0137 &#177; 0.0021</td><td align="center" valign="middle" >0.0062 &#177; 0.0009</td><td align="center" valign="middle" >0.0413 &#177; 0.0065</td></tr><tr><td align="center" valign="middle" >Nickel</td><td align="center" valign="middle" >Ni</td><td align="center" valign="middle" >3.10 &#177; 0.51</td><td align="center" valign="middle" >3.22 &#177; 1.06</td><td align="center" valign="middle" >6.96 &#177; 1.04</td></tr><tr><td align="center" valign="middle" >Lead</td><td align="center" valign="middle" >Pb</td><td align="center" valign="middle" >2.39 &#177; 0.56</td><td align="center" valign="middle" >0.69 &#177; 0.16</td><td align="center" valign="middle" >1.81 &#177; 0.35</td></tr><tr><td align="center" valign="middle" >Praseodymium</td><td align="center" valign="middle" >Pr</td><td align="center" valign="middle" >0.00353 &#177; 0.00053</td><td align="center" valign="middle" >0.00149 &#177; 0.00027</td><td align="center" valign="middle" >0.00973 &#177; 0.00174</td></tr><tr><td align="center" valign="middle" >Rubidium</td><td align="center" valign="middle" >Rb</td><td align="center" valign="middle" >13.3 &#177; 0.9</td><td align="center" valign="middle" >14.3 &#177; 0.8</td><td align="center" valign="middle" >8.71 &#177; 0.66</td></tr><tr><td align="center" valign="middle" >Antimony</td><td align="center" valign="middle" >Sb</td><td align="center" valign="middle" >0.043 &#177; 0.006</td><td align="center" valign="middle" >0.163 &#177; 0.036</td><td align="center" valign="middle" >0.490 &#177; 0.059</td></tr><tr><td align="center" valign="middle" >Scandium</td><td align="center" valign="middle" >Sc</td><td align="center" valign="middle" >0.0294 &#177; 0.0053</td><td align="center" valign="middle" >0.0257 &#177; 0.0040</td><td align="center" valign="middle" >0.0116 &#177; 0.0015</td></tr><tr><td align="center" valign="middle" >Selenium</td><td align="center" valign="middle" >Se</td><td align="center" valign="middle" >0.75 &#177; 0.05</td><td align="center" valign="middle" >1.11 &#177; 0.07</td><td align="center" valign="middle" >0.56 &#177; 0.08</td></tr><tr><td align="center" valign="middle" >Samarium</td><td align="center" valign="middle" >Sm</td><td align="center" valign="middle" >0.0027 &#177; 0.0004</td><td align="center" valign="middle" >0.0014 &#177; 0.0004</td><td align="center" valign="middle" >0.0095 &#177; 0.0029</td></tr><tr><td align="center" valign="middle" >Tin</td><td align="center" valign="middle" >Sn</td><td align="center" valign="middle" >0.32 &#177; 0.06</td><td align="center" valign="middle" >0.108 &#177; 0.029</td><td align="center" valign="middle" >1.28 &#177; 0.24</td></tr><tr><td align="center" valign="middle" >Terbium</td><td align="center" valign="middle" >Tb</td><td align="center" valign="middle" >0.00039 &#177; 0.00006</td><td align="center" valign="middle" >0.00017 &#177; 0.00003</td><td align="center" valign="middle" >0.00089 &#177; 0.00012</td></tr><tr><td align="center" valign="middle" >Thorium</td><td align="center" valign="middle" >Th</td><td align="center" valign="middle" >0.0033 &#177; 0.0007</td><td align="center" valign="middle" >0.0018 &#177; 0.0003</td><td align="center" valign="middle" >0.0495 &#177; 0.0123</td></tr><tr><td align="center" valign="middle" >Titanium*</td><td align="center" valign="middle" >Ti*</td><td align="center" valign="middle" >2.82 &#177; 0.64</td><td align="center" valign="middle" >1.52 &#177; 0.20</td><td align="center" valign="middle" >8.60 &#177; 2.20</td></tr><tr><td align="center" valign="middle" >Thallium</td><td align="center" valign="middle" >Tl</td><td align="center" valign="middle" >0.0014 &#177; 0.0001</td><td align="center" valign="middle" >0.00202 &#177; 0.00057</td><td align="center" valign="middle" >0.0219 &#177; 0.0056</td></tr><tr><td align="center" valign="middle" >Thulium</td><td align="center" valign="middle" >Tm</td><td align="center" valign="middle" >0.00024 &#177; 0.00003</td><td align="center" valign="middle" >0.000151 &#177; 0.000021</td><td align="center" valign="middle" >0.000535 &#177; 0.000111</td></tr><tr><td align="center" valign="middle" >Uranium</td><td align="center" valign="middle" >U</td><td align="center" valign="middle" >0.0070 &#177; 0.0021</td><td align="center" valign="middle" >0.0021 &#177; 0.0009</td><td align="center" valign="middle" >0.0068 &#177; 0.0013</td></tr><tr><td align="center" valign="middle" >Yttrium</td><td align="center" valign="middle" >Y</td><td align="center" valign="middle" >0.0187 &#177; 0.0043</td><td align="center" valign="middle" >0.0071 &#177; 0.0012</td><td align="center" valign="middle" >0.0340 &#177; 0.0038</td></tr><tr><td align="center" valign="middle" >Ytterbium</td><td align="center" valign="middle" >Yb</td><td align="center" valign="middle" >0.00141 &#177; 0.00025</td><td align="center" valign="middle" >0.00083 &#177; 0.00020</td><td align="center" valign="middle" >0.00174 &#177; 0.00039</td></tr><tr><td align="center" valign="middle" >Zinc</td><td align="center" valign="middle" >Zn</td><td align="center" valign="middle" >1031 &#177; 129</td><td align="center" valign="middle" >1271 &#177; 102</td><td align="center" valign="middle" >136 &#177; 10</td></tr><tr><td align="center" valign="middle" >Zirconium</td><td align="center" valign="middle" >Zr</td><td align="center" valign="middle" >0.036 &#177; 0.006</td><td align="center" valign="middle" >0.091 &#177; 0.036</td><td align="center" valign="middle" >2.13 &#177; 0.89</td></tr></tbody></table></table-wrap><p>M―arithmetic mean, SEM―standard error of mean, *Titanium tools were used for sampling and sample preparation.</p><table-wrap id="table2" ><label><xref ref-type="table" rid="table2">Table 2</xref></label><caption><title> Ratio of means and the difference between mean values of trace element mass fractions in normal (N), benign hypertrophic (BPH) and cancerous prostate (PCa)</title></caption><table><tbody><thead><tr><th align="center" valign="middle"  rowspan="2"  ></th><th align="center" valign="middle"  colspan="3"  >BPH and Normal (N)</th><th align="center" valign="middle"  colspan="3"  >PCa and Normal (N)</th><th align="center" valign="middle"  colspan="3"  >PCa and BPH</th></tr></thead><tr><td align="center" valign="middle" >Ratio BPH/N</td><td align="center" valign="middle" >p ≤ t-test</td><td align="center" valign="middle" >p U-test</td><td align="center" valign="middle" >Ratio PCa/N</td><td align="center" valign="middle" >p ≤ t-test</td><td align="center" valign="middle" >p U-test</td><td align="center" valign="middle" >Ratio PCa/BPH</td><td align="center" valign="middle" >p ≤ t-test</td><td align="center" valign="middle" >p U-test</td></tr><tr><td align="center" valign="middle" >Ag</td><td align="center" valign="middle" >1.09</td><td align="center" valign="middle" >0.74</td><td align="center" valign="middle" >&gt;0.05</td><td align="center" valign="middle" >6.63</td><td align="center" valign="middle" >0.001</td><td align="center" valign="middle" >&lt;0.01</td><td align="center" valign="middle" >6.07</td><td align="center" valign="middle" >0.001</td><td align="center" valign="middle" >&lt;0.01</td></tr><tr><td align="center" valign="middle" >Al</td><td align="center" valign="middle" >0.71</td><td align="center" valign="middle" >0.052</td><td align="center" valign="middle" >&gt;0.05</td><td align="center" valign="middle" >9.59</td><td align="center" valign="middle" >0.003</td><td align="center" valign="middle" >&lt;0.01</td><td align="center" valign="middle" >13.4</td><td align="center" valign="middle" >0.002</td><td align="center" valign="middle" >&lt;0.01</td></tr><tr><td align="center" valign="middle" >Au</td><td align="center" valign="middle" >0.63</td><td align="center" valign="middle" >0.17</td><td align="center" valign="middle" >&gt;0.05</td><td align="center" valign="middle" >7.24</td><td align="center" valign="middle" >0.001</td><td align="center" valign="middle" >&lt;0.01</td><td align="center" valign="middle" >11.6</td><td align="center" valign="middle" >0.001</td><td align="center" valign="middle" >&lt;0.01</td></tr><tr><td align="center" valign="middle" >B</td><td align="center" valign="middle" >1.45</td><td align="center" valign="middle" >0.16</td><td align="center" valign="middle" >&gt;0.05</td><td align="center" valign="middle" >12.1</td><td align="center" valign="middle" >0.012</td><td align="center" valign="middle" >&lt;0.01</td><td align="center" valign="middle" >8.34</td><td align="center" valign="middle" >0.015</td><td align="center" valign="middle" >&lt;0.01</td></tr><tr><td align="center" valign="middle" >Be</td><td align="center" valign="middle" >0.98</td><td align="center" valign="middle" >0.78</td><td align="center" valign="middle" >&gt;0.05</td><td align="center" valign="middle" >14.6</td><td align="center" valign="middle" >0.001</td><td align="center" valign="middle" >&lt;0.01</td><td align="center" valign="middle" >14.9</td><td align="center" valign="middle" >0.001</td><td align="center" valign="middle" >&lt;0.01</td></tr><tr><td align="center" valign="middle" >Bi</td><td align="center" valign="middle" >4.83</td><td align="center" valign="middle" >0.026</td><td align="center" valign="middle" >&gt;0.05</td><td align="center" valign="middle" >60.3</td><td align="center" valign="middle" >0.001</td><td align="center" valign="middle" >&lt;0.01</td><td align="center" valign="middle" >12.5</td><td align="center" valign="middle" >0.001</td><td align="center" valign="middle" >&lt;0.01</td></tr><tr><td align="center" valign="middle" >Br</td><td align="center" valign="middle" >1.10</td><td align="center" valign="middle" >0.53</td><td align="center" valign="middle" >&gt;0.05</td><td align="center" valign="middle" >3.58</td><td align="center" valign="middle" >0.001</td><td align="center" valign="middle" >&lt;0.01</td><td align="center" valign="middle" >3.26</td><td align="center" valign="middle" >0.001</td><td align="center" valign="middle" >&lt;0.01</td></tr><tr><td align="center" valign="middle" >Cd</td><td align="center" valign="middle" >0.96</td><td align="center" valign="middle" >0.95</td><td align="center" valign="middle" >&gt;0.05</td><td align="center" valign="middle" >0.38</td><td align="center" valign="middle" >0.001</td><td align="center" valign="middle" >&lt;0.05</td><td align="center" valign="middle" >0.40</td><td align="center" valign="middle" >0.17</td><td align="center" valign="middle" >&gt;0.05</td></tr><tr><td align="center" valign="middle" >Ce</td><td align="center" valign="middle" >0.41</td><td align="center" valign="middle" >0.002</td><td align="center" valign="middle" >&gt;0.05</td><td align="center" valign="middle" >3,27</td><td align="center" valign="middle" >0.001</td><td align="center" valign="middle" >&lt;0.01</td><td align="center" valign="middle" >7.89</td><td align="center" valign="middle" >0.001</td><td align="center" valign="middle" >&lt;0.01</td></tr><tr><td align="center" valign="middle" >Co</td><td align="center" valign="middle" >1.32</td><td align="center" valign="middle" >0.16</td><td align="center" valign="middle" >&gt;0.05</td><td align="center" valign="middle" >0.72</td><td align="center" valign="middle" >0.087</td><td align="center" valign="middle" >&gt;0.05</td><td align="center" valign="middle" >0.54</td><td align="center" valign="middle" >0.005</td><td align="center" valign="middle" >&gt;0.05</td></tr><tr><td align="center" valign="middle" >Cr</td><td align="center" valign="middle" >1.79</td><td align="center" valign="middle" >0.002</td><td align="center" valign="middle" >&lt;0.01</td><td align="center" valign="middle" >4.18</td><td align="center" valign="middle" >0.001</td><td align="center" valign="middle" >&lt;0.01</td><td align="center" valign="middle" >2.34</td><td align="center" valign="middle" >0.001</td><td align="center" valign="middle" >&lt;0.01</td></tr><tr><td align="center" valign="middle" >Cs</td><td align="center" valign="middle" >0.69</td><td align="center" valign="middle" >0.017</td><td align="center" valign="middle" >&gt;0.05</td><td align="center" valign="middle" >1.15</td><td align="center" valign="middle" >0.33</td><td align="center" valign="middle" >&gt;0.05</td><td align="center" valign="middle" >1.66</td><td align="center" valign="middle" >0.004</td><td align="center" valign="middle" >&lt;0.01</td></tr><tr><td align="center" valign="middle" >Dy</td><td align="center" valign="middle" >0.53</td><td align="center" valign="middle" >0.018</td><td align="center" valign="middle" >&gt;0.05</td><td align="center" valign="middle" >2.63</td><td align="center" valign="middle" >0.003</td><td align="center" valign="middle" >&lt;0.05</td><td align="center" valign="middle" >4.94</td><td align="center" valign="middle" >0.001</td><td align="center" valign="middle" >&lt;0.01</td></tr><tr><td align="center" valign="middle" >Er</td><td align="center" valign="middle" >0.49</td><td align="center" valign="middle" >0.007</td><td align="center" valign="middle" >&gt;0.05</td><td align="center" valign="middle" >2.01</td><td align="center" valign="middle" >0.004</td><td align="center" valign="middle" >&lt;0.05</td><td align="center" valign="middle" >4.13</td><td align="center" valign="middle" >0.001</td><td align="center" valign="middle" >&lt;0.01</td></tr><tr><td align="center" valign="middle" >Fe</td><td align="center" valign="middle" >1.20</td><td align="center" valign="middle" >0.13</td><td align="center" valign="middle" >&gt;0.05</td><td align="center" valign="middle" >1.49</td><td align="center" valign="middle" >0.004</td><td align="center" valign="middle" >&lt;0.05</td><td align="center" valign="middle" >1.24</td><td align="center" valign="middle" >0.10</td><td align="center" valign="middle" >&gt;0.05</td></tr><tr><td align="center" valign="middle" >Gd</td><td align="center" valign="middle" >0.53</td><td align="center" valign="middle" >0.008</td><td align="center" valign="middle" >&gt;0.05</td><td align="center" valign="middle" >3.26</td><td align="center" valign="middle" >0.004</td><td align="center" valign="middle" >&lt;0.01</td><td align="center" valign="middle" >6.18</td><td align="center" valign="middle" >0.001</td><td align="center" valign="middle" >&lt;0.01</td></tr><tr><td align="center" valign="middle" >Hg</td><td align="center" valign="middle" >4.98</td><td align="center" valign="middle" >0.001</td><td align="center" valign="middle" >&lt;0.01</td><td align="center" valign="middle" >2.35</td><td align="center" valign="middle" >0.002</td><td align="center" valign="middle" >&lt;0.01</td><td align="center" valign="middle" >0.47</td><td align="center" valign="middle" >0.004</td><td align="center" valign="middle" >&lt;0.01</td></tr><tr><td align="center" valign="middle" >Ho</td><td align="center" valign="middle" >0.56</td><td align="center" valign="middle" >0.012</td><td align="center" valign="middle" >&gt;0.05</td><td align="center" valign="middle" >3.12</td><td align="center" valign="middle" >0.001</td><td align="center" valign="middle" >&lt;0.01</td><td align="center" valign="middle" >5.56</td><td align="center" valign="middle" >0.001</td><td align="center" valign="middle" >&lt;0.01</td></tr><tr><td align="center" valign="middle" >La</td><td align="center" valign="middle" >0.48</td><td align="center" valign="middle" >0.005</td><td align="center" valign="middle" >&gt;0.05</td><td align="center" valign="middle" >12.1</td><td align="center" valign="middle" >0.132</td><td align="center" valign="middle" >&gt;0.05</td><td align="center" valign="middle" >25.2</td><td align="center" valign="middle" >0.11</td><td align="center" valign="middle" >&lt;0.01</td></tr><tr><td align="center" valign="middle" >Li</td><td align="center" valign="middle" >0.92</td><td align="center" valign="middle" >0.71</td><td align="center" valign="middle" >&gt;0.05</td><td align="center" valign="middle" >5.99</td><td align="center" valign="middle" >0.003</td><td align="center" valign="middle" >&lt;0.01</td><td align="center" valign="middle" >6.52</td><td align="center" valign="middle" >0.003</td><td align="center" valign="middle" >&lt;0.01</td></tr><tr><td align="center" valign="middle" >Mn</td><td align="center" valign="middle" >0.89</td><td align="center" valign="middle" >0.25</td><td align="center" valign="middle" >&gt;0.05</td><td align="center" valign="middle" >5.22</td><td align="center" valign="middle" >0.002</td><td align="center" valign="middle" >&lt;0.01</td><td align="center" valign="middle" >5.87</td><td align="center" valign="middle" >0.002</td><td align="center" valign="middle" >&lt;0.01</td></tr><tr><td align="center" valign="middle" >Mo</td><td align="center" valign="middle" >0.59</td><td align="center" valign="middle" >0.007</td><td align="center" valign="middle" >&lt;0.05</td><td align="center" valign="middle" >1.06</td><td align="center" valign="middle" >0.76</td><td align="center" valign="middle" >&gt;0.05</td><td align="center" valign="middle" >1.78</td><td align="center" valign="middle" >0.018</td><td align="center" valign="middle" >=0.05</td></tr><tr><td align="center" valign="middle" >Nb</td><td align="center" valign="middle" >1.89</td><td align="center" valign="middle" >0.56</td><td align="center" valign="middle" >&gt;0.05</td><td align="center" valign="middle" >0.96</td><td align="center" valign="middle" >0.82</td><td align="center" valign="middle" >&gt;0.05</td><td align="center" valign="middle" >0.51</td><td align="center" valign="middle" >0.53</td><td align="center" valign="middle" >&gt;0.05</td></tr><tr><td align="center" valign="middle" >Nd</td><td align="center" valign="middle" >0.45</td><td align="center" valign="middle" >0.003</td><td align="center" valign="middle" >&lt;0.01</td><td align="center" valign="middle" >3.01</td><td align="center" valign="middle" >0.002</td><td align="center" valign="middle" >&lt;0.01</td><td align="center" valign="middle" >6.66</td><td align="center" valign="middle" >0.001</td><td align="center" valign="middle" >&lt;0.01</td></tr><tr><td align="center" valign="middle" >Ni</td><td align="center" valign="middle" >1.04</td><td align="center" valign="middle" >0.92</td><td align="center" valign="middle" >&gt;0.05</td><td align="center" valign="middle" >2.25</td><td align="center" valign="middle" >0.005</td><td align="center" valign="middle" >&lt;0.01</td><td align="center" valign="middle" >2.16</td><td align="center" valign="middle" >0.020</td><td align="center" valign="middle" >&lt;0.01</td></tr><tr><td align="center" valign="middle" >Pb</td><td align="center" valign="middle" >0.29</td><td align="center" valign="middle" >0.007</td><td align="center" valign="middle" >&gt;0.05</td><td align="center" valign="middle" >0.76</td><td align="center" valign="middle" >0.38</td><td align="center" valign="middle" >&gt;0.05</td><td align="center" valign="middle" >2.62</td><td align="center" valign="middle" >0.011</td><td align="center" valign="middle" >&lt;0.01</td></tr><tr><td align="center" valign="middle" >Pr</td><td align="center" valign="middle" >0.42</td><td align="center" valign="middle" >0.002</td><td align="center" valign="middle" >&lt;0.05</td><td align="center" valign="middle" >2.76</td><td align="center" valign="middle" >0.005</td><td align="center" valign="middle" >&lt;0.01</td><td align="center" valign="middle" >6.53</td><td align="center" valign="middle" >0.001</td><td align="center" valign="middle" >&lt;0.01</td></tr><tr><td align="center" valign="middle" >Rb</td><td align="center" valign="middle" >1.08</td><td align="center" valign="middle" >0.42</td><td align="center" valign="middle" >&gt;0.05</td><td align="center" valign="middle" >0.65</td><td align="center" valign="middle" >0.001</td><td align="center" valign="middle" >&lt;0.01</td><td align="center" valign="middle" >0.61</td><td align="center" valign="middle" >0.001</td><td align="center" valign="middle" >&lt;0.01</td></tr><tr><td align="center" valign="middle" >Sb</td><td align="center" valign="middle" >3.79</td><td align="center" valign="middle" >0.004</td><td align="center" valign="middle" >&gt;0.05</td><td align="center" valign="middle" >11.4</td><td align="center" valign="middle" >0.001</td><td align="center" valign="middle" >&lt;0.01</td><td align="center" valign="middle" >3.01</td><td align="center" valign="middle" >0.001</td><td align="center" valign="middle" >&lt;0.01</td></tr><tr><td align="center" valign="middle" >Sc</td><td align="center" valign="middle" >0.87</td><td align="center" valign="middle" >0.58</td><td align="center" valign="middle" >&gt;0.05</td><td align="center" valign="middle" >0.39</td><td align="center" valign="middle" >0.004</td><td align="center" valign="middle" >&lt;0.01</td><td align="center" valign="middle" >0.45</td><td align="center" valign="middle" >0.004</td><td align="center" valign="middle" >&lt;0.01</td></tr><tr><td align="center" valign="middle" >Se</td><td align="center" valign="middle" >1.48</td><td align="center" valign="middle" >0.001</td><td align="center" valign="middle" >&lt;0.05</td><td align="center" valign="middle" >0.75</td><td align="center" valign="middle" >0.041</td><td align="center" valign="middle" >&lt;0.05</td><td align="center" valign="middle" >0.50</td><td align="center" valign="middle" >0.001</td><td align="center" valign="middle" >&lt;0.01</td></tr><tr><td align="center" valign="middle" >Sm</td><td align="center" valign="middle" >0.52</td><td align="center" valign="middle" >0.023</td><td align="center" valign="middle" >&gt;0.05</td><td align="center" valign="middle" >3.52</td><td align="center" valign="middle" >0.039</td><td align="center" valign="middle" >&lt;0.05</td><td align="center" valign="middle" >6.79</td><td align="center" valign="middle" >0.019</td><td align="center" valign="middle" >&lt;0.05</td></tr><tr><td align="center" valign="middle" >Sn</td><td align="center" valign="middle" >0.34</td><td align="center" valign="middle" >0.005</td><td align="center" valign="middle" >&lt;0.01</td><td align="center" valign="middle" >4.00</td><td align="center" valign="middle" >0.002</td><td align="center" valign="middle" >&lt;0.01</td><td align="center" valign="middle" >11.9</td><td align="center" valign="middle" >0.001</td><td align="center" valign="middle" >&lt;0.01</td></tr><tr><td align="center" valign="middle" >Tb</td><td align="center" valign="middle" >0.44</td><td align="center" valign="middle" >0.002</td><td align="center" valign="middle" >&lt;0.05</td><td align="center" valign="middle" >2.28</td><td align="center" valign="middle" >0.008</td><td align="center" valign="middle" >&lt;0.01</td><td align="center" valign="middle" >5.24</td><td align="center" valign="middle" >0.003</td><td align="center" valign="middle" >&lt;0.01</td></tr><tr><td align="center" valign="middle" >Th</td><td align="center" valign="middle" >0.55</td><td align="center" valign="middle" >0.066</td><td align="center" valign="middle" >&gt;0.05</td><td align="center" valign="middle" >15.0</td><td align="center" valign="middle" >0.004</td><td align="center" valign="middle" >&lt;0.01</td><td align="center" valign="middle" >27.5</td><td align="center" valign="middle" >0.003</td><td align="center" valign="middle" >&lt;0.01</td></tr><tr><td align="center" valign="middle" >Ti*</td><td align="center" valign="middle" >0.53</td><td align="center" valign="middle" >0.064</td><td align="center" valign="middle" >&gt;0.05</td><td align="center" valign="middle" >3.05</td><td align="center" valign="middle" >0.056</td><td align="center" valign="middle" >&gt;0.05</td><td align="center" valign="middle" >5.73</td><td align="center" valign="middle" >0.032</td><td align="center" valign="middle" >&gt;0.05</td></tr><tr><td align="center" valign="middle" >Tl</td><td align="center" valign="middle" >1.44</td><td align="center" valign="middle" >0.30</td><td align="center" valign="middle" >&gt;0.05</td><td align="center" valign="middle" >15.6</td><td align="center" valign="middle" >0.004</td><td align="center" valign="middle" >&lt;0.01</td><td align="center" valign="middle" >10.8</td><td align="center" valign="middle" >0.005</td><td align="center" valign="middle" >&lt;0.01</td></tr><tr><td align="center" valign="middle" >Tm</td><td align="center" valign="middle" >0.63</td><td align="center" valign="middle" >0.033</td><td align="center" valign="middle" >&gt;0.05</td><td align="center" valign="middle" >2.23</td><td align="center" valign="middle" >0.072</td><td align="center" valign="middle" >&lt;0.05</td><td align="center" valign="middle" >3.54</td><td align="center" valign="middle" >0.038</td><td align="center" valign="middle" >&lt;0.01</td></tr><tr><td align="center" valign="middle" >U</td><td align="center" valign="middle" >0.30</td><td align="center" valign="middle" >0.041</td><td align="center" valign="middle" >&gt;0.05</td><td align="center" valign="middle" >0.97</td><td align="center" valign="middle" >0.95</td><td align="center" valign="middle" >&gt;0.05</td><td align="center" valign="middle" >3.24</td><td align="center" valign="middle" >0.008</td><td align="center" valign="middle" >&lt;0.01</td></tr><tr><td align="center" valign="middle" >Y</td><td align="center" valign="middle" >0.38</td><td align="center" valign="middle" >0.014</td><td align="center" valign="middle" >&gt;0.05</td><td align="center" valign="middle" >1.82</td><td align="center" valign="middle" >0.012</td><td align="center" valign="middle" >&lt;0.01</td><td align="center" valign="middle" >4.79</td><td align="center" valign="middle" >0.001</td><td align="center" valign="middle" >&lt;0.01</td></tr><tr><td align="center" valign="middle" >Yb</td><td align="center" valign="middle" >0.59</td><td align="center" valign="middle" >0.074</td><td align="center" valign="middle" >&gt;0.05</td><td align="center" valign="middle" >1.23</td><td align="center" valign="middle" >0.50</td><td align="center" valign="middle" >&gt;0.05</td><td align="center" valign="middle" >2.10</td><td align="center" valign="middle" >0.080</td><td align="center" valign="middle" >&gt;0.05</td></tr><tr><td align="center" valign="middle" >Zn</td><td align="center" valign="middle" >1.23</td><td align="center" valign="middle" >0.15</td><td align="center" valign="middle" >&gt;0.05</td><td align="center" valign="middle" >0.13</td><td align="center" valign="middle" >0.001</td><td align="center" valign="middle" >&lt;0.01</td><td align="center" valign="middle" >0.11</td><td align="center" valign="middle" >0.001</td><td align="center" valign="middle" >&lt;0.01</td></tr><tr><td align="center" valign="middle" >Zr</td><td align="center" valign="middle" >2.53</td><td align="center" valign="middle" >0.17</td><td align="center" valign="middle" >&gt;0.05</td><td align="center" valign="middle" >59.2</td><td align="center" valign="middle" >0.041</td><td align="center" valign="middle" >&lt;0.05</td><td align="center" valign="middle" >23.4</td><td align="center" valign="middle" >0.045</td><td align="center" valign="middle" >&lt;0.01</td></tr></tbody></table></table-wrap><p>t-test―Student’s t-test, U-test―Wilcoxon-Mann-Whitney U-test, Bold significant differences.</p><fig id="fig1"  position="float"><label><xref ref-type="fig" rid="fig1">Figure 1</xref></label><caption><title> Individual data sets for Ag, Al, B, Br, Li, Mn, Ni and Zn mass fraction in samples of normal (1), benign hypertrophic (2) and cancerous (3) prostate</title></caption><graphic mimetype="image"   position="float"  xlink:type="simple"  xlink:href="http://html.scirp.org/file/5-8902486x2.png"/></fig><table-wrap id="table3" ><label><xref ref-type="table" rid="table3">Table 3</xref></label><caption><title> Parameters (M &#177; SD) of the importance (sensitivity, specificity and accuracy) of Al, B, Mn, and Zn mass fraction for the diagnosis of PCa (estimation is made for “PCa or normal and BPH prostate”)</title></caption><table><tbody><thead><tr><th align="center" valign="middle" >Mass fraction</th><th align="center" valign="middle" >Limit for PCa mg/kg dry tissue</th><th align="center" valign="middle" >Sensitivity</th><th align="center" valign="middle" >Specificity</th><th align="center" valign="middle" >Accuracy</th></tr></thead><tr><td align="center" valign="middle" >Ag</td><td align="center" valign="middle" >≥0.085</td><td align="center" valign="middle" >88 &#177; 6</td><td align="center" valign="middle" >92 &#177; 4</td><td align="center" valign="middle" >92 &#177; 3</td></tr><tr><td align="center" valign="middle" >Al</td><td align="center" valign="middle" >≥100</td><td align="center" valign="middle" >72 &#177; 14</td><td align="center" valign="middle" >100 − 3</td><td align="center" valign="middle" >94 &#177; 3</td></tr><tr><td align="center" valign="middle" >B</td><td align="center" valign="middle" >≥4.0</td><td align="center" valign="middle" >90 &#177; 10</td><td align="center" valign="middle" >100 − 3</td><td align="center" valign="middle" >98 &#177; 2</td></tr><tr><td align="center" valign="middle" >Br</td><td align="center" valign="middle" >≥60</td><td align="center" valign="middle" >83 &#177; 8</td><td align="center" valign="middle" >92 &#177; 4</td><td align="center" valign="middle" >89 &#177; 4</td></tr><tr><td align="center" valign="middle" >Li</td><td align="center" valign="middle" >≥0.08</td><td align="center" valign="middle" >82 &#177; 12</td><td align="center" valign="middle" >91 &#177; 5</td><td align="center" valign="middle" >89 &#177; 4</td></tr><tr><td align="center" valign="middle" >Mn</td><td align="center" valign="middle" >≥2.0</td><td align="center" valign="middle" >91 &#177; 9</td><td align="center" valign="middle" >97 &#177; 3</td><td align="center" valign="middle" >96 &#177; 3</td></tr><tr><td align="center" valign="middle" >Ni</td><td align="center" valign="middle" >≥2.5</td><td align="center" valign="middle" >100 − 9</td><td align="center" valign="middle" >66 &#177; 8</td><td align="center" valign="middle" >74 &#177; 7</td></tr><tr><td align="center" valign="middle" >Zn</td><td align="center" valign="middle" >≤350</td><td align="center" valign="middle" >99 &#177; 1</td><td align="center" valign="middle" >93 &#177; 3</td><td align="center" valign="middle" >96 &#177; 2</td></tr></tbody></table></table-wrap><p>M―arithmetic mean, SD―standard deviation.</p><p>an acceptable accuracy of the results obtained in the study of trace elements of the prostate samples presented in <xref ref-type="table" rid="table1">Table 1</xref> and <xref ref-type="table" rid="table2">Table 2</xref>.</p><p>The mean values and all selected statistical parameters were calculated for 43 trace elements: Ag, Al, Au, B, Be, Bi, Br, Cd, Ce, Co, Cr, Cs, Dy, Er, Fe, Gd, Hg, Ho, La, Li, Mn, Mo, Nb, Nd, Ni, Pb, Pr, Rb, Sb, Sc, Se, Sm, Sn, Tb, Th, Ti, Tl, Tm, U, Y, Yb, Zn, and Zr trace element mass fractions (<xref ref-type="table" rid="table1">Table 1</xref>). The mass fraction of these trace elements were measured in all, or a major portion of normal prostate samples. The masses of BPH and PCa samples varied very strong from a few milligrams (sample from needle biopsy material) to 100 mg (sample from resected material). Therefore, in BPH and PCa prostates mass fractions of Ag, Br, Co, Cr, Fe, Hg, Rb, Sb, Sc, Se, and Zn were measured in all, or a major portion of samples, while mass fractions of other trace elements were determined in 22 samples (11 BPH and 11 PCa samples, respectively).</p><p>From <xref ref-type="table" rid="table2">Table 2</xref>, it is observed that in benign hypertrophic tissues the mass fractions of Ag, Al, Au, B, Be, Br, Cd, Co, Fe, Li, Mn, Nb, Ni, Rb, Sc, Th, Ti, Tl, Yb, Zn, and Zr not differ from normal levels, but the mass fractions of Bi, Cr, Hg, Sb, and Se are higher, while the mass fraction of Ce, Cs, Dy, Er, Gd, Ho, La, Mo, Nd, Pb, Pr, Sm, Sn, Tb, Tm, U, and Y are significantly lower. In cancerous tissue the mass fractions of Cd, Rb, Sc, Se, and Zn are significantly lower, and mass fractions of Ag, Al, Au, B, Be, Bi, Br, Cd, Ce, Cr, Dy, Er, Fe, Gd, Hg, Ho, Li, Mn, Nd, Ni, Pr, Sb, Sm, Sn, Tb, Th, Tl, Y, and Zr are significantly higher than in normal tissues of the prostate. All these trace elements show similar variations in cancerous tissues when compared with benign hypertrophic tissues of the prostate.</p><p>Analysis of the trace element mass fraction in prostate tissue could become a powerful diagnostic tool. To a large extent, the resumption of the search for new methods for early diagnosis of PCa was due to experience gained in a critical assessment of the limited capacity of the prostate specific antigen (PSA) serum test [<xref ref-type="bibr" rid="scirp.74050-ref72">72</xref>] . In addition to the PSA serum test and morphological study of needle-biopsy cores of the prostate, the development of other highly precise testing methods seems to be very useful.</p><p>Experimental conditions of the present study were approximated to the hospital conditions as closely as possible. In BPH and PCa cases we analyzed a part of the material obtained from a puncture transrectal biopsy of the indurated site in the prostate. Therefore, our data allow us to evaluate adequately the importance of trace element mass fraction for the diagnosis of PCa. As is evident from <xref ref-type="table" rid="table2">Table 2</xref> and, particularly, from individual data sets (<xref ref-type="fig" rid="fig1">Figure 1</xref>), the Ag, Al, B, Br, Li, Mn, Ni and Zn mass fraction are potentially the most informative test for a differential diagnosis. For example, if 4.0 mg/kg is the value of B mass fraction assumed to be the lower limit for PCa (<xref ref-type="fig" rid="fig1">Figure 1</xref>) and an estimation is made for “PCa or intact and BPH tissue”, the following values are obtained:</p><p>Sensitivity = {True Positives (TP)/[TP + False Negatives (FN)]}・100% = 90% &#177; 10%;</p><p>Specificity = {True Negatives (TN)/[TN + False Positives (FP)]}・100% = 100% − 3%;</p><p>Accuracy = [(TP + TN)/(TP + FP +TN + FN)]・100% = 98% &#177; 2%.</p><p>The number of people (samples) examined was taken into account for calculation of confidence intervals [<xref ref-type="bibr" rid="scirp.74050-ref73">73</xref>] . In other words, if B mass fraction in a prostate biopsy sample is higher than 4 mg/kg, one could diagnose a malignant tumor with an accuracy 98% &#177; 2%. Thus, using the B mass fraction-test makes it possible to diagnose cancer in 100% − 3%; cases (sensitivity). The same way parameters of the importance (sensitivity, specificity and accuracy) of Ag, Al, B, Br, Li, Mn, Ni and Zn mass fraction for the diagnosis of PCa were calculated (<xref ref-type="table" rid="table3">Table 3</xref>).</p></sec><sec id="s5"><title>5. Conclusions</title><p>The combination of nondestructive INAALSLR and destructive ICP-MS methods is satisfactory analytical tool for the precise determination of 43 trace element mass fractions in the tissue samples of normal, BPH and carcinomatous prostate glands. The sequential application of two methods allowed precise quantitative determinations of mean mass fraction of Ag, Al, Au, B, Be, Bi, Br, Cd, Ce, Co, Cr, Cs, Dy, Er, Fe, Gd, Hg, Ho, La, Li, Mn, Mo, Nb, Nd, Ni, Pb, Pr, Rb, Sb, Sc, Se, Sm, Sn, Tb, Th, Ti, Tl, Tm, U, Y, Yb, Zn and Zr. The mass fractions of all trace elements investigated in the study with the exception of La, Nb, and Yb show significant variations in cancerous tissues when compared with normal and BPH prostate. The contents of Rb, Sc, Se, and Zn were significantly lower and those of Ag, Al, Au, B, Be, Bi, Br, Ce, Cr, Dy, Er, Fe, Gd, Ho, Li, Mn, Nd, Ni, Pr, Sb, Sm, Sn, Tb, Th, Tl, Y, and Zr were significantly higher in cancerous tissues than in normal and BPH tissues. The Ag, Al, B, Br, Li, Mn, Ni and Zn mass fraction in a needle-biopsy core can be used as an accurate tool to diagnose prostate cancer. Further studies on larger number of samples are required to confirm our findings, to study the impact of the trace element contents on prostate cancer etiology.</p></sec><sec id="s6"><title>Acknowledgements</title><p>We are grateful to Dr. Tatyana Sviridova, Medical Radiological Research Center, Obninsk, and to the late Prof. A.A. Zhavoronkov, Institute of Human Morphology, Russian Academy of Medical Sciences, Moscow, for supplying prostate samples. We are also grateful to Dr. Karandaschev V., Dr. Nosenko S., and Moskvina I., Institute of Microelectronics Technology and High Purity Materials, Chernogolovka, Russia, for their help in ICP-MS analysis.</p></sec><sec id="s7"><title>Cite this paper</title><p>Zaichick, V. and Zaichick, S. (2017) Trace Element Levels in Prostate Gland as Carcinoma’s Markers. Journal of Cancer Therapy, 8, 131-145. https://doi.org/10.4236/jct.2017.82011</p></sec></body><back><ref-list><title>References</title><ref id="scirp.74050-ref1"><label>1</label><mixed-citation publication-type="book" xlink:type="simple">Roehrborn, C. and McConnell, J. (2002) Etiology, Pathophysiology, Epidemiology and Natural History of Benign Prostatic Hyperplasia. In: Walsh, P., Retik, A., Vaughan, E. and Wein, A., Eds., Campbell’s Urology, 8th ed., Saunders, Philadelphia, 1297-1336.</mixed-citation></ref><ref id="scirp.74050-ref2"><label>2</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Lepor</surname><given-names> H. </given-names></name>,<etal>et al</etal>. (<year>2005</year>)<article-title>Pathophysiology of Benign Prostatic Hyperplasia in the Aging Male Population</article-title><source> Reviews in Urology</source><volume> 7</volume>,<fpage> S3</fpage>-<lpage>S12</lpage>.<pub-id pub-id-type="doi"></pub-id></mixed-citation></ref><ref id="scirp.74050-ref3"><label>3</label><mixed-citation publication-type="other" xlink:type="simple">Oliver, S.E., Gunnell, D. and Donovan, J.L. (2000) Comparison of Trends in Prostate-Cancer Mortality in England and Wales and the USA. The Lancet, 355, 1788-1789. https://doi.org/10.1016/S0140-6736(00)02269-8</mixed-citation></ref><ref id="scirp.74050-ref4"><label>4</label><mixed-citation publication-type="other" xlink:type="simple">Kumar, R.J., Barqawi, A.B. and Crawford, E.D. (2004) Epidemiology of Prostate Cancer. Business Briefing: US Oncology Review, 1-6.</mixed-citation></ref><ref id="scirp.74050-ref5"><label>5</label><mixed-citation publication-type="other" xlink:type="simple">Maddams, J., Brewster, D., Gavin, A., Steward, J., Elliott, J., Utley, M. and Moller, H. (2009) Cancer Prevalence in the United Kingdom: Estimates for 2008. British Journal of Cancer, 101, 541-547. https://doi.org/10.1038/sj.bjc.6605148</mixed-citation></ref><ref id="scirp.74050-ref6"><label>6</label><mixed-citation publication-type="other" xlink:type="simple">Lutz, J.M., Francisci, S., Mugno, E., Usel, M., Pompe-Kirn, V., Coebergh, J.W., Bieslka-Lasota, M. and EUROPREVAL Working Group (2003) Cancer Prevalence in Central Europe: The EUROPREVAL Study. Annals of Oncology, 14, 313-322. 
https://doi.org/10.1093/annonc/mdg059</mixed-citation></ref><ref id="scirp.74050-ref7"><label>7</label><mixed-citation publication-type="other" xlink:type="simple">Moller, T., Anderson, H., Aareleid, T., Hakulinen, T., Storm, H., Tryggvadottir, L., Corazziari, I., Mugno, E. and EUROPREVAL Working Group (2003) Cancer Prevalence in Northern Europe: The EUROPREVAL Study. Annals of Oncology, 14, 946-957. https://doi.org/10.1093/annonc/mdg255</mixed-citation></ref><ref id="scirp.74050-ref8"><label>8</label><mixed-citation publication-type="other" xlink:type="simple">De Angelis, R., Grande, E., Inghelmann, R., Francisci, S., Micheli, A., Baili, P., Meneghini, E., Capocaccia, R. and Verdecchia, A. (2007) Cancer Prevalence Estimates in Italy from 1970 to 2010. Tumori, 93, 392-397.</mixed-citation></ref><ref id="scirp.74050-ref9"><label>9</label><mixed-citation publication-type="other" xlink:type="simple">Waalkes, M.P. and Rehm, S. (1994) Cadmium and Prostate Cancer. Journal of Toxicology and Environmental Health, 43, 251-269. 
https://doi.org/10.1080/15287399409531920</mixed-citation></ref><ref id="scirp.74050-ref10"><label>10</label><mixed-citation publication-type="other" xlink:type="simple">Zaichick, V. and Zaichick, S. (1999) Role of Zinc in Prostate Cancerogenesis. 19 Arbeitstagung on Mengen und Spurenelemente, Friedrich-Schiller-Universitat, Jena, 104-115.</mixed-citation></ref><ref id="scirp.74050-ref11"><label>11</label><mixed-citation publication-type="other" xlink:type="simple">Platz, E.A. and Helzlsouer, K.J. (2001) Selenium, Zinc, and Prostate Cancer. Epidemiologic Reviews, 23, 93-101.  
https://doi.org/10.1093/oxfordjournals.epirev.a000801</mixed-citation></ref><ref id="scirp.74050-ref12"><label>12</label><mixed-citation publication-type="other" xlink:type="simple">Zaichick, V. (2004) INAA and EDXRF Applications in the Age Dynamics Assessment of Zn Content and Distribution in the normal Human Prostate. Journal of Radioanalytical and Nuclear Chemistry, 262, 229-234.  
https://doi.org/10.1023/B:JRNC.0000040879.45030.4f</mixed-citation></ref><ref id="scirp.74050-ref13"><label>13</label><mixed-citation publication-type="other" xlink:type="simple">Gray, M.A., Centeno, J.A., Slaney, D.P., Ejnik, J.W., Todorov, T. and Nacey, J.N. (2005) Environmental Exposure to Trace Elements and Prostate Cancer in Three New Zealand Ethnic Groups. International Journal of Environmental Research and Public Health, 2, 374-384. https://doi.org/10.3390/ijerph2005030001</mixed-citation></ref><ref id="scirp.74050-ref14"><label>14</label><mixed-citation publication-type="other" xlink:type="simple">Zaichick, S. and Zaichick, V. (2011) INAA Application in the Age Dynamics Assessment of Br, Ca, Cl, K, Mg, Mn, and Na Content in the Normal Human Prostate. Journal of Radioanalytical and Nuclear Chemistry, 288, 197-202.  
https://doi.org/10.1007/s10967-010-0927-4</mixed-citation></ref><ref id="scirp.74050-ref15"><label>15</label><mixed-citation publication-type="other" xlink:type="simple">Zaichick, S. and Zaichick, V. (2011) The Effect of Age on Ag, Co, Cr, Fe, Hg, Sb, Sc, Se, and Zn Contents in Intact Human Prostate Investigated by Neutron Activation Analysis. Applied Radiation and Isotopes, 69, 827-833.  
https://doi.org/10.1016/j.apradiso.2011.02.010</mixed-citation></ref><ref id="scirp.74050-ref16"><label>16</label><mixed-citation publication-type="other" xlink:type="simple">Zaichick, S. and Zaichick, V. (2011) The Br, Fe, Rb, Sr, and Zn Content and Interrelation in Intact and Morphologic Normal Prostate Tissue of Adult Men Investigated by Energy Dispersive X-Ray Fluorescent Analysis. X-Ray Spectrometry, 40, 464-469. https://doi.org/10.1002/xrs.1370</mixed-citation></ref><ref id="scirp.74050-ref17"><label>17</label><mixed-citation publication-type="other" xlink:type="simple">Zaichick, V., Nosenko, S. and Moskvina, I. (2012) The Effect of Age on 12 Chemical Element Contents in Intact Prostate of Adult Men Investigated by Inductively Coupled Plasma Atomic Emission Spectrometry. Biological Trace Element Research, 147, 49-58. https://doi.org/10.1007/s12011-011-9294-4</mixed-citation></ref><ref id="scirp.74050-ref18"><label>18</label><mixed-citation publication-type="other" xlink:type="simple">Zaichick, S., Zaichick, V., Nosenko, S. and Moskvina, I. (2012) Mass fractions of 52 Trace Elements and Zinc Trace Element Content Ratios in Intact Human Prostates Investigated by Inductively Coupled Plasma Mass Spectrometry. Biological Trace Element Research, 149, 171-183. https://doi.org/10.1007/s12011-012-9427-4</mixed-citation></ref><ref id="scirp.74050-ref19"><label>19</label><mixed-citation publication-type="other" xlink:type="simple">Zaichick, V. and Zaichick, S. (2014) Age-Related Histological and Zinc Content Changes in Adult Nonhyperplastic Prostate Glands. Age, 36, 167-181.  
https://doi.org/10.1007/s11357-013-9561-8</mixed-citation></ref><ref id="scirp.74050-ref20"><label>20</label><mixed-citation publication-type="other" xlink:type="simple">Zaichick, V. and Zaichick, S. (2014) INAA Application in the Assessment of Chemical Element Mass Fractions in Adult and Geriatric Prostate Glands. Applied Radiation and Isotopes, 90, 62-73. https://doi.org/10.1016/j.apradiso.2014.03.010</mixed-citation></ref><ref id="scirp.74050-ref21"><label>21</label><mixed-citation publication-type="other" xlink:type="simple">Zaichick, V. and Zaichick, S. (2014) Determination of Trace Elements in Adults and Geriatric Prostate Combining Neutron Activation with Inductively Coupled Plasma Atomic Emission Spectrometry. Open Journal of Biochemistry, 1, 16-33.</mixed-citation></ref><ref id="scirp.74050-ref22"><label>22</label><mixed-citation publication-type="other" xlink:type="simple">Zaichick, V. and Zaichick, S. (2014) Use of INAA and ICP-MS for the Assessment of Trace Element Mass Fractions in Adult and Geriatric Prostate. Journal of Radioanalytical and Nuclear Chemistry, 301, 383-397.  
https://doi.org/10.1007/s10967-014-3173-3</mixed-citation></ref><ref id="scirp.74050-ref23"><label>23</label><mixed-citation publication-type="other" xlink:type="simple">Zaichick, V. (2015) The Variation with Age of 67 Macro- and Microelement Contents in Nonhyperplastic Prostate Glands of Adult and Elderly Males Investigated by Nuclear Analytical and Related Methods. Biological Trace Element Research, 168, 44-60. https://doi.org/10.1007/s12011-015-0342-3</mixed-citation></ref><ref id="scirp.74050-ref24"><label>24</label><mixed-citation publication-type="other" xlink:type="simple">Zaichick, V. and Zaichick, S. (2015) Dietary Intake of Minerals and Prostate Cancer: Insights into Problem Based on the Chemical Element Contents in the Prostate Gland. Journal of Aging Research and Clinical Practice, 4, 164-171.</mixed-citation></ref><ref id="scirp.74050-ref25"><label>25</label><mixed-citation publication-type="other" xlink:type="simple">Zaichick, V. and Zaichick, S. (2015) Global Contamination from Uranium: Insights into Problem Based on the Uranium Content in the Human Prostate Gland. Journal of Environmental Health Science, 1, 1-5.</mixed-citation></ref><ref id="scirp.74050-ref26"><label>26</label><mixed-citation publication-type="other" xlink:type="simple">Zaichick, V. and Zaichick, S. (2016) Variations in Concentration and Distribution of Several Androgen-Dependent and -Independent Trace Elements in Nonhyperplastic Prostate Gland Tissue Throughout Adulthood. Journal of Andrology and Gynaecology, 4, 1-10.</mixed-citation></ref><ref id="scirp.74050-ref27"><label>27</label><mixed-citation publication-type="other" xlink:type="simple">Zaichick, V. and Zaichick, S. (2016) Age-Related Changes in Concentration and Histological Distribution of Br, Ca, Cl, K, Mg, Mn, and Na in Nonhyperplastic Prostate of Adults. European Journal of Biology and Medical Science Research, 4, 31-48.</mixed-citation></ref><ref id="scirp.74050-ref28"><label>28</label><mixed-citation publication-type="other" xlink:type="simple">Zaichick, V. and Zaichick, S. (2016) Variations in Concentration and Histological Distribution of Ag, Co, Cr, Fe, Hg, Rb, Sb, Sc, Se, and Zn in Nonhyperplastic Prostate Gland Throughout Adulthood. Jacobs Journal of Cell and Molecular Biology, 2, 011.</mixed-citation></ref><ref id="scirp.74050-ref29"><label>29</label><mixed-citation publication-type="other" xlink:type="simple">Zaichick, V. and Zaichick, S. (2016) Age-Related Changes in Concentration and Histological Distribution of 54 Trace Elements in Nonhyperplastic Prostate of Adults. International Archives of Urology and Complications, 2,019.  
https://doi.org/10.23937/2469-5742/1510019</mixed-citation></ref><ref id="scirp.74050-ref30"><label>30</label><mixed-citation publication-type="other" xlink:type="simple">Zaichick, V. (2006) Medical Elementology as a New Scientific Discipline. Journal of Radioanalytical and Nuclear Chemistry, 269, 303-309.  
https://doi.org/10.1007/s10967-006-0383-3</mixed-citation></ref><ref id="scirp.74050-ref31"><label>31</label><mixed-citation publication-type="other" xlink:type="simple">Stitch, S.R. (1957) Trace Elements in Human Tissue. I: A Semi-Quantitative Spectrographic Survey. Biochemistry Journal, 67, 97-103.  
https://doi.org/10.1042/bj0670097</mixed-citation></ref><ref id="scirp.74050-ref32"><label>32</label><mixed-citation publication-type="other" xlink:type="simple">Tipton, J.H. and Cook, M.J. (1963) Trace Elements in Human Tissue. Part II. Adult Subjects from the United States. Health Physics, 9, 103-145.  
https://doi.org/10.1097/00004032-196302000-00002</mixed-citation></ref><ref id="scirp.74050-ref33"><label>33</label><mixed-citation publication-type="other" xlink:type="simple">Gyorkey, F., Min, K.-W., Huff, J.A. and Gyorkey, P. (1967) Zinc and Magnesium in Human Prostate Gland: Normal, Hyperplastic, and Neoplastic. Cancer Research, 27, 1349-1353.</mixed-citation></ref><ref id="scirp.74050-ref34"><label>34</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Sangen</surname><given-names> H. </given-names></name>,<etal>et al</etal>. (<year>1967</year>)<article-title>The Influence of the Trace Metals upon the Aconitase Activity in Human Prostate Glands</article-title><source> Japanese Journal of Urology</source><volume> 58</volume>,<fpage> 1146</fpage>-<lpage>1159</lpage>.<pub-id pub-id-type="doi"></pub-id></mixed-citation></ref><ref id="scirp.74050-ref35"><label>35</label><mixed-citation publication-type="other" xlink:type="simple">Schneider, H.-J., Anke, M. and Holm, W. (1970) The Inorganic Components of Testicle, Epididymis, Seminal Vesicle, Prostate and Ejaculate of Young Men. International Urology and Nephrology, 2, 419-427. https://doi.org/10.1007/BF02081698</mixed-citation></ref><ref id="scirp.74050-ref36"><label>36</label><mixed-citation publication-type="other" xlink:type="simple">Hienzsch, E., Schneider, H.-J. and Anke, M. (1970) Vergleichende Untersuchungen zum Mengenund Spurenelementgehalt der normalen Prostata, des Prostataadenoms und des Prostatakarzinoms. Zeitschrift für Urologie und Nephrologie, 63, 543-546.</mixed-citation></ref><ref id="scirp.74050-ref37"><label>37</label><mixed-citation publication-type="other" xlink:type="simple">Soman, S.D., Joseph, K.T., Raut, S.J., Mulay, G.D., Parameswaran, M. and Pandey, V.K. (1970) Studies of Major and Trace Element Content in Human Tissues. Health Physics, 19, 641-656. https://doi.org/10.1097/00004032-197011000-00006</mixed-citation></ref><ref id="scirp.74050-ref38"><label>38</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Forssen</surname><given-names> A. </given-names></name>,<etal>et al</etal>. (<year>1972</year>)<article-title>Inorganic Elements in the Human Body. I. Occurrence of Ba, Br, Ca, Cd, Cs, Cu, K, Mn, Ni, Sn, Sr, Y and Zn in the Human Body</article-title><source> Annales Medicinae Experimentalis et Biologie</source><volume> 50</volume>,<fpage> 99</fpage>-<lpage>162</lpage>.<pub-id pub-id-type="doi"></pub-id></mixed-citation></ref><ref id="scirp.74050-ref39"><label>39</label><mixed-citation publication-type="other" xlink:type="simple">Dhar, N.K., Goel, T.C., Dube, P.C., Chowdhury, A.R. and Kar, A.B. (1973) Distribution and Concentration of Zinc in the Subcellular Fractions of Benign Hyperplastic and Malignant Neoplastic Human Prostate. Experimental and Molecular Pathology, 19, 139-142. https://doi.org/10.1016/0014-4800(73)90073-7</mixed-citation></ref><ref id="scirp.74050-ref40"><label>40</label><mixed-citation publication-type="other" xlink:type="simple">Jafa, A., Mahendra, N.M., Chowdhury, A.R. and Kamboj, V.P. (1980) Trace Elements in Prostatic Tissue and Plasma in Prostatic Diseases of Man. Indian Journal of Cancer, 17, 34-37.</mixed-citation></ref><ref id="scirp.74050-ref41"><label>41</label><mixed-citation publication-type="other" xlink:type="simple">Marezynska, A., Kulpa, J. and Lenko, J. (1983) The Concentration of Zinc in Relation to Fundamental Elements in the Diseases Human Prostate. International Urology and Nephrology, 15, 257-265. https://doi.org/10.1007/BF02083012</mixed-citation></ref><ref id="scirp.74050-ref42"><label>42</label><mixed-citation publication-type="book" xlink:type="simple">Hienzsch, E., Schneider, H.-J., Anke, M., Hennig, A. and Groppel, B. (1979) The Cadmium-, Zinc-, Copper-, and Managanese-Level of Different Organs of Human Beings without Considerable Cd-Exposure Independence on Age and Sex. In: Anke, M. and Schneider, H.-J., Eds., Kadmiumsymposium, Wissenschaftliche Beitrage der Friedrich-Schiller-Universitat, Jena, 276-282.</mixed-citation></ref><ref id="scirp.74050-ref43"><label>43</label><mixed-citation publication-type="other" xlink:type="simple">Picurelli, L., Olcina, P.V., Roig, M.D. and Ferrer, J. (1991) Determination of Fe, Mg, Cu, and Zn in Normal and Pathological Prostatic Tissue. Actas Urológicas Espanolas, 15, 344-350.</mixed-citation></ref><ref id="scirp.74050-ref44"><label>44</label><mixed-citation publication-type="other" xlink:type="simple">Galván-Bobadilla, A.I., García-Escamilla, R.M., Gutiérrez-García, N., Mendoza-Magana, M.L. and Rosiles-Martínez, R. (2005) Cadmium and Zinc Concentrations in Prostate Cancer and Benign Prostate Hyperplasia. Revista Latinoamericana de Patología Clínica, 52, 109-117.</mixed-citation></ref><ref id="scirp.74050-ref45"><label>45</label><mixed-citation publication-type="other" xlink:type="simple">Yaman, M., Atici, D., Bakirdere, S. and Akdeniz, I. (2005) Comparison of Trace Metal Concentrations in Malignant and Benign Human Prostate. Journal of Medicinal Chemistry, 48, 630-634. https://doi.org/10.1021/jm0494568</mixed-citation></ref><ref id="scirp.74050-ref46"><label>46</label><mixed-citation publication-type="other" xlink:type="simple">Kwiatek, W.M., Banas, A., Banas, K., Podgorczyk, M., Dyduch, G., Falkenberg, G., Gajda, M. and Cichocki T. (2006) Distinguishing Prostate Cancer from Hyperplasia. Acta Physica Polonica, 109, 377-381. https://doi.org/10.12693/APhysPolA.109.377</mixed-citation></ref><ref id="scirp.74050-ref47"><label>47</label><mixed-citation publication-type="other" xlink:type="simple">Guntupalli, J.N.R., Sarita, P., Ramana Murty, G.A.V., Ravi Kumar, M., Seetharami Reddy, B., Lakshminarayana, S., Prema Chand, K., Durga Prasad, A., Bhuloka Reddy, S., Vijayan, V., Rama Lakshmi, P.V.B. and Satyanarayana, G. (2007) Trace Elemental Analysis of Normal, Benign Hypertrophic and Cancerous Tissues of the Prostate Gland Using the Particle-Induced X-Ray Emission Technique. European Journal of Cancer Prevention, 16, 108-115.  
https://doi.org/10.1097/01.cej.0000228409.75976.b6</mixed-citation></ref><ref id="scirp.74050-ref48"><label>48</label><mixed-citation publication-type="other" xlink:type="simple">Tohno, S., Kobayashi, M., Shimizu, H., Tohno, Y., Suwannahoy, P., Azuma, C., Minami, T., Sinthubua, A. and Mahakkanukrauh P. (2009) Age-Related Changes of the Concentrations of Select Elements in the Prostates of Japanese. Biological Trace Element Research, 127, 211-227. https://doi.org/10.1007/s12011-008-8241-5</mixed-citation></ref><ref id="scirp.74050-ref49"><label>49</label><mixed-citation publication-type="other" xlink:type="simple">Kiziler, A.R., Aydemir, B., Guzel, S., Alici, B., Ataus, S., Tuna, M.B., Durak, H. And Kilic, M. (2010) May the Level and Ratio Changes of Trace Elements Be Utilized in Identification of Disease Progression and Grade in Prostatic Cancer? Trace Elements and Electrolytes, 27, 65-72. https://doi.org/10.5414/TEP27065</mixed-citation></ref><ref id="scirp.74050-ref50"><label>50</label><mixed-citation publication-type="other" xlink:type="simple">Zaichick, S. and Zaichick, V. (2010) Method and Portable Facility for Energy-Dispersive X-Ray Fluorescent Analysis of Zinc Content in Needle-Biopsy Specimens of Prostate. X-Ray Spectrometry, 39, 83-89. https://doi.org/10.1002/xrs.1233</mixed-citation></ref><ref id="scirp.74050-ref51"><label>51</label><mixed-citation publication-type="other" xlink:type="simple">Zaichick, V. and Zaichick, S. (2013) The Effect of Age on Br, Ca, Cl, K, Mg, Mn, and Na Mass Fraction in Pediatric and Young Adult Prostate Glands Investigated by Neutron Activation Analysis. Applied Radiation and Isotopes, 82, 145-151.  
https://doi.org/10.1016/j.apradiso.2013.07.035</mixed-citation></ref><ref id="scirp.74050-ref52"><label>52</label><mixed-citation publication-type="other" xlink:type="simple">Zaichick, V. and Zaichick, S. (2013) NAA-SLR and ICP-AES Application in the Assessment of Mass Fraction of 19 Chemical Elements in Pediatric and Young Adult Prostate Glands. Biological Trace Element Research, 156, 357-366.  
https://doi.org/10.1007/s12011-013-9826-1</mixed-citation></ref><ref id="scirp.74050-ref53"><label>53</label><mixed-citation publication-type="other" xlink:type="simple">Leitao, R.G., Palumbo, A., Souza, P.A.V.R., Pereira, G.R., Canellas, C.G.L., Anjos, M.J. and Nasciutti, L.E. (2014) Elemental Concentration Analysis in Prostate Tissues Using Total Reflection X-Ray Fluorescence. Radiation Physics and Chemistry, 95, 62-64. https://doi.org/10.1016/j.radphyschem.2012.12.044</mixed-citation></ref><ref id="scirp.74050-ref54"><label>54</label><mixed-citation publication-type="book" xlink:type="simple">Zaichick, S. and Zaichick, V. (2014) EDXRF Determination of Trace Element Contents in Benign Prostatic Hypertrophic Tissue. In: Frank, I.M. and Shapiro, F.L., Eds., Fundamental Interactions and Neutrons, Neutron Spectroscopy, Nuclear Structure, Ultracold Neutrons, Related Topics, Joint Institute for Nuclear Research, Dubna, 311-316.</mixed-citation></ref><ref id="scirp.74050-ref55"><label>55</label><mixed-citation publication-type="other" xlink:type="simple">Denoyer, D., Clatworthy, S.A.S., Masaldan, S., Meggyesy, P.M. and Cater, M.A. (2015) Heterogeneous Copper Concentrations in Cancerous Human Prostate Tissues. Prostate, 75, 1510-1517. https://doi.org/10.1002/pros.23022</mixed-citation></ref><ref id="scirp.74050-ref56"><label>56</label><mixed-citation publication-type="other" xlink:type="simple">Zaichick, S. and Zaichick, V. (2015) Prostatic Tissue Level of Some Androgen Dependent and Independent Trace Elements in Patients with Benign Prostatic Hyperplasia. Andrology and Gynecology: Current Research, 3, 3.  
https://doi.org/10.4172/2327-4360.1000141</mixed-citation></ref><ref id="scirp.74050-ref57"><label>57</label><mixed-citation publication-type="other" xlink:type="simple">Singh, B.P., Dwivedi, S., Dhakad, U., Murthy, R.C., Choubey, V.K., Goel, A. and Sankhwar, S.N. (2016) Status and Interrelationship of Zinc, Copper, Iron, Calcium and Selenium in Prostate Cancer. Indian Journal of Clinical Biochemistry, 31, 50-56. https://doi.org/10.1007/s12291-015-0497-x</mixed-citation></ref><ref id="scirp.74050-ref58"><label>58</label><mixed-citation publication-type="other" xlink:type="simple">Zaichick, V. and Zaichick, S. (2016) Trace Element Contents in Adenocarcinoma of Human Prostate Investigated by Energy Dispersive X-Ray Fluorescent Analysis. Journal of Adenocarcinoma, 1, 1-7.</mixed-citation></ref><ref id="scirp.74050-ref59"><label>59</label><mixed-citation publication-type="other" xlink:type="simple">Zaichick, V. and Zaichick, S. (2016) The Bromine, Calcium, Potassium, Magnesium, Manganese, and Sodium Contents in Adenocarcinoma of Human Prostate Gland. Journal of Hematology and Oncology Research, 2, 1-12.  
https://doi.org/10.14302/issn.2372-6601.jhor-15-896</mixed-citation></ref><ref id="scirp.74050-ref60"><label>60</label><mixed-citation publication-type="other" xlink:type="simple">Zaichick, V. and Zaichick, S. (2016) Trace Element Contents in Adenocarcinoma of the Human Prostate Gland Investigated by Neutron Activation Analysis. Cancer Research and Oncology, 1, 1-10.</mixed-citation></ref><ref id="scirp.74050-ref61"><label>61</label><mixed-citation publication-type="other" xlink:type="simple">Zaichick, V. and Zaichick, S. (2016) Prostatic Tissue Levels of 43 Trace Elements in Patients with Prostate Adenocarcinoma. Cancer and Clinical Oncology, 5, 79-94.  
https://doi.org/10.5539/cco.v5n1p79</mixed-citation></ref><ref id="scirp.74050-ref62"><label>62</label><mixed-citation publication-type="other" xlink:type="simple">Zaichick, V. and Zaichick, S. (2016) Prostatic Tissue Level of Some Major and Trace Elements in Patients with BPH. Jacobs Journal of Nephrology and Urology, 3, 026.</mixed-citation></ref><ref id="scirp.74050-ref63"><label>63</label><mixed-citation publication-type="other" xlink:type="simple">Zaichick, V. and Zaichick, S. (2016) Levels of 43 Trace Elements in Hyperplastic Prostate Tissues. British Journal of Medicine and Medical Research, 15, 1-12.  
https://doi.org/10.9734/BJMMR/2016/25275</mixed-citation></ref><ref id="scirp.74050-ref64"><label>64</label><mixed-citation publication-type="other" xlink:type="simple">Zaichick, V. and Zaichick, S. (2016) Chemical Elemental Content/Calcium Ratios in Tissues of Human Hyperplastic Prostate Gland. Journal of Applied Life Sciences International, 4, 1-11. https://doi.org/10.9734/JALSI/2016/24747</mixed-citation></ref><ref id="scirp.74050-ref65"><label>65</label><mixed-citation publication-type="other" xlink:type="simple">Zaichick, V., Sviridova, T. and Zaichick, S. (1997) Zinc in Human Prostate Gland: Normal, Hyperplastic and Cancerous. International Urology and Nephrology, 29, 565-574. https://doi.org/10.1007/BF02552202</mixed-citation></ref><ref id="scirp.74050-ref66"><label>66</label><mixed-citation publication-type="other" xlink:type="simple">Zaichick, S. and Zaichick, V. (2012) Trace Elements of Normal, Benign Hypertrophic and Cancerous Tissues of the Human Prostate Gland Investigated by Neutron Activation Analysis. Applied Radiation and Isotopes, 70, 81-87.  
https://doi.org/10.1016/j.apradiso.2011.08.021</mixed-citation></ref><ref id="scirp.74050-ref67"><label>67</label><mixed-citation publication-type="book" xlink:type="simple">Zaichick, V. (1997) Sampling, Sample Storage and Preparation of Biomaterials for INAA in Clinical Medicine, Occupational and Environmental Health. In: IAEA, Ed., Harmonization of Health-Related Environmental Measurements Using Nuclear and Isotopic Techniques, IAEA, Vienna, 123-133.</mixed-citation></ref><ref id="scirp.74050-ref68"><label>68</label><mixed-citation publication-type="other" xlink:type="simple">Zaichick, V. and Zaichick, S. (1996) Instrumental Effect on the Contamination of Biomedical Samples in the Course of Sampling. The Journal of Analytical Chemistry, 51, 1200-1205. (In Russian)</mixed-citation></ref><ref id="scirp.74050-ref69"><label>69</label><mixed-citation publication-type="other" xlink:type="simple">Zaichick, V. and Zaichick, S. (1997) A Search for Losses of Chemical Elements during Freeze-Drying of Biological Materials. Journal of Radioanalytical and Nuclear Chemistry, 218, 249-253. https://doi.org/10.1007/BF02039345</mixed-citation></ref><ref id="scirp.74050-ref70"><label>70</label><mixed-citation publication-type="journal" xlink:type="simple"><name name-style="western"><surname>Zaichick</surname><given-names> V. </given-names></name>,<etal>et al</etal>. (<year>2004</year>)<article-title>Losses of Chemical Elements in Biological Samples under the Dry Aching Process</article-title><source> Trace Elements in Medicine</source><volume> 5</volume>,<fpage> 17</fpage>-<lpage>22</lpage>.<pub-id pub-id-type="doi"></pub-id></mixed-citation></ref><ref id="scirp.74050-ref71"><label>71</label><mixed-citation publication-type="book" xlink:type="simple">Korelo, A.M. and Zaichick, V. (1993) Software to Optimize the Multielement INAA of Medical and Environmental Samples. In: Nazarov, V.M., Ed., Activation Analysis in Environment Protection, Joint Institute for Nuclear Research, Dubna, 326-332. (In Russian)</mixed-citation></ref><ref id="scirp.74050-ref72"><label>72</label><mixed-citation publication-type="other" xlink:type="simple">Catalona, W.J. (1996) Clinical Utility of Measurements of Free and Total Prostate-Specific Antigen (PSA): A Review. Prostate, 29, 64-69.  
https://doi.org/10.1002/(SICI)1097-0045(1996)7+&lt;64::AID-PROS9&gt;3.0.CO;2-J</mixed-citation></ref><ref id="scirp.74050-ref73"><label>73</label><mixed-citation publication-type="other" xlink:type="simple">Genes V.S. (1967) Simple Methods for Cybernetic Data Treatment of Diagnostic and Physiological Studies. Nauka, Moscow, 208 p. (In Russian)</mixed-citation></ref></ref-list></back></article>