TITLE:
Detection of HER-2/neu Amplification on Fine Needle Aspirates of Breast Cancer Using Fluorescence in Situ Hybridization
AUTHORS:
Talaat Iman, Sorour Amani, Abdel-Hadi Mona
KEYWORDS:
Breast Cancer; FISH on FNA; Immunohistochemistry; HER-2/neu
JOURNAL NAME:
Journal of Cancer Therapy,
Vol.4 No.7A,
July
22,
2013
ABSTRACT: The accuracy of diagnostic assays for
HER-2/neu in breast cancer is extremely important as HER-2/neu status is essential in tailoring adjuvant and/or neoadjuvant treatment in every
patient. FNAC is widely practiced in Egypt in preoperative diagnosis of breast cancer for
its low cost and high diagnostic accuracy. Since the determination of HER-2/neu
protein expression on cytological preparations was previously found to be
unreliable for clinical use, we opted for the assessment of HER-2/neu status in
fine needle aspirates using FISH. The main objective of this study was to
evaluate the reliability of HER-2/neu status assessment by FISH on fine needle
aspirates of breast cancers by comparing the results with IHC and FISH on FFPE tissue
sections obtained from corresponding surgically resected specimens. Fine needle aspirates from 40 breast cancer
patients with pathologically confirmed breast cancer were included in the
study. They were submitted for HER-2/neu evaluation by FISH. After surgery, the
corresponding FFPE sections were evaluated for HER-2/neu by FISH and by IHC. FNAs from 11 cases proved to be
amplified by FISH, while 29 cases were not amplified. Apart from two cases that
showed lack of signals, all specimens evaluated by FISH on the corresponding
FFPE sections showed matched results. The Measurement of Agreement between FISH
on FNAs and FISH on FFPE sections was 86.7%, while that between FISH on FNAs
and IHC was 72.5%. The high concordance rate in the present study between FISH
evaluation of HER-2/neu gene amplification on FNAC samples and their corresponding
FFPE samples indicate that FISH may be a reliable technique for HER-2/neu
assessment on FNAs. Furthermore, FISH on FNAs gave us better hybridization
signals than their corresponding FFPE tissue sections. Finally, we also
conclude that all score (2+) cases by IHC should be reevaluated by FISH which
is crucial for the patient management.