Ovarian cancer is one of the most malignant gynecological cancers, which is often at later stages (FIGO) with peritoneal dissemination [1]. Ovarian cancer remains one of the leading causes of death from gynecologic cancers in China [2]. Over 70% of patients are FIGO stage III-IV, which have poor long-term survival [3]. This is the reason why late-stage ovarian cancer has high rates of recurrence and poor long-term survival [4]. The most important predictive factor for death in advanced ovarian cancer [5] is cytoreductive surgery for complete macroscopic tumor removal (CC-0). The Peritoneal Cancer Index (PCI) is a system that is widely used to evaluate intraperitoneal tumour burden (scale 0 - 39) and to guide surgical management [6].

Hyperthermic intraperitoneal chemotherapy (HIPEC) combines intraoperative heated chemotherapy and cytoreduction to increase the local distribution of the drugs and may overcome platinum resistance mechanisms by hyperthermia-enhanced drug cytotoxicity [7][8].

High-grade serous carcinoma (HGSC), which is the most common histological type of serous carcinoma, has a fast course, high recurrence rates, and early dissemination in the peritoneum [9]. The standard treatment is cytoreductive surgery (CRS) & chemotherapy (platinum) and the use of neoadjuvant chemotherapy has increased in those with a high disease burden [10][11]. The combination of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy is a complex combination of treatment that must be carefully planned and patiently decided upon, depending on the patient; it requires specialist surgical skills, standardisation of chemotherapy administration, and multidisciplinary perioperative management. They may differ depending on the stage of the disease, the size of the tumour, histopathology, platinum sensitivity, past chemotherapy, institutional protocols and the chances of attaining satisfactory cytoreduction [12][13].

While there have been studies of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC) in other countries, there is limited detail at an institutional level from individual geographic centres. The explanation of patient selection, disease characteristics, chemotherapy use, treatment setting, Peritoneal Cancer Index, and the completeness of cytoreduction can assist in local clinical audit and give the initial evidence for future outcome studies.

The aim of this study was thus to outline the demographic, disease and treatment parameters in patients with advanced ovarian or primary peritoneal carcinoma undergoing hyperthermic intraperitoneal chemotherapy (HIPEC) at a single ovarian cancer specialist centre [14][15].

Most patients presented with advanced FIGO stage III disease, predominantly stage IIIC, and ovarian origin was the most common tumor site Table 1.

Table 1. Disease characteristics of the study population.

The continuous clinical characteristics were also analysed in order to describe the age distribution and extent of the disease in the peritoneum in the cohort. The mean, standard deviation, and observed range is used to summarise patients age and the Peritoneal Cancer Index. Histopathological and treatment characteristics are represented in Table 2. These are measures to give more background information about the demography profile and intra-abdominal tumour burden of patients who were chosen for CRS-HIPEC. Continuous clinical characteristics shown in Table 3.

Table 2. Histopathological and treatment characteristics.

Table 3. Continuous clinical characteristics.

This is a retrospective, single center study that characterizes the disease and treatment of 40 patients with advanced ovarian or primary peritoneal cancer receiving cytoreductive surgery and hyperthermic intraperitoneal chemotherapy. The majority of patients presented with FIGO stage III disease, ovarian primary tumours and serous histology. Over a half of the patients were treated with neoadjuvant chemotherapy, the most common treatment category was primary cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy [18][19].

The most common high grade histopathological subgroup was serous carcinoma (42.5%). However, the study population was diverse and included both clear-cell and endometrioid, low-grade serous, mucinous and undifferentiated carcinomas. The histological heterogeneity should be taken into account when interpreting the cohort as there may be differences in the biological behaviour, platinum-based chemotherapy response and treatment pathways.

Complete macroscopic cytoreduction (CC-0) was achieved in 50.0% of patients, while 95.0% had CC-0 or CC-1 residual-disease status. The CC-score distribution is an important operative characteristic in advanced ovarian cancer; however, its association with progression-free or overall survival was not assessed in this study, and thus could not be related to progression-free or overall survival. Low mean Peritoneal Cancer Index and the high combined rate of CC-0 and CC-1 cytoreduction may also be due to careful patient selection for the extensive cytoreduction surgery [20].

There were various types of treatment settings represented, such as primary disease, interval surgery following neoadjuvant chemotherapy, platinum-sensitive recurrence, and platinum-resistant recurrence. All of the various clinical settings extend the descriptive range of the study, but they also make for treatment heterogeneity. The three reported hyperthermic intraperitoneal chemotherapy (HIPEC) regimens were also found, suggesting that there was not a standard approach throughout the cohort. The differences do not permit direct comparisons to be made between treatment categories.

The study offers institution-specific data in a regional centre where there are only limited published data on patient selection and operative characteristics. But there was no standardized information about surgical complications in the available analytical data. Thus, the study is unable to measure the incidence or severity of postoperative morbidity, nor is it able to determine the safety or feasibility of cytoreductive surgery and hyperthermic intraperitoneal chemotherapy or to determine comparative effectiveness.

The results should therefore be considered as descriptive rather than confirmatory, and hypothesis generating. The collection of standardized postoperative outcomes, such as Clavien-Dindo grade, the type of complication, acute kidney injury, hematological toxicity, intensive-care admission, reoperation, readmission, length of hospital stay, and mortality at 30 and 90 days, should be collected in future studies in a prospective manner. Additional multicentre study cohorts would also allow for adjustment for age, comorbidity, Peritoneal Cancer Index, complexity of operation, chemotherapy regimen and completeness of cytoreduction.

This is a retrospective, single-center study of 40 patients who received cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC) for advanced ovarian or primary peritoneal cancer (PP). The majority of patients presented with FIGO stage III disease and high-grade serous carcinoma was the most common histological type. Cytoreduction was successful (CC-0 or CC-1) in 95.0% of the patients. Due to lack of standardized patient-level postoperative complication data, no conclusions can be drawn about postoperative morbidity, safety, comparative effectiveness or survival. Standardization of the collection of outcomes and larger multicenter samples are needed for prospective studies.

There are a number of significant limitations to this study. This was a retrospective study and thus suffered from incomplete documentation, inconsistent documentation, information bias and residual selection bias. The study was limited to a single centre, with a small number of patients (only 40), which reduced the generalisability and statistical power of the study. Several treatment settings and hyperthermic intraperitoneal chemotherapy regimens as well as histological subtypes were included in the cohort, leading to high clinical heterogeneity. A comparison group for non-HIPEC was not available. Most importantly, the analytical dataset was not standardized to provide information on patient level postoperative complications, which would allow estimation of morbidity, Clavien-Dindo grade, treatment-related toxicity, reoperation, readmission, postoperative mortality, and factors associated with adverse outcomes. Not evaluated: Recurrence-free survival and overall survival.

The study received approval from the Ethics Committee of Xuzhou Second Affiliated Hospital, China (XYFY2023-KL107-01). Subjects were reviewed anonymously for research purposes, and informed consent was waived per institutional policy, due to the retrospective design of this study.

Ishfaq Beenish conceptualized, curated data, performed formal analysis and undertook writing: original draft. Chen Buze participated in the supervision, validation and writing: review & editing. The manuscript was read and approved by all authors.

Patient privacy concerns mean that the datasets analyzed and/or generated during the current study are not publicly available, but they may be made available to the corresponding author on reasonable request.

The authors would like to thank the clinical, nursing and medical records staff for their assistance in providing patient care and retrieval of the data for this study.