The use of ovarian cancer cells from patients undergoing surgery to generate primary cultures capable of undergoing functional analysis.

The use of cell lines or animal models has significant disadvantages when dealing with a set of heterogeneous diseases such as epithelial ovarian cancer. This has clinical relevance in that biomarkers developed using cell line or animal models are often not transferable to the clinical setting. In this study, we describe the development of a robust protocol for developing primary cultures of ovarian cancer which will overcome some of these difficulties. Women undergoing surgery for ovarian cancer were recruited and samples of ascites and solid tumour deposits were used to develop primary cultures. Cells were characterised using a panel of immunofluorescent antibodies prior to use in a variety of assays including functional assessment of DNA repair pathways. During the four year study period, viable cultures, confirmed to be epithelial in origin were generated from 156 of 172 (91%) cases recruited. Characterisation was carried out using a panel of antibodies including pancytokeratin, CA125, EpCAM, MOC-31, D2-40 and vimentin. Senescence occurred between the 2nd and 8th passages in all cultures except one in which spontaneous immortalization occurred. Cells could be successfully cultured even after a period of storage at 4°C and cultured cells were capable of being used for a variety of applications including functional assays. Upon functional assessment there was minimal intra-tumour heterogeneity. It is therefore possible to derive viable ovarian cancer cell cultures in the majority of patients undergoing surgery. Cells cultured directly from patient cancers provide an accurate and highly diverse model.

Clinicopathological features of homologous recombination-deficient epithelial ovarian cancers: sensitivity to PARP inhibitors, platinum, and survival.

Up to 50% of epithelial ovarian cancers (EOC) display defects in the homologous recombination (HR) pathway. We sought to determine the ramifications of the homologous recombination-deficient (HRD) status on the clinicopathologic features, chemotherapy response, and survival outcomes of patients with EOCs. HR status was determined in primary cultures from ascitic fluid in 50 chemotherapy-naïve patients by a functional RAD51 immunofluorescence assay and correlated with in vitro sensitivity to the PARP inhibitor (PARPi), rucaparib. All patients went on to receive platinum-based chemotherapy; platinum sensitivity, tumor progression, and overall survival were compared prospectively in HR-competent versus HRD patients. Compared with HR-competent patients, the HRD group was predominantly serous with a higher median CA125 at presentation. HRD was associated with higher ex vivo PARPi sensitivity and clinical platinum sensitivity. Median follow-up duration was 14 months; patients in the HRD group had lower tumor progression rates at 6 months, lower overall/disease-specific death rates at 12 months, and higher median survival. We therefore suggest that HRD as predicted by a functional RAD51 assay correlates with in vitro PARPi sensitivity, clinical platinum sensitivity, and improved survival outcome.