Purpose: Poly(ADP-ribose) polymerase (PARP) inhibitors selectively target homologous recombination (HR)-defective cells and show good clinical activity in hereditary breast and ovarian cancer associated with BRCA1 or BRCA2 mutations. A high proportion (up to 50%) of sporadic epithelial ovarian cancers (EOC) could be deficient in HR due to genetic or epigenetic inactivation of BRCA1/BRCA2 or other HR genes. Therefore, there is a potential for extending the use of PARP inhibitors to these patients if HR status can be identified. We developed a functional assay of HR status in primary cultures of EOCs based on Rad51 focus formation that correlates well with sensitivity to the potent PARP inhibitor AG014699.Experimental Design: Primary cultures were derived from ascitic fluid from patients with EOCs. HR status was investigated by γH2AX and Rad51 focus formation by immunofluorescence. Cytotoxicity to PARP inhibitors was tested by sulforhodamine B and survival assay.Results: Twenty-five cultures were evaluated for HR status and cytotoxicity to PARP inhibitor. Following exposure to AG014699, there was an increase in Rad51 foci (HR competent) in 9 of 24 (36%) but no increase (HR deficient) in 16 of 24 (64%) cultures. Cytotoxicity was observed in 15 of 16 (93%) HRdeficient samples but not in 9 of 9 HR-competent samples following 24-hour exposure to 10 μmol/L AG014699.Conclusion: HR status can be determined in primary cancer samples by Rad51 focus formation, and this correlates with in vitro response to PARP inhibition. Use of this assay as a biomarker now needs testing in the setting of a clinical trial.

During primary surgery for advanced stage epithelial ovarian cancer all attempts should be made to achieve complete cytoreduction. When this is not achievable, the surgical goal should be optimal (< 1 cm) residual disease. Due to the high risk of bias in the current evidence, randomised controlled trials should be performed to determine whether it is the surgical intervention or patient-related and disease-related factors that are associated with the improved survival in these groups of women. The findings of this review that women with residual disease < 1 cm still do better than women with residual disease > 1 cm should prompt the surgical community to retain this category and consider re-defining it as 'near optimal' cytoreduction, reserving the term 'suboptimal' cytoreduction to cases where the residual disease is > 1 cm (optimal/near optimal/suboptimal instead of complete/optimal/suboptimal).

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-na€ ve 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/diseasespecific 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. Cancer Res; 72(22); 5675-82. Ó2012 AACR.

BackgroundThe standard management of primary ovarian cancer is optimal cytoreductive surgery followed by platinum-based chemotherapy. Most women with primary ovarian cancer achieve remission on this combination therapy. For women achieving clinical remission after completion of initial treatment, most (60%) with advanced epithelial ovarian cancer will ultimately develop recurrent disease. However, the standard treatment of women with recurrent ovarian cancer remains poorly defined. Surgery for recurrent ovarian cancer has been suggested to be associated with increased overall survival. ObjectivesTo evaluate the effectiveness and safety of optimal secondary cytoreductive surgery for women with recurrent epithelial ovarian cancer. To assess the impact of various residual tumour sizes, over a range between 0 cm and 2 cm, on overall survival. Search methodsWe searched the Cochrane Gynaecological Cancer Group Trials Register, MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials (CENTRAL) up to December 2012. We also searched registers of clinical trials, abstracts of scientific meetings, reference lists of included studies and contacted experts in the field. For databases other than MEDLINE, the search strategy has been adapted accordingly. Selection criteriaRetrospective data on residual disease, or data from randomised controlled trials (RCTs) or prospective/retrospective observational studies that included a multivariate analysis of 50 or more adult women with recurrent epithelial ovarian cancer, who underwent secondary cytoreductive surgery with adjuvant chemotherapy. We only included studies that defined optimal cytoreduction as surgery leading to residual tumours with a maximum diameter of any threshold up to 2 cm. Data collection and analysisTwo review authors (KG, TA) independently abstracted data and assessed risk of bias. Where possible the data were synthesised in a meta-analysis.