Ex vivo assessment of cancer drug sensitivity in epithelial ovarian cancer and its association with histopathological type, treatment history and clinical outcome.

Epithelial ovarian cancer (EOC) is divided into type I and type II based on histopathological features. Type I is clinically more indolent, but also less sensitive to chemotherapy, compared with type II. The basis for this difference is not fully clarified. The present study investigated the pattern of drug activity in type I and type II EOC for standard cytotoxic drugs and recently introduced tyrosine kinase inhibitors (TKIs), and assessed the association with treatment history and clinical outcome. Isolated EOC tumor cells obtained at surgery were investigated for their sensitivity to seven standard cytotoxic drugs and nine TKIs using a short­term fluorescent microculture cytotoxicity assay (FMCA). Drug activity was compared with respect to EOC subtype, preoperative chemotherapy, cross­resistance and association with progression­free survival (PFS). Out of 128 EOC samples, 120 samples, including 21 type I and 99 type II, were successfully analyzed using FMCA. Patients with EOC type I had a significantly longer PFS time than patients with EOC type II (P=0.01). In line with clinical experience, EOC type I samples were generally more resistant than type II samples to both standard cytotoxic drugs and the TKIs, reaching statistical significance for cisplatin (P=0.03) and dasatinib (P=0.002). A similar pattern was noted in samples from patients treated with chemotherapy prior to surgery compared with treatment­naive samples, reaching statistical significance for fluorouracil, irinotecan, dasatinib and nintedanib (all P<0.05). PFS time gradually shortened with increasing degree of drug resistance. Cross­resistance between drugs was in most cases statistically significant yet moderate in degree (r<0.5). The clinically observed relative drug resistance of EOC type I, as well as in patients previously treated, is at least partly due to mechanisms in the tumor cells. These mechanisms seemingly also encompass kinase inhibitors. Ex vivo assessment of drug activity is suggested to have a role in the optimization of drug therapy in EOC.

Peritoneal cancer index predicts severe complications after ovarian cancer surgery.

INTRODUCTION: prediction and importance of severe postoperative complications after ovarian cancer surgery is a strong issue in patient selection and evaluation. Pre- and early peroperative predictors of severe 30-days postoperative complications (Clavien-Dindo class ≥3) after surgery for primary ovarian cancer are not fully established, neither their impact on patients' survival. MATERIALS AND METHODS: A prospective observational study included 256 patients with primary ovarian cancer FIGO stages IIB-IV, operated during 2009-2018 in a primary or interval debulking surgery setting. Patient variables were analysed in relation to severe postoperative complications (Clavien-Dindo class ≥3) and overall survival. RESULTS: High-grade postoperative complications occurred in 24.2% patients. Class 3a complications were observed in 12.5% cases. High-grade complications class ≥3 were observed in 31.6% after primary debulking surgery compared to 12.2% after interval debulking surgery (p = 0.0004). Peritoneal cancer index ≥21 and preoperative albumin concentration ≤33 g/L were independent predictors of high-grade complications. Peritoneal cancer index correlated with the surgical complexity score and completeness of cytoreduction. Increased peritoneal cancer index was a negative predictor of overall survival, but high-grade complications did not influence survival negatively. CONCLUSIONS: Peritoneal cancer index ≥21 was an independent predictor of high-grade complications after ovarian cancer surgery. Increased peritoneal cancer index also impacted overall survival negatively, but high-grade complications did not influence overall survival.