Ovarian cancer risk score predicts chemo-response and outcome in epithelial ovarian carcinoma patients

Objective: Cytoreductive surgery followed by adjuvant chemotherapy is a standard frontline treatment for epithelial ovarian cancer (EOC). We aimed to develop an ovarian cancer risk score (OVRS) based on the expression of 10 ovarian-cancer-related genes to predict the chemoresistance, and outcomes of EOC patients. Methods: We designed a case-control study with total 149 EOC women including 75 chemosensitives and 74 chemoresistants. Gene expression was measured using the quantitative real-time polymerase chain reaction. We tested for correlation between the OVRS and chemosensitivity or chemoresistance, disease-free survival (DFS), and overall survival (OS), and validated the OVRS by analyzing patients from the TCGA database. Results: The chemosensitive group had lower OVRS than the chemoresistant group (5 vs. 15, p=0.001, Mann-Whitney U test). Patients with disease relapse (13 vs. 5, p<0.001, Mann-Whitney U test) or disease-related death (13.5 vs. 6, p<0.001) had higher OVRS than those without. OVRS >= 10 (hazard ratio=3.29; 95% confidence interval=1.94-5.58; p<0.001) was the only predictor for chemoresistance in multivariate analysis. The median DFS (5 months vs. 24 months) and OS (39 months vs. >60 months) of patients with OVRS >= 10 were significantly shorter than those of patients with OVRS <9). The high OVRS group also had significantly shorter median OS than the low OVRS group in 255 patients in the TCGA database (39 vs. 49 months, p=0.046). Conclusions: Specific genes panel can be clinically applied in predicting the chemoresistance and outcome, and decision-making of epithelial ovarian cancer.