What proportion of patients with stage 3 ovarian cancer are potentially cured following intraperitoneal chemotherapy? Analysis of the long term (≥10 years) survivors in NRG/GOG randomized clinical trials of intraperitoneal and intravenous chemotherapy in stage III ovarian cancer

Objective: Patients with advanced epithelial ovarian cancer (EOC) alive without progression at a landmark time-point of 10 years from diagnosis are likely cured. We report the proportion of patients with Stage III EOC who were long-term disease-free survivors (LTDFS≥10 years) following either intraperitoneal (IP) or intravenous (IV) chemotherapy as well as the predictors of LTDFS. Methods: Data from 3 mature NRG/GOG trials (104, 114, 172) were analyzed and included demographics, clinicopathologic details, route of administration, and survival outcomes of patients living ≥10 years assessed according to the Kaplan-Meier method. Cox regression survival analysis was performed to evaluate independent prognostic predictors of LTDFS. Results: Of 1174 patients randomized, 10-year overall survival (OS) was 26% (95% CI, 23–28%) and LTDFS ≥10 years was 18% (95% CI, 16–20%). Patients with LTDFS ≥10 years had a median age of 54.6 years (p < 0.001). Younger age (p < 0.001) was the only independent prognostic factor for LTDFS≥10 years on multivariate Cox analysis. Conclusions: Approximately 18% of patients were LTDFS ≥10 years. They form the tail end of the survival curve and are likely cured. Our results provide a comparative benchmark to evaluate the impact of PARP inhibitors in 1st line maintenance trials on survival outcomes.