Adjuvant Pelvic Radiotherapy in Ovarian Cancer: Outcomes By Risk Factors

Abstract Background: Radiotherapy (RT) is not the current standard treatment option for ovarian cancer (OC) patients. The present study aims to explore the risk factors of adjuvant pelvic RT for patients with OC and to investigate prognostic factors associated with longer progression free survival (PFS) and overall survival (OS) period.Methods: From April 2004 to September 2020, OC patients administered with RT were collected retrospectively at our institution and those who received pelvic RT were selected for further analysis. Kaplan-Meier method was employed to estimate the PFS, OS and local control (LC) rate. Univariate and multivariate cox regression model were established to identify potential beneficiaries of pelvic RT.Results: Overall, a total of 89 OC patients underwent RT were identified, 70 of whom were treated with adjuvant pelvic RT and were eligible for final analysis. Median follow-up was 51.0 months. The estimated 3-year OS rate was 48.1% and 3-year PFS rate was 26.8%, respectively. CACTE grade 4 to 5 toxicities were observed in 2 patients. Multivariate cox model illustrated that high-grade serous carcinoma (HGSC), advanced stage disease (FIGO stage III & IV), receiving pelvic RT during multiple relapses as well as no previous chemotherapy (CT) were independent risk factors for PFS. Additionally, patients with 0-1 risk factor had a longer PFS time than those with 2-4 risk factors.Conclusions: Pelvic RT was well tolerated and had favorable efficacy in OC patients with low risk factor (0-1), which might confer prolonged survival. However, further investigations are needed.