Impact of radiation timing on survival outcomes in ovarian cancer: Analysis of the SEER Database

: The optimal timing of radiation therapy in relation to surgery for ovarian cancer remains controversial. This study aimed to evaluate the prognostic impact of preoperative versus postoperative radiation on survival outcomes using a large population-based cohort. : We conducted a retrospective analysis of 3,595 ovarian cancer patients from the Surveillance, Epidemiology, and End Results (SEER) database, comparing 3,453 patients who received postoperative radiation with 142 who received preoperative radiation. Kaplan-Meier survival analysis and Cox proportional hazards regression were performed to assess overall survival. A prognostic nomogram was developed and validated using ROC curve analysis. : Patients receiving preoperative radiation had significantly larger tumors (78.91±204.14mm vs 51.16±146.78mm, p=0.009), more advanced stage disease (p<0.001), and higher rates of chemotherapy use (64.08% vs 36.35%, p<0.001). Multivariate analysis identified preoperative radiation as an independent predictor of worse survival (HR=1.64, 95% CI: 1.27-2.11, p<0.001). Other significant prognostic factors included advanced age (HR=1.50), higher stage (Stage III: HR=1.87), presence of distant metastasis (HR=1.80), and unmarried status. Kaplan-Meier analysis confirmed significantly worse survival in the preoperative radiation group (p=5.8e-5). The prognostic nomogram incorporating these factors demonstrated good discriminative ability with AUC values approaching 0.8. : Postoperative radiation therapy is associated with significantly improved survival compared to preoperative radiation in ovarian cancer patients.