Real-world Treatment Patterns and Outcomes after Fourth Recurrence in Epithelial Ovarian Cancer: A Single-center Retrospective Cohort Study

Aim: Evidence guiding treatment beyond the third recurrence of epithelial ovarian cancer (EOC) remains limited because most prospective studies have focused on earlier relapse settings.We evaluated real-world treatment patterns, clinical outcomes, and prognostic factors in patients who reached a fourth documented recurrence.Methods: This retrospective single-center cohort study included patients with EOC, fallopian tube, or primary peritoneal carcinoma who developed a fourth recurrence between January 2004 and July 2023.Treatment patterns, treatment response, overall survival (OS), and prognostic factors were evaluated using Kaplan-Meier survival analysis and Cox regression.Results: Ninety-one patients reached their fourth recurrence; 72 (79.1%) received systemic therapy and 19 (20.9%) received best supportive care.The most common regimens were: irinotecan/topotecan (22.2%), carboplatin plus paclitaxel (16.7%), pegylated liposomal doxorubicin (13.9%), and platinum plus gemcitabine (11.1%).Among 62 evaluable patients, the objective response rate and disease control rate were 9.7% and 17.7%, respectively.Among patients receiving systemic therapy, median OS from the fourth recurrence was 13.8 months [95% confidence interval (CI), 8.4-19.1].Platinum-containing therapy was associated with a numerically longer median OS than non-platinum therapy (18.4 vs. 12.7 months); this difference was not statistically significant (p=0.446).In univariable Cox analysis, higher serum albumin levels were associated with improved OS (hazard ratio 0.58, 95% CI 0.39-0.88;p=0.010).Conclusion: Patients experiencing a fourth recurrence of EOC have limited therapeutic options and modest responses to treatment.Median survival after the fourth recurrence exceeded one year among patients receiving systemic therapy.Serum albumin may serve as a simple prognostic marker and warrants further evaluation in larger prospective studies.