Changes in Epithelial Ovarian Cancer Recurrence and Survival According to Treatment Paradigm Shifts

AIM: To evaluate oncologic outcomes in patients with epithelial ovarian cancer (EOC) amid evolving surgical and systemic therapy paradigms. METHODS: This retrospective cohort study included patients diagnosed with EOC from June 2003 to December 2020 at a single tertiary center, grouped by diagnosis period. Overall survival (OS) and progression-free survival (PFS) were analyzed using the Kaplan-Meier and Cox regression analyses. RESULTS: A total of 763 patients were classified as 2003-2008 (Group 1, n = 101), 2009-2013 (Group 2, n = 207), and 2014-2020 (Group 3, n = 455), reflecting changes in cytoreductive surgery and targeted therapies (bevacizumab and PARP inhibitors). Early-stage diagnoses increased over time without statistical significance (Stage I-II: Group 1, 37.6% vs. Group 3, 46.6%; p = 0.200). Group 2 showed greater use of interval debulking surgery (IDS), higher complete cytoreduction rates, and more first-line chemotherapy cycles (all p < 0.001). Group 3 represented the introduction of targeted therapies (p < 0.001 for both). IDS with residual (< 1 cm) was associated with poorer outcomes than complete/optimal primary debulking surgery (PDS) (hazard ratio 2.94, 95% confidence interval 1.5-5.8). Despite unchanged PFS, the 5-year OS improved from 64.0% to 82.5% among patients with advanced-stage disease (p = 0.024). CONCLUSIONS: Over two decades, with the advent of targeted therapies, complete cytoreduction (especially in PDS) has increased. Although the use of IDS also increased, residual disease (< 1 cm) after IDS was associated with poorer outcomes. While PFS remained unchanged, 5-year OS significantly improved among patients with advanced-stage disease diagnosed in the most recent period.