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

To evaluate oncologic outcomes in patients with epithelial ovarian cancer (EOC) amid evolving surgical and systemic therapy paradigms.

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.

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).

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.