ABSTRACT Purpose Ovarian cancer is the most lethal gynecological malignancy, and chemotherapy strategies have evolved substantially over recent decades. This study aimed to evaluate whether survival outcomes of epithelial ovarian cancer (EOC) have improved over time and to explore trends in younger patients of reproductive age. Basic Procedures We retrospectively analyzed real‐world data from the Tokai Ovarian Tumor Study Group. A total of 2824 patients with EOC who were diagnosed between 1986 and 2019 were included. Patients were categorized into three groups according to treatment initiation: Group 1 (1986–1995), Group 2 (1996–2013), and Group 3 (2014 onward). Overall survival (OS) was assessed using the log‐rank test, and stratified analyses were performed by stage and histological subtype. Subgroup analysis was conducted for patients aged ≤ 45 years. Main Findings Five‐year OS differed significantly among the three groups ( p < 0.01), demonstrating improved survival over time. Stratified analyses revealed significant benefits in advanced‐stage disease and in chemotherapy‐sensitive histologies such as serous and endometrioid carcinoma. Clear cell carcinoma showed modest improvement, whereas mucinous carcinoma showed no significant change. Among patients aged ≤ 45 years, five‐year OS showed a trend toward improvement but did not reach statistical significance ( p = 0.16). Principal Conclusions Survival outcomes for ovarian cancer have improved in recent decades, particularly in advanced‐stage disease and chemotherapy‐sensitive subtypes. Advances in systemic therapy, including the introduction of maintenance strategies, likely contributed to this improvement. Continued data accumulation is essential to clarify treatment efficacy in younger patients and to inform fertility‐preserving approaches.
Miyamoto et al. (Fri,) studied this question.