adjuvant chemotherapy, clinical practice, epithelial ovarian cancer, low risk, survival, Neoplasms. Tumors. Oncology. Including cancer and carcinogens, RC254-282

Background: Whether or not patients with stage I epithelial ovarian cancer (EOC) benefit from postoperative chemotherapy in the Asian population remains unclear. This retrospective cohort study was aimed at investigating the use of adjuvant chemotherapy in clinical practice to treat patients with early-stage EOC considering clinical factors. Materials and Methods: A total of 414 patients with the International Federation of Gynecology and Obstetrics (FIGO) stage IA–IC and grade 1 EOC were enrolled from the Taiwan Cancer Registry. We used multivariable Cox proportional-hazards models to control for clinical factors. The overall survival (OS) and disease-free survival (DFS) were estimated with the Kaplan–Meier method. Results: DFS did not improve significantly for patients with FIGO stage IA/IB EOC receiving adjuvant chemotherapy, with a 10-year DFS rate of 98% and 88% for those with and without adjuvant chemotherapy, respectively (hazard ratio [HR] = 0.41, 95% confidence interval [CI]: 0.05–3.36). OS did not improve significantly for patients with FIGO stage IA/IB EOC with adjuvant chemotherapy (HR = 0.86, 95% CI: 0.18–4.22) or stage IC (HR = 0.50, 95% CI: 0.10–2.45). OS did not differ significantly for patients with optimal (10-year OS: 92% with chemotherapy and 86% without chemotherapy in the log-rank test, P = 0.629) or nonoptimal staging (10-year OS: 73% with chemotherapy and 90% without chemotherapy in the log-rank test, P = 0.959). Conclusion: Adjuvant chemotherapy did not improve the prognosis of patients with low to intermediate-risk EOC and optimal/nonoptimal surgery. This result should be considered in clinical practice.