Platinum sensitivity drives prognosis in endometriosis-associated ovarian carcinoma compared with high-grade serous ovarian carcinoma: Insights from a 10-year retrospective study

Objective To compare clinical features, treatment responses, and survival outcomes between endometriosis-associated ovarian cancer (EAOC) and high-grade serous ovarian carcinoma (HGSOC), with a focus on platinum resistance. Materials and methods We conducted a 10-year retrospective study of 224 patients with epithelial ovarian cancer treated at a single tertiary medical center in Taiwan. Patients were classified as either EAOC (clear cell or endometrioid histology) or HGSOC. Clinical data, surgical outcomes, platinum sensitivity, and survival were analyzed. Results EAOC patients were younger, more often diagnosed at early stage, and achieved higher rates of optimal cytoreduction compared to HGSOC. Overall survival (OS) and progression-free survival (PFS) were significantly better in the EAOC group. However, survival advantages diminished after stratification by stage and platinum sensitivity. Notably, no platinum-resistant EAOC patient survived beyond 5 years, whereas a subset of platinum-resistant HGSOC patients achieved long-term survival. Conclusion Although EAOC generally confers a favorable prognosis due to earlier diagnosis and better surgical outcomes, platinum resistance remains a key driver of poor survival. These findings highlight the importance of tailored treatment approaches and early identification of chemoresistance, especially in clear cell subtypes prevalent in Asian populations.