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.