Abstract
BACKGROUND: Endometrioid epithelial ovarian cancer (EEOC) is rare, and its management poorly defined. We examined factors associated with 5-year progression-free survival (PFS) after surgery for EEOC. METHODS: Retrospective study: treatment and outcomes of all EEOC patients undergoing initial surgery at, or presenting to, our institution within 3 months of initial surgery, 1/2002-9/2017. RESULTS: In total, 212 patients were identified. Median follow-up, 63.9 months (range, 0.7-192); median age at diagnosis, 52 years (range, 20-88); disease stage: I, n = 145 (68%); II, n = 47 (22%); III/IV, n = 20 (9%); FIGO grade: 1, 127 (60%); 2, 66 (31%); 3, 17 (8%); unknown, 2 (1%). One hundred twenty-eight (60%) had endometriosis; 75 (35%), synchronous endometrioid endometrial cancer (80%, IA); 101 (48%), complete surgical staging; 8 (5%), positive pelvic lymph nodes (LNs); 6 (4%), positive para-aortic LNs; 176 (97%), complete gross resection; 123 (60%), postoperative chemotherapy; 56(28%), no additional treatment. Five-year PFS, 83% (95% confidence interval [CI]: 76.6%-87.8%); 5-year overall survival (OS), 92.7% (95% CI: 87.7%-95.8%). Age, stage, and surgical staging were associated with improved 5-year PFS, and younger age at diagnosis with improved 5-year OS (p < 0.001). Chemotherapy did not improve 5-year PFS in IA/IB versus observation, but improved survival in IC (hazard ratio [HR]: 1.01, 95% CI: 0.22-4.59, p = 0.99; HR: 0.17, 95% CI: 0.04-0.7, p = 0.006). CONCLUSIONS: Age, stage, and full surgical staging were associated with improved 5-year PFS. Chemotherapy showed no benefit in IA/IB disease.