Oncologic outcome after recurrence in patients with stage i epithelial ovarian cancer: Are clear-cell and mucinous histological types a different entities?

Objectives: This study was conducted to estimate the oncologic outcome of stage I epithelial ovarian carcinoma (EOC) patients after recurrence.

Study design: After central pathological review and searching of the medical records of multi- institutions, a total of 103 relapsed patients with stage I EOC were analyzed. The major endpoint was postrecurrence survival (PRS).

Results: The median follow-up for surviving patients was 57.5 (5.7-242.0) months. The median age was 52 (14-89). Among the patients, 19 (18.4%) had FIGO IA disease, and 4 (3.9%) and 80 (77.7%) had IB and IC disease, respectively. Regarding the histological type, the clear-cell type was the most frequently observed (N = 42: 40.8%). The 3/5-year overall and PRS rates of all patients were 63.7/47.9 and 38.2/ 24.0%, respectively. The 5-year PRS rates of patients with serous, endometrioid, clear-cell, and mucinous tumors were 44.9, 35.0, 19.8, and 0%, respectively. On stratifying by the histological type, the overall and postrecurrence survival rates of patients with the mucinous/clear-cell types were significantly poorer than in those with the non-mucinous/clear-cell types (OS: P = 0.0253, PRS: P = 0.0016). In multivariate analyses, the FIGO stage (IA/IB vs. IC) and histological type (clear-cell/mucinous vs. non- clear-cell/ mucinous) retained their significance as prognostic factors of a poorer PRS {stage IC (vs. IA/B): HR: 2.176 (95% CI: 1.059-4.470), P = 0.0343: clear-cell/mucinous (vs. non- clear-cell/mucinous): HR: 2.486(95% CI: 1.416-4.364), P = 0.0015).

Conclusions: Even if at stage I, once patients with a mucinous/clear-cell histology experience recurrence, subsequent survival is extremely poor.