Recurrence Patterns and Survival Outcomes in Chinese Patients with Surgically Treated Recurrent Ovarian Clear Cell Carcinoma: A Single Institutional Analysis of 45 Cases

Background: To evaluate the recurrence patterns and survival outcomes of surgically treated relapsed ovarian clear cell carcinoma (OCCC) patients. Methods: We performed a comprehensive retrospective analysis of all the patients who underwent secondary debulking from 2004/10 to 2019/04. Results: In total, 45 eligible patients were included. 75.6% of the patients had early-stage disease and platinum-sensitive recurrence accounted for 70.5%. The median progression-free survival after primary surgery (PFS 1) was 20 months (range, 2-137). Of all, 64.4% patients had solitary recurrence and 86.7% patients had no residual disease after secondary surgery. Regarding tumor distribution, the most common site was pelvis (47.5%), followed by lymph node metastases (18.0%) and abdominal wall lesions (8.2%). For the entire population, the median disease-free survival after recurrence (PFS 2) and post-relapse survival (PRS) was 15 months (range, 0-96), and 24 months (range, 3-159), respectively. Eight patients (17.8%) had a prolonged PFS2 more than 30 months. Patients with localized relapse had better survival including PFS 2 (P=0.023), PRS (P=0.004), and overall survival (OS) (P=0.029). Patients who achieved complete resection tended to have longer PFS 2 (P=0.017). After multivariate analysis, complete resection at recurrence remained as an independent positive predictor for PFS 2 (P=0.022). The median OS was 50 months and was significantly associated with platinum response (P=0.003) and number of relapsed lesions (P=0.002). Conclusion: A high rate of pelvic recurrence was noted in this population. Patients with focal recurrence had a favorable prognosis. Complete resection at secondary debulking proved to be an independent predictor for disease-free survival.