Clinical Management of Malignant Ovarian Germ Cell Tumors: A 26-year Experience in a Tertiary Care Institution

Background: The standard prognostic system for malignant ovarian germ cell tumors (MOGCT) has not yet been established and the scope of surgery was also controversial. Mixed ovarian malignant germ cell tumor (mGCT) is a rare histological type of MOGCT with higher malignant degree than other types. The aim of the present study was to investigate the clinical features and prognosis of mGCT, and prognostic factors for MOGCT to provide guidance for future treatment.

Methods: Retrospective analysis was carried out on 137 patients, who were admitted from 1991 to 2014. Survival curves were constructed using Kaplan-Meier method and were compared with the log-rank test across various pathological types and different stages. Multivariate survival analysis was performed using Cox's proportional hazards model.

Results: There were 29 dysgerminomas (DG), 3 embryonal carcinomas (EC), 43 immature teratomas (IT), 48 yolk sac tumors (YST) and 14 mixed germ cell tumors (mGCT). The most common type of mGCT is YST (85.7%), followed by IT (64.3%), EC (28.6%), and DG (21.4%). The respective 5-year OS rates were 100% in DG, 100% in EC, 92.5% in IT, 54.5% in YST and 66.7% in mGCT, while the corresponding 5-year PFS rate were 89.7% in DG, 100% in EC, 85.1% in IT, 55.9% in YST and 60% in mGCT. FIGO stage Ⅲ-Ⅳ, certain pathological types (Yolk sac tumors and mGCT) and the number of postoperative chemotherapy courses were independently unfavorable prognostic in a multivariate model that included age, Admission decade, fertility-sparing surgery, and comprehensive staging surgery.

Conclusions: Fertility-sparing surgery and incomplete surgical staging did not affect the prognosis. It might be safe to preserve fertility and shrink the scope of the surgical procedures in MOGCT patients regardless of stage or pathology. However, prospective randomized controlled trials were needed for further evaluation.