Objective: To compare the survival of patients with bilateral versus unilateral malignant ovarian germ cell tumors (OGCT).

Methods: Patients with a diagnosis of OGCT were identified from the Surveillance, Epidemiology, and End Results Program for the period 1988 to 2006 and were divided into bilateral and unilateral subgroups. Only surgically treated patients were included. Histologic types were grouped into dysgerminoma, malignant teratoma, and mixed germ cell tumors with pure nondysgerminoma cell tumors. Statistical analysis using Wilcoxon rank sum test, Kaplan-Meier survival methods, and Cox proportional hazards regression model were performed.

Results: In 1529 patients with OGCT, 1463 (95.7%) were unilateral and 66 (4.3%) were bilateral. Bilaterality was more common with dysgerminomas (6.5%) and mixed germ cell tumors with pure nondysgerminoma cell tumors (6.25%) than with immature teratomas (1.7%), P < 0.001. Most OGCT (67.3%) were stage I. Bilateral OGCT were more likely than unilateral tumors to be associated with advanced-stage disease (FIGO III and IV, 41% vs 20%, P < 0.04). Overall 5-year survival was 93.6% for unilateral OGCT and 80.7% in bilateral OGCT, P < 0.001. In multivariate analysis, bilaterality was not an independent predictor of survival when controlling for age, histology, stage, and surgical staging (hazard ratio, 1.3; 95% confidence interval, 0.7-2.5; P = 0.40).

Conclusions: Compared with unilateral tumors, bilateral OGCT are more often associated with advanced-stage disease, high-risk histology, and poor survival. When other prognostic factors are accounted for, bilaterality was not an independent prognostic predictor of survival.