The prevalence and prognostic impact of lymph node metastasis in malignant germ cell tumors of the ovary.

BACKGROUND: The purpose of this study is to report the prevalence and prognostic importance of lymph node metastasis in malignant germ cell tumors of the ovary (OGCT).

METHODS: Demographic and clinicopathologic information were abstracted from the Surveillance, Epidemiology, and End Results Program (SEER) from 1988 to 2004. Patients with a histologic diagnosis of OGCT after surgical resection were included. The study population was divided into Cohort A (lymph node metastasis absent) and Cohort B (lymph node metastasis present). Statistical analysis using Fisher's Exact Test, Kaplan-Meier survival methods, and Cox regression proportional hazards were performed.

RESULTS: In 613 patients with lymphadenectomy, the prevalence of lymphnode metastasis was 18.1% (111/613). In dysgerminoma, malignant teratoma and mixed germ cell tumors including pure non-dysgerminoma histology, the lymphnode metastasis was present in 28%, 8% and 16% patients respectively (p<0.05). Age, race, grade and extent of lymph node dissection influenced lymph node involvement but this was statistically not significant. Five year survival in Cohort A was 95.7% compared to 82.8% in Cohort B (p<0.001). After controlling for age, race, stage, grade and histology, multivariate analysis revealed the presence of lymph node involvement as an independent predictor of poor survival with a hazards ratio of 2.87 (95% CI 1.439-5.725; p<0.05).

CONCLUSIONS: Prevalence of lymph node metastasis varies according to histology in OGCT and is an independent predictor of poor survival in these patients. These findings highlight the value of lymphadenectomy and may be helpful in creating risk stratification models for individualization of adjuvant therapies.