Malignant ovarian germ cell tumors: presentation, survival and second cancer in a population based Norwegian cohort (1953-2009).

ABSTRACT

PURPOSE: To quantify and compare survival in women with malignant ovarian germ cell tumors (MOGCTs) in Norway before and after the introduction of cisplatin-based chemotherapy (around 1980), and to explore the association between different types of treatment and the development of a second cancer. PATIENTS AND METHODS: We identified 351 patients diagnosed with MOGCTs from 1953 to 2009 in the Cancer Registry of Norway. Ovarian cancer-specific survival was calculated separately for patients diagnosed before and after 1980. Patients were divided into subgroups by histological subtype (pure dysgerminoma, malignant teratoma, other MOGCTs) and extent of disease (localized and metastatic). We estimated the cumulative incidence of a second cancer in 10-year MOGCT survivors. Kaplan-Meier estimates were used, and p<0.05 was considered significant. RESULTS: 20-Year ovarian cancer-specific survival increased from 59% (95% CI 51% to 66%) before 1980 to 88% (95% CI 83%-93%) thereafter. Significant improvement was observed in all subgroups. No second cancer was diagnosed in any of 31 10-year MOGCT survivors treated with surgery only; second cancer was diagnosed in 23 of 139 patients who underwent cytotoxic treatment (98 radiotherapy ± chemotherapy, 41 chemotherapy only; p=0.08). Patients aged >50 years had a significantly poorer ovarian cancer-specific survival than younger patients (HR=5.98, 95% CI 3.39-10.57) after adjustment for histological subtype and stage at presentation. Our results favor the treatment of patients with metastatic MOGCTs at large cancer centers. CONCLUSION: Today women with MOGCTs have an excellent prognosis if treated according to modern therapeutic principles.