Prognostic factors and clinic-pathologic characteristics of ovarian tumor with different histologic subtypes—a SEER database population study of 41,376 cases

BACKGROUND: Ovarian cancer is considered the leading cause of cancer-related deaths among all gynecological malignancies and a significant reason for mortality in women. This cohort study aimed to explore the survival trends of malignant ovarian tumors (MOT), cancer antigen 125 (CA125) level, and clinicopathological prognostic factors of MOT by histological subtype. METHODS: Using the Surveillance, Epidemiology, and End Results (SEER) database, a total of 41,411 MOT cases diagnosed between January 2005 and December 2014 were extracted. According to the histological classification of MOT, four categories were included: epithelial ovarian carcinoma (EOC), malignant ovarian germ cell tumors (MOGCTs), malignant ovarian sex cord-stromal tumors (MOSCSTs) and ovarian neuroendocrine tumors (ONTs). We analyzed disease-specific survival (DS) and overall survival (OS) among the four categories, and their histological subtypes. Kaplan-Meier method was used to estimate survival curves, and log-rank test was used to evaluate differences between curves. Univariate and multivariate Cox proportional hazards models were applied to evaluate the prognostic impact of MOT. RESULTS: Significant predictors related to improved OS were younger age, low grade, early FIGO stage and localized SEER stage, while positive/elevated CA125 level was a risk factor. For MOGCT and MOSCST, 3-, 5- and 10-year DS rate estimates were all >80%, followed by ONT around 70%. Malignant epithelial cancer showed low DS rate at 3-year (70.7%), 5-year (58.7%), and 10-year (47.3%). CONCLUSIONS: EOC patients had the worst outcome, whereas MOGCT cases had the most favorable survival. Positive/elevated CA125 level led to poor prognosis. Furthermore, younger age, low grade, early FIGO stage and localized SEER stage were significant predictors for improved OS.