Treatment patterns and survival outcomes according to histologic subtype in malignant ovarian germ cell tumors: a nationwide real-world cohort study

To investigate real-world treatment patterns and survival outcomes by histologic subtype in patients with malignant ovarian germ cell tumors (MOGCTs) in Korea.

Using the Cancer Public Library Database, a retrospective cohort study was conducted including adult patients newly diagnosed with MOGCTs between 2013 and 2018. Patients were categorized into 3 histologic subtypes: dysgerminoma, non-dysgerminomatous germ cell tumors (ND-GCTs; yolk sac tumor, embryonal carcinoma, and mixed germ cell tumor [GCT]), and malignant teratomatous germ cell tumors (immature teratoma and teratocarcinoma). Initial treatment patterns, including surgery and chemotherapy, were examined. Overall survival (OS) was assessed by histologic subtype using the Kaplan-Meier method. In localized-stage patients, OS and time to first subsequent therapy or death (TFST) were estimated by adjuvant chemotherapy use, with subgroup analysis by histology.

A total of 332 patients were included (27.7% dysgerminomas, 33.4% ND-GCTs, 38.9% malignant teratomatous GCTs). In localized disease, surgery alone was common in dysgerminomas (57.6%), while adjuvant chemotherapy was frequently used in ND-GCTs (88.5%) and malignant teratomatous GCTs (60.0%). Adjuvant chemotherapy was associated with longer TFST overall (p<0.01), but no OS benefit (p=0.22). In subgroup analysis, adjuvant chemotherapy was associated with longer TFST in ND-GCTs (p<0.01) and malignant teratomatous GCTs (p=0.04), but not in dysgerminomas. No significant differences in OS were observed in any group.

This study highlights distinct treatment patterns and outcomes by histologic subtype in MOGCTs. These findings support the value of large population-based data in guiding treatment decisions for rare ovarian tumor subtypes.