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

Abstract

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

Methods: 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.

Results: 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.

Conclusion: 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.