Epidemiology and treatment of malignant ovarian germ cell and sex cord stromal tumors in germany: a population-based cancer registry study from 2016 – 2021

Malignant ovarian germ cell tumors (MOGCT) and ovarian sex cord stromal tumors (SCST) are rare ovarian tumors. Since 2013, all German federal states are obliged to record data on diagnosis, pathology, therapy, and clinical course of tumor diseases. We gathered data on MOGCT and SCST from thirteen federal cancer registries and the German Childhood Cancer Registry. Each of the participating registries provided aggregated data on MOGCT and SCST with date of diagnosis between 01.01.2016 and 31.12.2021. 629 MOGCT and 872 SCST were included, age peaks at diagnosis for MOGCT and SCST were between 20 and 24 years and between 55 and 59 years, respectively. Of all MOGCT, 23%, 22%, 13% and 12% were malignant teratoma, dysgerminoma, neuroendocrine tumors and yolk sac tumors, respectively. The large majority (94%) of SCST represented malignant granulosa cell tumors. Most tumors were diagnosed in FIGO stage I (66% of MOGCT and 85% of SCST). Surgery was reported in 58% of patients with MOGCT and in 73% of patients with SCST. Chemotherapy was administered to 26% of MOGCT patients and 8% of SCST patients. This study highlights the great potential of cancer registries as high numbers of patients are recorded, however, data are highly dependent on the reporting institutions.