Surgical treatment confers prognostic significance in pediatric malignant mediastinal germ cell tumors

Background: Primary malignant mediastinal germ cell tumors (GCTs) are rare pediatric tumors that have a poorer prognosis compared to GCTs occurring elsewhere in the body. The current study aimed to assess the prognostic factors and treatment outcomes of children with primary malignant mediastinal GCT in Taiwan. Methods: The authors retrospectively reviewed children 0–18 years old who were newly diagnosed with primary malignant mediastinal GCT between January 1, 2005 and December 31, 2019 and were registered in the Taiwan Pediatric Oncology Group patient registry. The impact of presenting characteristics, including sex, age, tumor stage, histology subtype, surgical treatment, and chemotherapy regimens of the patients were analyzed. Results: This study enrolled 52 children with malignant mediastinal GCT who had a median age of 16.0 (range, 6.0–17.9) years at diagnosis. The most common histological subtypes were mixed GCTs (n = 20) and yolk sac tumors (n = 15). Advanced disease stage and choriocarcinoma histology subtype were associated inferior outcomes. Children who received surgical treatment exhibited better outcomes compared to those who did not (5-year overall survival, 78% vs. 7%, p <.001). After comparing patients who received first-line cisplatin- and carboplatin-based chemotherapy, no difference in treatment outcomes was observed. Multivariate analysis showed that surgical management was the only independent predictor for superior OS. Conclusions: Surgical treatment is recommended for mediastinal GCT. Cisplatin-based chemotherapy was not superior to carboplatin-based chemotherapy as first-line treatment and may be avoided due to toxicity concerns.