Clinical Features and Treatment Outcomes in Patients with Extragonadal Germ Cell Tumors: A Single-center Experience.

Background: The prognosis for non-seminomatous extragonadal germ cell tumors (EGCTs), especially mediastinal, has been shown to be worse than for seminomatous EGCTs. Patients and Methods: Fourteen patients with EGCT (seven pure seminomas and seven non-seminomas) were treated at the Kanazawa University Hospital between 1992 and 2014; the primary tumor sites were mediastinum in nine patients and retroperitoneum in five patients. All patients were treated with cisplatin-based combination chemotherapeutic regimens followed by a multimodal strategy that included high-dose chemotherapy (HDCT), aggressive surgery, and early salvage chemotherapy. Results: Although all patients with seminomatous EGCT achieved long-term survival, almost all patients with non-seminomatous EGCT had elevated serum tumor markers and high mortality rates. However, we experienced that patients with mediastinal non-seminomatous EGCT achieved long-term cancer-free survival with HDCT. The 5-year overall survival of patients with seminomatous and non-seminomatous EGCT was 100% and 44%, respectively. Conclusion: Herein we describe the treatment outcomes of patients with EGCT at our Institute and propose HDCT reconsideration for poor-risk patients.