[Results of surgical treatment for pimary germcell tumors of the mediastinum].

Primary germ cell tumors of the mediastinum are relatively rare with complicated backgrounds including various pathology with mixed types and characteristics. The primary treatment for mature teratoma is surgical resection. It is sometimes difficult because of the giant tumor size and severe adhesion. Pneumonectomy is sometimes necessary to resect a tumor completely. In elderly patients, mature teratomas possibly involve epithelial malignant transformation. Cisplatin-based chemotherapy plays an important role in the treatment of both seminoma and nonseminoma. In our institution, 10-year survival rates are 91.7% for seminoma and 53.0% for nonseminoma. In terms of survival, nonseminoma has a worse prognosis compared with seminoma. Cases with pleural dissemination or metastasis also have a worse prognosis, with a median survival time of 5 months. The reasons for the poor prognosis in nonseminoma are the inclusion of patients in whom chemotherapy is not effective and those with advanced disease with metastasis. It would be possible to improve the prognosis with the establishment of a standard treatment regimen, development of new agents for the treatment of tumors resistant to current chemotherapy regimens, and detection of more tumors in the early stage.