DISEASE CHARACTERISTICS: Diagnosis of testicular or extragonadal male germ cell tumors Must meet 1 of the following conditions after completion of platinum-based first-line chemotherapy: Complete remission (CR) followed by relapse Partial remission (PR) Prior resection of viable malignancy with elevated tumor markers allowed Initial bulky disease with no CR (significantly reduced but still abnormal in plateau) allowed if there is an increase in biological tumor markers or development of new metastases Seminoma with relapse after CR or PR to cisplatin-based chemotherapy allowed No pure seminoma pre-treated with carboplatin No refractory disease (i.e., documented increase in tumor burden and/or serum tumor marker level during or within 1 month after platinum-containing chemotherapy) CNS involvement allowed