Is high-dose chemotherapy after primary chemotherapy a therapeutic option for patients with primary mediastinal nonseminomatous germ cell tumor?

Patients with primary mediastinal nonseminomatous germ cell tumors have a poor prognosis, with a 5-year overall survival of nearly 50%. We investigated the feasibility and activity of early high-dose chemotherapy (HDCT) in these patients. After conventional induction chemotherapy, patients underwent a single shot of HDCT consisting of carboplatin, etoposide, and cyclophosphamide, followed by peripheral blood progenitor cell support. Twenty-one patients were considered for treatment with HDCT. Median age was 29 years (range, 19-55 years). Eight (38%) patients had lung metastases. After primary chemotherapy, 7 patients achieved complete remission, 4 achieved partial remission with negative marker, 1 achieved partial remission with positive marker, 2 had stable disease, and 7 progressive disease. Twelve patients were not treated with HDCT due to progressive disease and poor physical conditions. No HDCT-related deaths or irreversible organ toxicities were observed. Residual surgery after HDCT was performed in 4 patients and resulted in 3 pathologic complete remissions. With a median follow-up of 52 months (range, 15-71 months) in 9 patients treated with HDCT, 8 have been continuously free of disease. Of 12 patients who did not receive HDCT, 0 was alive at 2 years from diagnosis. A single course of HDCT after induction chemotherapy appeared to be inapplicable in most of our patients, mainly due to early progressive disease. These data should be considered in the analysis of retrospective series and in the design of new prospective trials with HDCT in these patients. Earlier HDCT administration followed by residual surgery should be considered for further investigation.