High-Dose Chemotherapy and Autologous Peripheral-Blood Stem-Cell Transplantation for Relapsed Metastatic Germ Cell Tumors: The Indiana University Experience

Purpose Patients with relapsed metastatic germ cell tumor (GCT) can be cured with second-line and even third-line regimens. We report survival outcomes of patients treated with high-dose chemotherapy (HDCT) and peripheral-blood stem-cell transplantation (PBSCT) at Indiana University between 2004 and 2014. Patients and Methods We conducted a retrospective analysis of 364 consecutive patients with GCT who progressed after cisplatin-based combination chemotherapy and were subsequently treated with HDCT and PBSCT. Three hundred forty-one patients received two consecutive courses of HDCT consisting of 700 mg/m² carboplatin and 750 mg/m² etoposide, each for 3 consecutive days, and each followed by PBSCT. Twenty-three patients received only a single course of HDCT because of progressive disease or toxicity. Cox proportional hazards models were used to test predictors of disease progression. Results The median age was 32 years (range, 17 to 70 years). With a median follow-up of 3.3 years, the 2-year progression-free survival (PFS) was 60% (95% CI, 55% to 65%) and the 2-year overall survival was 66% (95% CI, 60% to 70%). Three hundred three patients received HDCT as second-line therapy with a 2-year PFS of 63% (95% CI, 57% to 68%), and 61 patients received HDCT as third-line or later therapy with a 2-year PFS of 49% (95% CI, 36% to 61%). In a multivariable analysis, factors associated with disease progression included use of HDCT as third-line or later therapy, platinum-refractory disease, mediastinal primary tumor site, nonseminoma histology, intermediate- or poor-risk disease at the time of GCT diagnosis, and human chorionic gonadotropin ≥ 1,000 mIU/mL at initiation of HDCT. There were nine treatment-related deaths. Secondary leukemia developed in five patients. Conclusion This large single-institution study demonstrates that patients with relapsed metastatic GCT are curable by HDCT plus PBSCT even when used in third-line or later therapy.