High-dose chemotherapy with autologous stem-cell support for germ cell tumors: a critical review

High-dose chemotherapy (HDC) with autologous stem-cell support (ASCS) has been investigated in patients with cisplatin-resistant, relapsed, or poor-prognosis germ cell tumor (GCT). Although some of these patients have benefited from this approach, it is unknown when best to administer such therapy. This review categorizes the HDC/ASCS trials into those performed as (1) salvage therapy for second or greater relapse, (2) salvage therapy for first relapse, and (3) first-line therapy. From the trials performed to date, earlier use of HDC/ASCS (first-line or salvage therapy in first relapse) achieved a higher durable remission rate than when used later as salvage therapy in second or greater relapse (approximately 50% v 15%, respectively). HDC/ASCS is not beneficial for relapsed or cisplatin-resistant primary extragonadal GCT patients, but may have a role in testicular GCT who are not "absolutely" cisplatin-resistant. Trial differences regarding the patients selected and the high-dose transplant preparative regimen used have made precise comparative analyses difficult. There has been only one phase III trial and it did not show a survival advantage to the HDC/ASCS arm, although this trial had significant methodological difficulties. In the future, more definitive treatment recommendations may be made upon completion of two ongoing phase III trials comparing HDC/ASCS with standard chemotherapy in the first salvage and front-line settings.