Late intensification in small-cell lung cancer: a phase I study of high doses of cyclophosphamide and etoposide with autologous bone marrow transplantation.

We conducted a late dose intensification pilot study of small-cell lung cancer (SCLC) treated with high doses of cyclophosphamide (200 mg/kg) and etoposide (1.0 to 3.5 g/m2), administered during a period of 48 hours, as well as autologous bone marrow infusion. We have been able to administer safely 3 g/m2 of etoposide with the autologous bone marrow infusion and 1.5 g/m2 without it. Limiting extrahematopoietic toxicity appeared to take the form of irreversible cardiac failure. Complete responses have been obtained with our regimen for late dose intensification, but the duration of the responses and the survival rates of the patients were poor. This suggests that late dose intensification in incomplete responders is not superior to the usually reported results obtained with standard regimens for the treatment of SCLC.