Use of cytosine arabinoside and total body irradiation as conditioning for allogeneic marrow transplantation in patients with acute lymphoblastic leukemia: a multicenter survey.

We report the experience of 14 centers which have used the combination of cytosine arabinoside (ara-C; 24-36 g/m2) and total body irradiation (TBI) to prepare 213 patients with acute lymphoblastic leukemia (ALL) for allogeneic BMT. The overall 3-year disease-free survival (DFS) probability is 38% (95% CI: 31-45%); 75 patients died of complications and 51 relapsed. Multivariate analysis identified three factors independently associated with outcome: age, remission/relapse status and patient-donor relationship. The 3-year DFS probability is 52% (41-63%) for the 106 patients aged 0-11 and 25% (16-33%) for the 104 aged 11+ years; the DFS probability was 54% (34-74%), 41% (32-49%) and 19% (5-33%) for those in first remission, later remissions and relapse respectively. Older patients suffered both more toxic deaths and more relapses than young ones. No other covariate was found to predict for outcome. The results using ara-C-TBI are similar to those achieved using cyclophosphamide plus TBI to prepare ALL patients for BMT, perhaps because a seemingly lower relapse rate is offset by more toxic deaths particularly in older patients. Therapeutic trials should focus on reducing toxicity while maximizing antileukemic efficacy, and should stratify for patient and disease-related factors.