[Comparison of the long term results between two conditioning regimens MCC and BuCy in chronic myelocytic leukemia after allogeneic stem cell transplantation].

Objective: To observe and evaluate the long term survival of patients with chronic myelocytic leukemia transplanted with MCC and BuCy conditioning regimens.

Methods: Fourteen cases were treated with MCC regimen (Melphanlan 170 mg/m2 x d x 1, MeCCNU 400 mg/m2 x d x 1, CTX 60 mg/kg x d x 2) and the median follow up time was 6 years; 16 cases were treated with BuCy regimen (Busulfan 4 mg/kg x d x 4, CTX 60 mg/kg x d x 2) and the median follow up time was 4 year.

Results: All the patients were engrafted successfully. 4 of 10 patients examined in MCC group showed mixed chimerism at day 100 after transplantation, whereas only 1 of 12 patients examined in BuCy group showed mixed chimerism. All the patients became complete donor source later without any DLI. The 5-year disease-free survival rate was 71.4% for MCC group and 62.5% for BuCy group. The transplant related mortality and relapse rate were 21% and 7% for MCC group, whereas those were 25% and 12% for BuCy group, respectively. The regimen related toxicity was relatively lower in MCC group and the median duration of hospitalization was 39 days (25-55 days) for patients with MCC regimen, and 55 days (39-90 days) for BuCy regimen.

Conclusion: MCC regimen has a partial ablative effect on CML and the long term disease-free survival is the same as that of BuCy regimen. In regard to the cost-effect efficacy, MCC regimen has a substantial advantage over BuCy regimen.