Allogeneic bone marrow transplantation in chronic myeloid leukemia. The clinical results and risk factors in 70 patients

BACKGROUND: The 10 year experience of a single center performing allogeneic bone marrow transplantation in 70 patients with chronic myeloid leukemia (CML) is analyzed. METHODS: Seventy patients transplanted for CML between November 1982 and October 1992 were evaluated. Fifty-two patients were in the first chronic phase (FC), 10 in an accelerated phase, 4 in blast crisis and 4 in the second chronic phase. The combination of cyclosporin and methotrexate was the most commonly used prophylactic schedule for graft versus host disease (GVHD) (60 cases) and T depletion was not performed in any case. The combination of cyclophosphamide (120 mg/kg) and total body irradiation was used in 48 patients with the remaining patients received busulfan (16 mg/kg) and cyclophosphamide (120 mg/kg). The estimation of survival was performed using the Kaplan-Meier limit product method. The prognostic factors influencing survival, disease free period and relapse were evaluated by Cox multivariate models of proportional risk. RESULTS: Actuarial survival at four years was 40% (95% Cl: 26-58%). Multivariate analysis selected variables associated with lower survival, the presence of acute GVHD (relative risk-RR-4.75), advanced disease phase (RR: 3.26) and age over 30 years (RR: 3.57). Eleven patients had relapsed. Multivariate analysis found the absence of chronic GVHD (RR: 5.3) and advanced phase (RR: 1.91) to be associated to a higher probability of relapse. In a separate analysis of the 48 patients transplanted in chronic phase who received cyclosporin and methotrexate, the disease free survival was longer for those under the age of 30 years (71.4% vs. 36%) without acute GVHD (68.8% vs. 39.6%) and those transplanted from a male donor (64.6% vs. 30%). CONCLUSIONS: Advanced phase of the disease, the presence of acute graft versus host disease and the age and female sex of the donor are the main factors associated to shorter survival in allogeneic bone marrow transplant for chronic myeloid leukemia. In contrast, the presence of chronic graft versus host disease decreases the possibilities of relapse.