Relapse risk assessment of transplantation for patients with chronic myeloid leukaemia

Objective To analyse the risk factors of relapse before bone marrow transplantation (BMT) and to present the prognostic information as good as possible. Methods A total of 3142 patients, who underwent the allogeneic blood or bone marrow transplantation between 1989 and 1997 and were documented in the European Group for Blood and Marrow transplantation (EBMT), were included. Six possible risk factors including type of donor, stage of disease, age, gender, donor-recipient sex combination and the waiting time from diagnosis to transplation of relapse were considered. The time to relapse was analysed by Kaplan-Meier curves and Cox regression with stratification on prognostic factors that did not satisfy the Proportional Hazard Assumption. Results An amount of 447 patients relapsed out of all 3142 patients. The relapse rate was 14.2%. Type of donor and stage of disease showed a clear prognostic effect, but failed the proportional hazard assumption. Therefore, the data were stratified on the combination of type of donor and stage of disease. Within these strata an additional significant effect of age could be observed. Relative risk of age, 40 vs age < 40 was 1.32 (95% confidence interval 1.09 - 1.59). The prognostic model is summarized graphically. Conclusions The combination of type of donor, stage of disease and age of recipient at transplantation are important prognostic factors for relapse after BMT.