Long-term survival benefit after allogeneic hematopoietic cell transplantation in chronic myelomonocytic leukemia

Abstract The critical question in the management of chronic myelomonocytic leukemia (CMML) is which patients may benefit from allogeneic hematopoietic cell transplantation (allo-HCT). Using ad hoc statistical analysis, we designed a multicenter retrospective study to determine outcomes in 261 patients ≤70 years at diagnosis who received allo-HCT (n=119) compared with patients who did not (n=142) according to the current CMML-specific prognostic scoring system (CPSS). Categorizing patients as lower (CPSS low/intermediate-1) and higher risk (intermediate-2/high) showed significantly improved outcome after transplant in higher risk patients, with a 37% reduced hazard for death. However, while higher CPSS was associated with worse outcome in the nontransplant group, the score was of limited utility for posttransplant risk stratification. This study may further support the potentially beneficial role of allo-HCT in terms of long-term survival in higher risk patients but also underlines the need for transplant-specific risk assessment. Recognizing limitations of retrospective comparisons, larger and prospective comparisons are needed to further refine the indication for allo-HCT and thus counseling of CMML patients.