Prognostic factors in chronic myeloid leukemia: allografting.

Risk assessment for allografting differs from that for conventional therapy mainly because the transplant intervenes far from initial diagnosis and generates a new source of morbidity and mortality, graft-versus-host disease (GvHD). Major well-defined pre-, peri- and post-transplant risk factors influence two endpoints: transplant-related mortality (TRM) and relapse incidence (RI), which in turn determine the principal outcomes-leukemia-free survival (LFS) and survival. Some factors have concordant effects on both endpoints, like disease stage. Other risk factors have divergent effects: histocompatibility, intensity of conditioning, or GvHD prevention. The impact of risk factors with divergent effects differs in various time periods post-transplant. The main pretransplant factors are disease stage, patient age and sex, donor-recipient sex combination, histocompatibility, and time from diagnosis to transplant. The primary peritransplant factors are the intensity of conditioning and of GvHD prevention. The main post-transplant factor is severity of acute and chronic GvHD. Determination of the risk profile for an individual patient is reliable and should form an integral part of pretransplant counseling. The management strategies for patients with high-risk disease and low TRM risk profiles and for patients with low-risk disease and high TRM risk profiles should be different.