LONG-TERM RESULTS AFTER ALLOGENEIC BONE-MARROW TRANSPLANTATION FOR CHRONIC MYELOGENOUS LEUKEMIA IN CHRONIC PHASE - A REPORT FROM THE CHRONIC LEUKEMIA WORKING PARTY OF THE EUROPEAN GROUP FOR BLOOD AND MARROW TRANSPLANTATION

The purpose of this study was to determine the long-term results of al logeneic bone marrow transplantation for chronic myeloid leukemia. A r etrospective analysis was carried out of the outcome of 373 consecutiv e transplants performed at 38 European institutions between 1980 and 1 988 and reported to the registry of the European Group for Blood and M arrow Transplantation. All transplants were carried out for first chro nic phase of chronic myelogenous leukemia using unmanipulated marow ce lls from HLA-identical sibling donors. The probability of survival and leukemia-free survival at 8 years were 54% (95% CI: 49-59) and 47% (9 5% CI: 41-52) respectively. The probabilities of developing acute GVHD (II-IV) at 100 days and chronic GVHD at 4 years after transplant were 47% (95% CI: 41-53) and 52% (95% CI: 46-58) respectively. The probabi lities of transplant-related mortality and leukemic relapse 8 years af ter BMT were 41% (95% CI: 36-48) and 19% (95% CI: 14-25), respectively . Transplant within 12 months of diagnosis was associated with reduced transplant-related mortality (34 vs 45%, P = 0.013) and resulted in i mproved leukemia-free survival (52 vs 44%, P = 0.03). The probability of relapse was significantly reduced in patients who developed chronic GVHD (RR = 0.33, P = 0.004). The probability of relapse occurring mor e than 2 years after transplant was increased more than five-fold in p atients transplanted from a male donor (RR = 5.5, P = 0.006). Sixty-se ven patients in hematologic remission were studied for residual diseas e by two-step RT/PCR for BCR-ABL mRNA and 61 (91%) tested negative. We conclude that bone marrow transplantation can induce long-term surviv al in approximately one-half of CML patients; the majority of survivor s have no evidence of residual leukemia cells when studied by molecula r techniques. The probability of late relapse is increased with use of a male donor.