Unrelated donor bone marrow transplantation as treatment for chronic myeloid leukemia: the Spanish experience

Background and Objectives. To analyze the results of unrelated bone marrow transplantation (UDBMT) as treatment for chronic myeloid leukemia (CML) In, Spain, Designs and Methods. Eighty-seven consecutive UDBMT performed in 9 centers between October 1989 and February 1998 were evaluated. This represents more than 95% of UDBMT for CML performed formed in adult transplant centers in Spain during this period. The patients' median age was 31.5 years (range 12 -49), The median Interval from CML. diagnosis to UDBMT was 30 months (range , 3-160). Seventy-nine percent of transplants were per formed during the fi rst chronic phase (1CP), Results, Actuarial probability of survival and disease;free survival at 4 y ears for the whole series was 24% (95% confidence interval [CI]: 14%-34%) a nd 20% (CI: 10%-30%) respectively. The cumulative Incidence of relapse and transplant-related mortality (TRM) was 7% (CI: 4%-10%) and 71% (CI: 60%-82% ), respectively. The main causes of death were graft failure (n=7), infecti on (n=23), and graft-versus-host disease (GVHD) (n=25), The actuarial proba bility of acute GVHD grade Ii-IV and grade III-IV was 56% (CI:46%-66%) and 36% (CI: 26%-36%), respectively. The cumulative Incidence of extensive chro nic GvHD was 18% (CI: 9%-27%), Univariate analyses showed that the pre-tran splant factor with the highest influence on survival was disease status at transplant (30% in 1CP vs. 0% in advanced phases; p=0.0001). ether pre-tran splant factors influencing survival among patients in 1CP were: patient's a ge (older than 30 years 11% vs. 48%), interval diagnosis-transplantation (l onger than 2 17% vs. 55%), donor type (HLA, a, DRB1 identical vs, 25%), CMV serologic status (donor recipient negative 63% vs. 24%), year of trans(bef ore plantation (before 1995 19% vs. 40%), and conditioning regimen (cycloph osphamide plus total body radiation 40% vs, 16%), The main risk factors had a cumulative effect on survival. Thus, probability of survival ranged from 66% (CI: 39%-93%) In patients in 1CP, under 40 years of age, transplanted from an HLA, A, B, DRB1 identical donor during the first two years after di agnosis, to 0% in those with three or mom risk factors. Interpretation and Conclusions. This experience shows that UDBMT used to ha ve a high TRM that has progressively decreased along the years. At the pres ent time, the results are encouraging, particularly when UDBMT Is performed under favorable conditions (C) 2000 Ferrata Stortl Foundation.