Increased activity and improved outcome in unrelated donor haemopoietic cell transplants for acute myeloid leukaemia in Australia, 1992-2005.

BACKGROUND/AIM: Numbers of unrelated donor allogeneic haemopoietic cell transplants (HCT) for acute myeloid leukaemia have increased in Australia in recent years. The aims of this study were to investigate the components of this change and find contributing factors to changes in outcome.

METHODS

The study method was a retrospective analysis of 213 consecutive first unrelated donor HCT for acute myeloid leukaemia performed within Australia for adult patients during the years of 1992-1997 (n= 43) and 1998-2005 (n= 170).

RESULTS

The proportion of patients transplanted in first or second complete remission (CR) increased markedly from 21% in 1992-1997 to 52% in 1998-2005. The cumulative incidence of relapse at 1 year post HCT was significantly lower for the later cohort (22% vs 30%, P= 0.04) and for patients transplanted in CR compared with those not in CR (16% vs 31%, P= 0.01). The overall survival probability was significantly better at 5 years post HCT for patients transplanted in 1998-2005 compared with 1992-1997 (40% vs 21%, P= 0.04). Multivariate analysis identified five independent significant favourable factors for survival among the whole patient group: age under 40 years, transplant in CR1, CR2 or first relapse, patient CMV seronegativity, good performance status and year of transplant within 1998-2005.

CONCLUSION

The later cohort of patients had improved survival even after allowing for the effects of age, remission status and other factors, which suggests a general improvement in the safety of the procedure over time, particularly for patients in early disease stages at transplant.