Donor compatibility and performance status affect outcome of allogeneic haematopoietic stem cell transplant in patients with relapsed or refractory acute myeloid leukaemia.

We retrospectively analysed 78 patients with relapsed (n = 38), primary refractory (n = 34) or untreated (n = 6) acute myeloid leukaemia (AML) who underwent allogeneic HSCT at our Institution between 2002 and 2011, to verify outcome and to identify factors that can affect long-term outcome. Myeloablative conditioning regimens were used in 48 patients (24 siblings, 24 matched unrelated donor (MUD)), while 30 patients (18 siblings, 12 MUD) received reduced-intensity conditioning. Acute graft versus host disease (GVHD) developed in 37 (47 %) patients, while chronic GVHD occurred in 19 of the 65 evaluable patients (29 %). With a median follow-up time of 5 years, 13 of 78 patients (17 %) are alive and in complete remission (CR), while 64 have died. Cause of death was disease recurrence in 37 patients (58 %), infection in ten patients (16 %) and GVHD in six (9 %). One-year non-relapse mortality was 35 %. In multivariate analysis, performance status ≥80 % WHO and a full-matched donor were associated with a better outcome: these two variables allowed for risk stratification, identifying three groups with significantly different survival after transplant (P = 0.0001). Considering post-transplant variables, only CR at recovery and development of cGVHD were correlated with a longer survival. Our data confirm the capacity of allogeneic transplant to prolong survival in a significant proportion of extremely high-risk AML patients.