Allogeneic hematopoietic stem cell transplantation in the elderly. Predicting the risk for non relapse mortality

We have retrospectively reviewed 137 medical records of patients older than 50 years receiving an allogeneic hematopoietic stem cell transplantation (HSCT) between January 1997 and July 2013. Median follow up was 1.3 years. Sex, age, diagnosis, disease stage, comorbidities (according to HCT-CI score), type of donor, histocompatibility, conditioning regimen and graft-versus-host disease (GVHD) prophylaxis were evaluated. The incidence and severity of acute and chronic GVHD, overall survival (OS), disease free survival (DFS), non-relapse mortality (NRM) and relapse were investigated according those variables. Acute GVHD incidence was 41% (7.3% GIII-IV). Patients with acute myeloid leukemia had lesser aGVH GII-IV (14% vs. 35%, p<0.01) comparing to the entire population. Extensive cGVHD incidence was 9.4%. Global OS 1-3 years was 44-20%, DFS 33-20%, relapse 35-41% and NRM 36-43% respectively. The presence of comorbidities showed a significant increase in NRM (CT-CI 0 vs. 1 vs ≥2: 1-3 years 17-24% vs. 40-46% vs. 45-67%, p=0.001, MA HR 2.03, CI 95% 1.02-5.29), as well as cyclosporine vs. tacrolimus (1-3 years 47-53% vs. 25-36%, p=0.01). Tacrolimus patients had higher 1-3 years OS (49-25% vs. 31-13%, p=0.01) and DFS (41-26% vs. 20-11%, p<0.01). Age, type of donor and myeloablative conditioning showed no significant differences in any outcome. Allogeneic HSCT is a valid therapeutic option for older patients in Argentina. The main risk factor for a significantly increased NRM and a trend to inferior OS was the number of comorbidities. Age was not a factor for a worse result. The other factor having a significant effect in better outcome was tacrolimus administration.