Comorbidities Index Is Not Predictive of Treatment Related Mortality in Patients (pts) Older Than 60 Years Treated with Reduced Intensity Conditioning and Allogeneic Stem Cell Transplantation (RIC-ALLO).

Allogeneic stem cell transplantation (ALLO) is the only curative therapy for many hematological malignancies. For many of these diseases, the median age at diagnosis is around the sixth decade of life, precluding myeloablative ALLO (MAC-ALLO). RIC-ALLO is less toxic and it has been performed in elderly pts, mainly affected by acute leukemia. Finally, comorbidities index seem to predict treatment related mortality (TRM) and overall survival (OS).

From 2001 and 2008, 67 pts older than 60 years (median age 63 y, range 60-70) received RIC-ALLO. Diseases were: acute myeloid leukemia 45%, multiple myeloma 18%, chronic lymphocytic leukemia 12%, non-Hodgkin lymphoma 10%, myelodysplasia 6%, plasmacellular leukemia 3%, others 6%. Disease status at RIC-ALLO was: complete remission 54%, partial remission 16%, and active disease 30%. RIC consisted of fludarabine-based with thymoglobulin 64%, or low-dose TBI-based 36%. Donors were: HLAid sibling 73%, matched unrelated 21%, and cord blood 6%. Previous autologous transplant was performed in 59% of pts. The median number of CD34+ and CD3+ cells infused was 5 (range 1-9.4) and 296 (range 84-704), respectively. Karnofski score was 60-80% in 25% and 90-100% in 75%; HCT-CI was 0 in 33%, 1-2 in 33%, and more than 3 in 34%; PAM score was 8-16 in 9%, 17-33 in 65%, 24-30 in 22%, and more than 31 in 3%; EBMT score was 2 in 22%, 3 in 36%, 4 in 28%, more than 5 in 12%.

The median follow-up was 22 months. The 2-y OS and PFS were 66.8% (IC95 [55.5-80.4]) and 52.4% (IC95 [39.5-69.5]), respectively. Grade II-IV acute graft versus host disease (aGVHD) and chronic GVHD (cGVHD) incidence were 49% and 43%, respectively. Early infections were fever of unknown origin in 42% of pts, bacterial infection in 6 cases, pneumonia in 8, and viral infections in 14. The early infection-related mortality was null. Late infections were bacterial in 3 cases, pneumonia in 1, viral infections in 6, and candidemia in 1. Seven pts died from late infective complications. Overall, the cause of death was toxicities in 18 pts and disease progression in 6 pts. The 100-d and 1-y TRM were 6.35% (IC95 [0.278-12.4]) and 24.2% (IC95 [12.9-35.4]), respectively.

In univariate analysis, HCT-CI, EBMT score, and PAM score did not influence TRM or OS. Furthermore, age (60-65 vs 66-70) was not related to TRM.

The aim of this retrospective study was to verify if TRM was excessively high in elderly pts, affected from several haematological diseases and receiving ALLO from different donors and after different RIC. A secondary objective was to evaluate if several comorbidities index could predict TRM and OS. This heterogeneity should be regarded as a more realistic view of general population.

TRM was acceptable and not different when compared to younger pts as reported in literature. Furthermore, neither comorbidities index nor age help segregate a group of pts with different TRM.

No relevant conflicts of interest to declare.