Feasibility of allogeneic hematopoietic stem cell transplantation in advanced age.

Although it is known that increasing age is associated with increased morbidity and mortality in allogeneic transplantation (allo-HSCT), individualization of the process may allow to perform it in progressively older patients.This study analyzed the outcome of 97 patients older than 60 years with a first allo-HSCT performed at our institution between 2011 and 2019.Median age was 66 years (range 60-79) and 15.4% were older than 70 years. The most frequent diagnosis was acute leukemia (50.5%), and 58.8% received a myeloablative conditioning. With a median follow-up of 33.9 months (range 7.9-111.5), at 3-years overall survival (OS) was 50%; progression-free survival (PFS), 46%; cumulative incidence of relapse, 22%; and non-relapse mortality (NRM), 32%. There were no significant differences in OS (p = 0.415), PFS (p = 0.691), cumulative incidence of relapse (p = 0.357) or NRM (p = 0.658) between patients of 60-64 years (n = 37), 65-69 (n = 45) and ≥ 70 years (n = 15). No differences were observed either depending on the intensity of the conditioning regimen in terms of OS (p = 0.858), PFS (p = 0.729), cumulative incidence of relapse (p = 0.416) or NRM (p = 0.270).In conclusion, older adults can safely and effectively undergo allo-HSCT with proper patient selection and individualized transplantation procedures.

Cytoplasmic localization of wild-type survivin is associated with constitutive activation of the PI3K/Akt signaling pathway and represents a favorable prognostic factor in patients with acute myeloid leukemia.

Survivin is over-expressed in most hematologic malignancies but the prognostic significance of the subcompartmental distribution of wild-type or splicing variants in acute myeloid leukemia has not been addressed yet. Using western blotting, we assessed the expression of wild-type survivin and survivin splice variants 2B and Delta-Ex3 in nuclear and cytoplasmic protein extracts in samples taken from 105 patients at the time of their diagnosis of acute myeloid leukemia. Given that survivin is a downstream effector of the PI3K/Akt signaling pathway, survivin expression was also correlated with pSer473-Akt. Wild-type survivin and the 2B splice variant were positive in 76.3% and 78.0% of samples in the nucleus, cytoplasm or both, whereas the Delta-Ex3 isoform was only positive in the nucleus in 37.7% of samples. Cytoplasmic localization of wild-type survivin was significantly associated with the presence of high levels of pSer473-Akt (P<0.001). Inhibition of the PI3K/Akt pathway with wortmannin and Ly294002 caused a significant reduction in the expression of cytoplasmic wild-type survivin. The presence of cytoplasmic wild-type survivin and pSer473-Akt was associated with a lower fraction of quiescent leukemia stem cells (P=0.02). The presence of cytoplasmic wild-type survivin and pSer473-Akt were favorable independent prognostic factors. Moreover, the activation of the PI3K/Akt pathway with expression of cytoplasmic wild-type survivin identified a subgroup of acute myeloid leukemia patients with an excellent outcome (overall survival rate of 60.0±21.9% and relapse-free survival of 63.0±13.5%). Our findings suggest that cytoplasmic wild-type survivin is a critical downstream effector of the PI3K/Akt pathway leading to more chemosensitive cells and a more favorable outcome in acute myeloid leukemia.