Impact of disease status at allogeneic stem cell transplantation on adolescent and young adult patients with early T‐cell precursor acute lymphoblastic leukemia

Abstract

Early T‐cell precursor (ETP) acute lymphoblastic leukemia (ALL) is an aggressive subset of T‐cell ALL, and the role of allogeneic hematopoietic stem cell transplantation (allo‐HSCT) in adolescent and young adult (AYA) patients has not been sufficiently described. We retrospectively analysed the data of 30 AYA patients (19 in first complete remission [CR1], 3 in CR2, and 8 with active disease) with ETP‐ALL who underwent myeloablative allogeneic hematopoietic stem cell transplantation (allo‐HSCT) from HLA‐matched related, n = 2, unrelated, n = 5, or HLA‐haploidentical related, n = 23 donors with an emphasis on the impact of disease status on the outcomes of transplant. The stem cell source was unmanipulated G‐CSF mobilized bone marrow or peripheral blood stem cells. All patients achieved neutrophil engraftment with full donor chimerism. The cumulative incidences of grade II to IV acute graft‐versus‐host disease (GVHD) and chronic GVHD at 2 years were 37% and 33%, respectively. Overall, 16 patients died. The causes of death were relapse (8 patients), infection (4 patients) and GVHD (4 patients). The estimated 2‐year overall survival (OS) and leukemia‐free survival (LFS) for the whole cohort were 47.8% and 46.2%, respectively. Patients transplanted in CR1/2 had significantly better 2‐year OS and LFS than patients with active disease (61.7% vs. 12.5%, p = 0.02; and 58.3% vs. 12.5%, p = 0.04, respectively). There was a trend toward an inferior OS rate in those patients in CR1 with chemoresistance or in CR2 compared with patients in CR1 with chemosensitivity, although this did not reach statistical significance. Our data support allo‐HSCT, especially from HLA‐haploidentical donors as an effective therapeutic strategy in AYA patients with ETP‐ALL and disease status was significantly associated with survival in these patients.