Long-term outcome and prognostic factors of second allogeneic hematopoietic stem cell transplant for acute leukemia in patients with a median follow-up of ≥10 years

Second allogeneic hematopoietic stem cell transplantation (HSCT2) is a frequently used treatment option for relapse of acute leukemia after first allogeneic transplantation. Remission can be induced in selected patients, but data on long-term outcome and finally cure are limited. To estimate the long-term results of HSCT2, we retrospectively analyzed the course of 286 patients receiving myeloablative HSCT2 between 1985 and 2000, with a median follow-up of 11.3 years. Overall survival (OS) and leukemia-free survival (LFS) at 10 years from HSCT2 were 10±2 and 7±2%, respectively. Cumulative 10-year incidence of relapse and non-relapse mortality were 58±3% and 35±3%, respectively. CR at HSCT2, an interval from first transplant to relapse >10 months and TBI as part of the conditioning for HSCT2 favorably influenced LFS and OS. Patients with all three favorable factors had a 10-year OS of 36±10% and LFS of 25±9%, whereas patients showing no favorable factor had all died before year 5. Although retrospective, the long follow-up of this analysis supports the curative potential of alloHSCT2 in selected patients, who might be identified in advance, based on prognostic factors.