Relapse of chronic myeloid leukemia after allogeneic stem cell transplantation: outcome and prognostic factors. The Chronic Myeloid Leukemia Subcommittee of the GETH (Grupo Español de Trasplante Hemopoyético)

In order to analyze the outcome of patients with chronic myeloid leukemia (CML) who relapse after allogeneic stem cell transplantation (SCT), we investigated data from 107 patients reported to the Spanish Registry, GETH. In all, 93 (87%) patients were treated after relapse; 36 out of 49 that failed to achieve a response received a second relapse-treatment, and seven a third one. At the last follow-up, the number of patients in molecular or cytogenetic remission was 29 and 13, respectively. Overall survival and progression-free survival after relapse were 53.6% (95% CI: 42.9--64.2) and 52% (95% CI: 41-63) at 5 years, respectively. In multivariate analysis, survival was significantly related to CML phase at relapse (cytogenetic or chronic phase vs advanced phases) and time from transplant to relapse (1 vsor=1 year). Patients with no adverse factors had a better survival compared with patients with one or two adverse features (65 vs 35 vs 0%, respectively). We conclude that a significant proportion of CML patients that relapse after transplantation can regain complete and long-lasting remissions with one or more salvage therapies. Disease stage at relapse and time from transplant to relapse should be taken into account when comparing results of different salvage treatments.