Autologous stem cell transplantation in chronic myeloid leukemia

Autografting was first attempted for patients with chronic myeloid leukemia (CML) in transformation in order to restore a second chronic phase (CP). The principal rationale for autografting in CP resides on the reduction of the tumor burden and the number of leukemic cells at risk of developing blastic transformation, and the possibility of eradicating already mutated cells. In a European Group for Blood and Marrow Transplantation (EBMT) Registry survey, patients with CML in CP, undergoing autologous stem cell transplantation (auto-SCT) for the first time, had an overall survival of 65% at 5 years from transplant with more than 50% of all patients remaining in CP. The main point made by this retrospective study was that in patients refractory to interferon-alpha (IFN), 70% achieved a cytogenetic response post autografting, which was complete or major in 31%. Since the advent of imatinib, autografting in CML has experienced a substantial decline. Theoretically, there are several possible ways of using auto-SCT in combination with imatinib: (1) to reverse resistance to imatinib; (2) to eliminate a Ph-positive clone bearing a BCR-ABL kinase domain mutation; and (3) to reduce the level of residual disease after a cytogenetic response to imatinib in patients in whom Ph-negative cells had been harvested. The exact role of auto-SCT in the present management of CML remains unanswered.