Background & objective: Chronic myelogenous leukemia (CML) is a malignant hematological disease.CML patients are commonly treated with hematopoietic stem cells transplantation (HSCT). This study was designed to evaluate the effect of HSCT on the patients with CML.
Methods: Forty-four patients with CML were treated by HSCT, including 8 cases treated with purging autologous transplantation, 30 cases with related donor allogeneic HSCT (allo-HSCT), and 6 cases with unrelated donor allo-HSCT. The conditioning regimen was TBI (total-body irradiation)+CY (CTX) protocol in 31 patients and modified BuCY (hydroxyurea, busulfan, Ara-C, CTX) protocal in 12 patients, and MACC (Melphalan, Ara-C, CTX and CCNU) protocol in one patient. CsA (cyclosporine) and MTX were used in the patients with related donor allo-HSCT, and CsA and MTX added to mycophenolate mofetil (MMF) and antithymocyte globulin (ATG) were used in the patients with unrelated donor all-HSCT for graft versus host disease (GVHD) prophylaxis. Otherwise, CsA was only used in the patients with accelerated phase(AP) and blast crisis(BC) for GVHD prophylaxis. Kaplan-Meier survival analysis model was used to estimate the overall survival (OS) and the disease-free survival (DSF) at 5 years after transplantation.
Results: Eight patients with autologous transplantation, except one case died of transplantation-related-complication, obtained part or complete cytogenetic remission within 3 months after transplantation. One patient, who was BC and obtained complete remission (CR) in hematology before transplantation,obtained complete molecular remission for 81 months after autologous transplantation. All patients obtained CR, except one patient died of hepatic veno-occlusive disease (VOD) and one case did not obtained CR, in 36 patients with allo-HSCT after transplantation. The incidence of infection and VOD during transplantation were 38.6% and 9.1%, respectively. The incidences of hemorrhagic cystitis (HC) and cytomegalovirus (CMV) pneumonia after transplantation were 15.9% and 11.4%, respectively. VOD, HC, and CMV pneumonia did not occur in the patients with autologous transplantation. The incidence of acute GVHD in the patients with related and unrelated donor transplantation were 40.0% and 33.3%, respectively. The incidence of chronic GVHD was 43.4% in the patients with related donor transplantation. The rates of transplant-related mortality (TRM) in the patients with autologous and allogeneic transplantation were 12.5% and 16.7%, respectively. The rates of relapse in patients with autologous and related donor transplantation were 37.5% and 13.3%, respectively. The DFSs at 5 years in patients with autologous and related donor transplantation after transplantation were 18.7% and 53.7%, respectively. The DFS at 5 years in patients with CP (chronic phase) or AP and BC before transplantation were 66.4% and 26.7%, respectively.
Conclusion: all-HSCT shows higher clinical cure rate to CML patients with CP. CsA+MTX+MMF+ATG protocol is more effective for acute GVHD prophylaxis and can decrease the incidence and severity of acute GVHD in patients with unrelated donor transplantation. Autologous transplantation with bone marrow purged can prolong the survival time and a few patients may be cured with autologous transplantation in CML.