Efficacy Of Allogeneic Hematopoietic Stem Cell Transplantation For Chronic Myelomonocytic Leukemia

Objective To investigate the outcomes of allogeneic hematopoietic stem cell transplantation(allo-HSCT)for chronic myelomonocytic leukemia(CMML)and to analysis risk factors of prognosis.Methods A total of 22 patients with CMML,who received allo-HSCT in transplant center of Institute of Hematology and Blood Disease Hospital from November 2009 to February 2019,were retrospectively analyzed.The overall survival(OS)rate,disease-free survival(DFS)rate,hematopoietic reconstitution,graft-versus-host disease(GVHD),infection,recurrence and splenomegaly were analyzed.The statistics was performed by software SPSS17.0.Results The median age of the 22 patients was 44(24-59),including 11 males and 11 females.Eleven patients(50.0%)had palpable splenomegaly(SPM)before allo-HSCT.Hematopoiesis reconstitution was not achieved in 2 recipients because of early death after transplantation.Neutrophil engraftment was achieved in 20 recipients,and the median time of neutrophil engraftment were 14(11-24)days.Neutrophil engraftment and platelet engraftment was achieved in 18 recipients,and the median time of patelet engraftment were 16(12-70)days.Nine patients occurred acute GVHD(grade 1 in 6 patients、grade 2-4 in 3 patients),and 8 patients occurred chronic GVHD(extensive in 5 patients).The cumulative incidence of acute GVHD and chronic GVHD was 46.3%±12.4%and 45.0%± 11.1%,respectively.After the median follow-up of 32.5(0.5-80)months,the 3-year overall survival(OS),disease free survival(DFS),cumulative incidence of relapse(CIR)and non-relapse mortality(NRM)were 59.7%±11.2%,37.6%±11.4%,38.5%±14.4%,38.6%±11.8%,respectively.Univariate analysis showed that OS rate was significantly correlated with disease diagnosis(the OS rate of CMML transferred to AML patients was only 16.7%,significantly lower than that of CMML-1 and CMML-2 patients 75.0%,P=0.017)and bacteremia(the OS rate of patients with bacteremia was 0%,significantly lower than that of patients without bacteremia 72.2%,P=0.001).The OS rate of patients with leukemia cell less than 10%(70.6%)was higher than that of patients with leukemia cell more than 10%(20.0%)in bone marrow before transplantation,which was close to significant difference(P=0.062).The DFS rate was significantly correlated with whether bacteremia occurred(the DFS rate of patients with bacteremia was 0%,significantly lower than that of patients without bacteremia 55.6%,P=0.005),whether extensive chronic GVHD occurred(the DFS rate of patients with extensive chronic GVHD was 80.0%,significantly higher than that of patients without extensive chronic GVHD 42.9%,P=0.045).The DFS rate of CMML-1 and CMML-2 patients was 56.3%,higher than that of patients with CMML transferred to AML 16.7%,which was no significant difference(P=0.119).Eleven patients(50.0%)had palpable splenomegaly(SPM)before allo-HSCT,and 7 patients died;9 patients were diagnosed with ultrasound after transplantation,and 5 patients with no significant reduction of the spleen were all dead,4 patients with significant reduction of the spleen were all alive.Conclusion Allo-HSCT can improve the survival of patients with CMML,and is a effective therapy for CMML.Transplantation in the early stage of CMML disease,effective prevention and treatment of bacteremia can improve the survival of allo-HSCT in CMML patients.In addition,palpable splenomegaly before transplantation and no significant reduction after transplantation seems to be a negative factor in patients.