Clinical Characteristics And Survival Analysis Of 37 Patients With Chronic Myelomonocytic Leukemia

Objective:To investigate the clinical characteristics,survival,prognostic factors and therapeutic response to hypomethylating agent(HMA)of patients with chronic myelomonocytic leukemia(CMML).Methods:The clinical data of 37 newly diagnosed patients with CMML who were admitted to the Second Hospital of Shanxi Medical University from January 1,2013 to July 1,2021was analyzed retrospectively.We summarized their clinical characteristics and analyzed the efficacy of HMA.Kaplan-Meier and Log-rank test were used for univariate survival analysis and Cox proportional risk regression model was used for multivariate analysis.Results:The median age at diagnosis was 67 years old.The main initial clinical manifestations include fatigue,bleeding,abnormal blood routine and fever.Most patients had splenomegaly.According to FAB classification,there were 6 cases(16%)of myelodysplastic CMML and 31 cases(84%)of myeloproliferative CMML.According to WHO classification,8 cases(22%)belonged to CMML-0,9 cases(24%)to CMML-1and 20 cases(54%)to CMML-2.At the time of diagnosis,the median white blood cell count was 32.84×10~9/L,the median hemoglobin(Hb)was 101 g/L,the median platelet count was 65×10~9/L,the median absolute monocyte count was 9.53×10~9/L,the median absolute neutrophil count(ANC)was 11.29×10~9/L and the median lactate dehydrogenase(LDH)was 374 U/L.Cytogenetic abnormalities were found in 13%(4/31)patients and gene mutations were identified in 92%(11/12)patients,including ASXL1,NRAS,TET2,SRSF2 and RUNX1.The median OS was 12 months.Among the 6patients who were treated with at least 4 courses of HMA and could be evaluated for efficacy,2 patients achieved complete remission,1 patient achieved partial remission and2 patients achieved clinical benefit.The median OS and median leukemia free survival(LFS)of patients treated with HMA were 15.2 and 14.4 months,respectively,which were not significantly longer than those of patients treated without HMA.Univariate analysis showed that Hb<100 g/L,ANC≥12×10~9/L,LDH≥250 U/L and peripheral blood(Pb)blasts≥5%were significantly associated with poor OS(P<0.05).WHO classification CMML-2,Hb<100 g/L,ANC≥12×10~9/L,LDH≥250 U/L and Pb blasts≥5%were significantly associated with poor LFS(P<0.05).Multivariate analysis showed that ANC≥12×10~9/L and Pb blasts≥5%were significantly associated with poor OS and LFS(P<0.05).Conclusion:CMML has high heterogeneity in clinical characteristics,genetic changes,prognosis and treatment response.HMA could not significantly improve the survival of CMML patients in this study.ANC≥12×10~9/L and Pb blasts≥5%are independent prognostic factors of poor OS and LFS in patients with CMML.