Prognostic Factors and Scoring Systems in Chronic Myelomonocytic Leukemia: A Retrospective Analysis of 37 Patients

Main objective of this study was to evaluate hematological, clinical and demographic features of our chronic myelomonocytic leukemia (CMML) patients according to different classification systems and prognostic variables. Thirty-seven consecutive patients with CMML diagnosed between February 1994 and December 2005 were evaluated retrospectively. Male and female ratio was 29/8. The median age at diagnosis was 72. Median follow-up time for all patients was 12 months (1-119 months). 70.3% of patients were classified as CMML-MP, others were classified as CMML-MD type according to FAB. When they were reclassified according to WHO, 86.5% of them were CMML-I and 13.5% were CMML-II. Karyotyping analysis could be made in only 22 patients. Median laboratory values were as follows: hemoglobin (Hb) 9 g/dL (range 6.1-14 g/dL), white blood cell (WBC) count 9.7 x 10/L (range1.8-157 x 10/L), peripheral monocyte count 3.5 x 10 /L (range 1.2-50 x 10 /L), platelet count 85 x 10/L (range 6-992 x 10 /L). Splenomegaly was observed in 11 patients (29.7%). 14 patients (37.8%) developed AML after a median time of 11 months (1-90 months) and survived a median of 1.5 months after leukemia transformation. The overall survival (OS) was 12 months (MD: 12 months, MP: 25 months, p= 0.3). International Prognostic Scoring Sytem (IPSS) could be applied to only 13 CMML-MD patients (WBC < 12 x 10/L). Patients were also assessed using previously published scoring systems. Significant differencies between risk groups were found in case of OS (Modified Bournemouth score: p= 0.039, Duesseldorf score: p= 0.01, IPSS: p= 0.003). In multivariate analysis, only hemoglobine (< 10 g/dL) and bone marrow blast percentage (≥ 10%) have been found to have a prognostic value (p= 0.03, p= 0.002). Although use of current prognostic scoring systems is encouraging in CMML more reliable disease spesific prognostic factors are needed for clinical decision making.