Dysplastic versus proliferative CMML--a retrospective analysis of 91 patients from a single institution

In chronic myelomonocytic leukemia (CMML) segregation of two subtypes has been suggested depending on WBC count-myelodysplastic (MD-CMML) and myeloproliferative (MP-CMML). In a retrospective analysis of 91 (60/31) previously untreated CMML patients, we compared the presenting clinical, haematological, laboratory and bone marrow features and examined the clinical impact of this reclassification. LDH values and bone marrow cellularity were significantly increased in MP-CMML. Median survival was significantly longer for patients with MD-CMML, progression rate was higher for MP-CMML. Patients with MD-CMML had longer median preleukemic duration; after transition to AML, MP-CMML patients had longer median survival. In MDS phase anemia was more common in MP-CMML and thrombocytopenia more common in MD-CMML whereas transfusion rates showed no difference. Evaluation of prognostic scoring systems for both groups confirmed that patients' characteristics and outcome could be well compared. Our data suggest that segregation into MD-CMML and MP-CMML is justified.