Two groups of chronic myelomonocytic leukaemia: myelodysplastic and myeloproliferative. Prognostic implications in a series of a single center

Abstract

The clinical records of 70 patients seen at our hospital between 1976 and 1998 and diagnosed as suffering from chronic myelomonocytic leukaemia (CMML) were reviewed in order to confirm the validity of the classification into two forms of disease that the French-American-British Co-operative Leukaemia Group (FAB) proposed in 1994: myelodysplastic (MD) and myeloproliferative (MP), depending on the peripheral white blood cell count (WBC) (less or more than 13 x 10(9)/l, respectively). After the rejection of incomplete records and lost to follow up patients, our study population consisted of 49 records. Our results confirm that, even though this classification is useful in order to separate two classes of patients, it is not enough to predict the prognosis in an accurate manner. A lot of studies have tried to find some prognostic factors, but the results have been discordant. The multivariate analysis of our group of patients showed three prognostic factors: serum lactate dehydrogenase (LDH) >1.5 times normal level, blasts in bone marrow >5%, and peripheral blood leukocytes >10 x 10(9)/l. A second multivariate analysis led us to distinguish two groups: high risk (2-3 risk factors) and low risk (0-1 risk factors) (median survival 7 and 44 months, respectively) with a very high statistic significance (P<0.0001). This score should be applied to other series of CMML patients in order to confirm its validity.