Chronic lymphocytic leukemia (CLL) in younger adults: a retrospective study of 133 cases.

Clinical and biological data have been evaluated, using both univariate and Cox's multivariate statistical analyses, in a series of 133 Chronic Lymphocytic Leukemia (CLL) patients with a mean age of 46.6 years (range 31-50). In univariate analyses, anemia (Hb less than 13 g/dl), peripheral blood (PB) lymphocytosis (greater than 40 x 10(9)/l) and bone marrow (BM) lymphocytosis (greater than 80 per cent) were shown to be of significant prognostic value. Multivariate analysis, through a forward stepwise procedure, showed that the most important and independent variable is the BM lymphocytosis. These results are different from those obtained in previous studies and particularly in a recent identical study performed by the same Cooperative Group on 1777 patients with a mean age of 64.2 years (Mandelli et al., 1987). No significance can be demonstrated in stratifying this series of younger patients according to different staging methods (Rai et al., 1975; Binet et al., 1981b; Mandelli et al., 1987). Therefore this population of CLL patients, with less than 50 years of age, has risk factors quite different from classical CLL. The results of the present study show that the diagnostic approach to B-CLL in younger adults must be more complete: using the common diagnostic criteria, established staging systems appear to be inadequate in this series of younger patients.