Nucleolus organizer regions (AgNORs) and total tumor mass are independent prognostic parameters for treatment-free period in chronic lymphocytic leukemia

The aim of our study was to evaluate whether the nucleolus organizer region s (AgNOR) of circulating lymphocytes in chronic lymphocytic leukemia (CLL) could predict the duration of the stable phase (treatment-free period) of t his disease. Age, sex, peripheral lymphocytes, hemoglobin, platelet count, Binet's stage, total tumor mass (TTM) and AgNOR pattern at diagnosis were a ssessed in 57 patients and compared with the time from diagnosis until pati ents fulfilled the criteria to start chemotherapy. In univariate Cox regres sion, Binet's stage, hemoglobin, number of peripheral lymphocytes, TTM and the percentage of lymphocytes containing one AgNOR cluster (circulating pro liferative fraction) had predictive value. In the multivariate Cox model, o nly TTM and the percentage of cells with one AgNOR cluster were independent factors predicting the duration of the stable phase. Repetition of these a nalyses in 500 data sets created by bootstrap resampling confirmed the resu lts, Summing up the percentage of lymphocytes with an AgNOR cluster and the TTM value, a simple prognostic index could be created to give information about the duration of the stable phase in CLL, (C) 2000 Wiley-Liss. Inc.