BONE-MARROW HISTOLOGIC PATTERN - THE BEST SINGLE PROGNOSTIC PARAMETER IN CHRONIC LYMPHOCYTIC-LEUKEMIA - A MULTIVARIATE SURVIVAL ANALYSIS OF 329 CASES

Abstract

The prognostic value of bone marrow (BM) histologic patterns in chronic lymphocytic leukemia (CLL) was demonstrated. In order to investigate whether such a value is independent of other prognostic parameters, a multivariate survival analysis (Cox''s regression model) was undertaken in a series of 329 CLL patients in whom a BM was performed. The following binary variables were included in the analysis: age (more than 60 yr), lymphadenopathy (more than 2 areas involved), splenomegaly, hepatomegaly, absolute lymphocyte count (more than 30,000 .mu.l), anemia (Hb < 10 g/dl), thrombocytopenia (less than 100,000 .mu.l, and BM pattern (diffuse vs. nondiffuse). Three variables entered the regression at significant level: BM pattern (P < 0.001), anemia (P < 0.001), and hepatomegaly (P = 0.03). The model was also tested by expressing the variables in a continuous way when possible. Again, BM pattern entered first in the regression (P < 0.001), followed by the hepatomegaly (P = 0.002), Hb level (P = 0.02), and lymphadenopathy (P = 0.04). When both the binary and the continuous models were tested separately in 227 patients with BM as initial staging procedure and in 102 patients in whom this was performed later during the course of the disease, in all instances, BM pattern entered first in the regression at a highly significant level. BM histologic pattern appears to be a better single prognostic parameter than any 1 of the variables employed in current clinical staging systems. A combined clinicopathologic system incorporating the BM pattern, together with the usual clinical variables, is presented.