The significance of the bone marrow biopsy pattern in chronic lymphocytic leukemia: A prognostic dilemma

Although bone marrow biopsy pattern (BMBP) has long been suggested to be an independent prognostic factor in chronic lymphocytic leukemia (CLL), confl icting reports continue to appear in the literature. To investigate this is sue we retrospectively reviewed 70 CLL patients who had undergone bone marr ow biopsy at the time of diagnosis in a multivariate Cox regression analysi s together with other prognostic factors. There were 51 (72.8%) males and 1 9 (27.2%) females with a median age of 60 years (range, 38-77). The median follow-up time was 24 months (range, 1-76), and median survival was 44 mont hs. Thirtyfour patients (48.6%) had diffuse and 36 patients (51.4%) had non diffuse BMBP (14 nodular, 11 interstitial, and 11 mixed). The median surviv al for diffuse and nondiffuse BMBP groups were 17 and 53 months, respective ly (P = 0.05). Sixteen patients (22.9%) had stage A, 28 (40.0%) stage B, an d 26 (37.1%) stage C disease according to the Binet system, and four patien ts (5.7%) had low-risk, 39 (55.7%) intermediate-risk, and 27 (38.6%) high-r isk disease according to the modified Rai staging system. The difference be tween the median survivals of patients in different stages was statisticall y significant (P < 0.0001). The BMBP and staging systems that are thought t o be significant predictors of prognosis were used to build a multivariate Cox proportional hazard model. BMBP was not found to add additional informa tion to the prognostic value of the staging systems. Our results underline two points: first, the significance of BMBP must be investigated in multiva riate analysis including the stage, and second, BMBP is not a dynamic progn ostic parameter, it is an index of tumor burden and does not add any progno stic information beyond that provided by clinical stage. (C) 1999 Wiley-Lis s, Inc.