Clinical tumor cell distribution pattern is a prognostically relevant parameter in patients with B-cell chronic lymphocytic leukemia

Background and Objectives. B-cell chronic lymphocytic leukemia (B-CLL) cell s are variably distributed among the major lymphoid compartments contributi ng to the heterogenous clinical presentation and course of this disease. In order to evaluate this variable distribution we propose a model for its cl inical assessment. Design and Methods. We introduce the model for tumor distribution (TD) assessment base d on the total tumor mass (TTM) scoring system, where TD value represents p ercentage of total tumor mass infiltrating peripheral blood and bone marrow (TD=TM1/TTM). TD in B-CLL can be categorized into 3 subgroups: pure leukem ia when TD=100%, predominantly leukemia if TD=50-99% and predominantly lymp homa when TD < 50%. Results. Among 341 B-CLL patients there were 22.6%, 55.1%, 22.3%, pure leuk emia, predominantly leukemia and predominantly lymphoma cases, respectively . The TD parameter was strongly associated in univariate analysis with TTM size, Rai and Binet stages, spleen size and beta (2) microglobulin. TD was associated with response to therapy and survival, with higher TD values tra nslating into higher response rates and longer survival. However, in univar iate and multivariate Cox analysis TD displayed a much stronger relationshi p with prognosis in female patients, in whom it is the strongest independen t predictor of survival along with age and Binet stage. Interpretation and Conclusions. TD, a quantitative and simple clinical para meter, easily assessed in all patients, offers a reliable tool for evaluati on of tumor cell distribution in B-CLL. It has independent and strong progn ostic power in females, as opposed to males, possibly unmasking important, as yet unrecognized, biological difference in B-CLL patients. (C) 2001, Fer rata Storti Foundation.