A gender-based score system predicts the clinical outcome of patients with early B-cell chronic lymphocytic leukemia

Abstract

To facilitate the development of a prognostic model for early B-cell chronic lymphocytic leukemia (CLL), the Gruppo Italiano Malattie EMatologiche Maligne dell'Adulto (GIMEMA) proposes its multi-institutional effort as a working model. In total, 1138 newly diagnosed Binet stage A patients managed over the last 10 years outside the setting of clinical trials according to a "wait and see" policy form the basis of the present study aimed at investigating prognostic variables affecting disease progression, a surrogate endpoint for overall survival. A 3-stage risk system, simply obtained by summing the variables that proved significant in the multivariate analysis (i.e. short lymphocyte doubling time, advanced Rai substage, high peripheral blood lymphocytosis), is proposed. Clear-cut differences in the 10 year progression-free survival (PFS) were observed among patients scoring 0 (low risk), 1 (intermediate risk), 2-3 (high risk): 67.8, 41.0 and 24.8%, respectively (P<0.0001). The results of the Medical Research Council (MRC) suggesting a better clinical outcome for females prompted us to verify such a gender-related difference within our prognostic categories. Because changes in PFS only reflected gender for patients scoring 0 (P=0.04), the following prognostic subgroups are proposed: (1) females scoring 0; (2) males scoring 0; (3) patients scoring 1-3 whatever gender (10 year PFS: 76.2, 61.4 and 37.8%; P<0.00001). Our long-term database provides an adequate patient sample to generate a generalized risk stratification model based on clinical data. The indolent clinical outcome of women with early CLL is also supported by the higher frequency of the immunoglobulin heavy-chain variable (IgVH) mutational status and lower proportion of 17p and 11q deletions found in such a patient subset in the MRC CLL4 trial.