Chronic lymphocytic leukemia: staging and prognostic factors.

While both the Rai and Binet staging systems continue to provide the most useful tools for assessing prognosis in chronic lymphocytic leukemia (CLL), both fail to identify subsets of patients that may, or may not, benefit from therapy. While numerous factors have been identified that correlate with stage, few have proven to be independent predictors of disease progression, survival, or resistance to chemotherapy. Several factors, including beta2-microglobulin, soluble CD23, and lymphocyte doubling time show particular promise as independent prognostic factors. Their usefulness, however, will remain uncertain until they have been adequately evaluated in prospective, randomized studies. Future studies should focus on the characterization of relevant biologic and immunologic markers in order to direct appropriate treatment for different subsets of patients and to lead to improved outcome in CLL.