Prognostic factors and clinical staging in chronic lymphocytic leukemia.

There has been significant progress in the past 10 years in our ability to prospectively predict prognosis in CLL. The clinical staging systems have helped us identify three broad groups of patients with respect to their overall outlook for survival: low risk (stage 0), intermediate risk (stages I and II), and high risk (stages III and IV). It seems reasonable to distinguish those low- and intermediate-risk patients who are likely to have a benign or indolent clinical course if their blood lymphocyte doubling time is longer than 12 months and their bone marrow biopsy pattern of lymphocytic infiltration is nondiffuse. With these guidelines, it will be possible to initiate meaningful and reliable therapeutic trials in CLL in the immediate future.