Prognosis of Chronic Lymphocytic Leukemia : A Multivariate Survival Analysis of 150 Cases

I N CHRONIC lymphocytic leukemia (CLL), a centam number of prognostic factors have been isolated. Some of them were grouped by Rai et al.’ in a clinical staging system that has been widely acepted and venified.2 However, some attempts to improve this classification have been carried out.79 Recently, an International Workshop on CLL’#{176}has recommended a modified system for CLL staging, which although not considered as a final one, provides advantages in planning treatment and in research because clinical stages are limited to three. In this staging system, patients are classified depending on the pnesence or absence of anemia and/on thrombocytopenia (group C) and the number of “lymphoid” areas enlarged (groups A and B). The International Workshop on CLL has particularly encouraged the investigation of methods to predict within each of the A, B, and C groups subsets of patients who develop a progressive or aggressive clinical course as compared to patients whose clinical course is benign on stable. The analysis of a series of I 50 consecutive patients from our institution supports the new revised proposal for CLL staging. In addition, in the study of this series by means of a multiple regression model developed by Cox ( I 972),’ ‘ lymphocytosis has emerged as a useful parameter to subclassify “low” and “intermediate” CLL stages in both Rai’s and International Workshop on CLL staging systems. This article is a detailed account of this study.