B-chronic lymphocytic leukemia. Disease progression in 150 untreated stage A and B patients as predicted by bone marrow pattern.

Previous studies have shown that the pattern of bone marrow (bm) involvement in B-CLL patients is the single most important prognostic factor. In the present study we analyse the disease progression observed in 45 out of 150 untreated stages A and B, B-CLL patients in relation to their pattern of bm involvement. The mean treatment free period was 45 months (10-130). The distribution of bm patterns and disease progression in our series was as follows: in stage A, Bm patterns diffuse in 24 cases (21.8%); in stage B: in 21 cases (52.5%). Disease progression from stage A to stage B or C and from stage B to stage C was found 50% of the A and B-diffuse patients as compared to 10% of the A and B-nondiffuse. The mean period during which this progression occurred was 18 months for the stages A and B with a diffuse pattern and 59 months for the stages A and B with a nondiffuse pattern. No differences could be observed in the nondiffuse group when our patients were analysed on the basis of nodular, interstitial and mixed pattern of bm involvement. All progressed patients required therapy. These findings support our previous observations, and present further evidence that in B-CLL patients with a diffuse pattern of bm disease at diagnosis, treatment should be initiated independently of their clinical stage.