Prognostic value of bone marrow histology in chronic lymphocytic leukemia: a study of 335 untreated cases of a single institution

Background and Methods. A significant correlation between bone marrow (BM) histology, survival and disease progression (DP) probability has been observed by several authors in chronic lymphocytic leukemia (CLL). The prognostic value of BM histologic patterns on survival and disease progression probability was investigated in 335 B-CLL patients. Results. Actuarial survival probability estimated by univariate analysis proved to be significantly influenced by stage (p<0.0001), BM histology (p=0.01), and by the following parameters: anemia (p=0.0005), splenomegaly (p<0.001), CLL-related symptoms (p<0.01), thrombocytopenia (p<0.01), number of involved nodal areas (p=0.01) and peripheral lymphocyte count over 30x 10(9)/L (p<0.05). In this series we did not detect a discriminating prognostic effect for BM histology within the individual stages. Cox multivariate regression analysis failed to demonstrate a significant value for BM histology, while stage and anemia emerged as the best prognostic variables. Actuarial DP free probability in 294 untreated patients with A and B stages was significantly related to stage (p<0.00001) and to BM pattern (p=0.01). Conclusions. Despite the clear correlation between the D pattern of BM involvement and advanced and early progressive disease, we were unable to demonstrate an independent prognostic value for BM histology. These findings suggest that stage emerged as the best predictive factor of survival probability in our B-CLL patients.