Imatinib mesylate therapy reduces bone marrow fibrosis in patients with chronic myelogenous leukemia.

Background: Reticulin-stained bone marrow fibrosis is associated with a poor prognosis in patients with chronic myelogenous leukemia (CML). Resolution of fibrosis with therapy may improve patient outcome.
Methods: The effect of imatinib therapy on bone marrow fibrosis was evaluated in 40 patients with chronic-phase CML who were treated after interferon-alpha failure.
Results: Thirty-one patients (78%) had severe (Grade 3 or 4) reticulin fibrosis prior to therapy. After imatinib therapy was administered for 3 to > 24 months, fibrosis was reduced by at least 2 grades in 19 of the 31 patients (61%) and by at least 1 grade in 34 patients (85%). There was no correlation noted between reduction of fibrosis and cytogenetic response. However, a reduction in fibrosis was found to correlate with a reduction in bone marrow megakaryocytosis (P = 0.002).
Conclusions: Treatment with imatinib mesylate appears to reduce CML-associated bone marrow fibrosis in most patients who are treated during the chronic phase of disease. This effect may be independent of the degree of suppression of Philadelphia chromosome-positive cells, and may improve prognosis in patients with CML.
(Copyright 2004 American Cancer Society.)