Bone Marrow Fibrosis of Adult Patients in Mexico

The role of bone marrow (BM) fibrosis on outcomes of children with acute lymphoblastic leukemia (ALL) has been described with inconsistent results, while in adults there is no information regarding its significance. Considering the poor outcomes of adult patients with ALL, the aim of this study was to describe the prognostic impact of BM fibrosis in this group of patients. We included 88 biopsies of 44 adult patients. Masson trichrome stain and grading of fibrosis by Bauermeister scale and volume of reticulin fibers was performed. Patients were classified in 3 groups: without fibrosis at diagnosis (Group 1), with fibrosis and reduction of volume of reticulin fibers <50% (2) or ≥50% (3). At diagnosis 66% (n=29) had significant fibrosis with a median volume of reticulin fibers of 15.3% at diagnosis and 9.5% post-induction. Fibrosis at diagnosis had no impact over the outcomes, however, reduction of ≥50% of the volume of reticulin fibers after induction was associated with less induction failure (10% vs. 46%, p=.018), longer relapse free survival (12.1 months vs. 10.5 months, p=.037) and longer overall survival (28.3 months vs. 13.1 months, p=.028). To our knowledge, this is the first study to demonstrate that significant bone marrow fibrosis at diagnosis and its subsequent reduction is related to a better clinical outcome in adult patients with ALL.