Bone marrow fibrosis in chronic myelomonocytic leukemia is associated with increased megakaryopoiesis, splenomegaly and with a shorter median time to disease progression

// Kseniya Petrova-Drus 1 , April Chiu 2 , Elizabeth Margolskee 3 , Sharon Barouk-Fox 3 , Julia Geyer 3 , Ahmet Dogan 1 and Attilio Orazi 3 1 Department of Pathology, Memorial Sloan Kettering Cancer Center, New York, NY, USA 2 Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, USA 3 Department of Pathology and Laboratory Medicine, New York Presbyterian Hospital–Weill Cornell Medicine, New York, NY, USA Correspondence to: Kseniya Petrova-Drus, email: petrovak@mskcc.org Keywords: chronic myelomonocytic leukemia, bone marrow fibrosis, myeloid neoplasms Received: August 24, 2017 Accepted: September 29, 2017 Published: October 17, 2017 ABSTRACT Bone marrow (BM) fibrosis is an adverse prognostic marker in several myeloid neoplasms, particularly in myelodysplastic syndrome (MDS) with fibrosis; however, its significance in chronic myelomonoctyic leukemia (CMML) has not been evaluated. We performed a retrospective analysis to investigate the prognostic and clinicopathological features of CMML with and without BM fibrosis. The study included specimens from a total of 83 untreated CMML patients from 2 large institutions. Patients with any amount of BM fibrosis (MF-1 or higher; MF1+) had significantly shorter progression-free survival (MF1+, 28.3 months vs MF0, not reached; p = 0.001, log rank test), splenomegaly ( p = 0.016), and increased BM megakaryocytes ( p = 0.04) compared to patients without BM fibrosis (MF-0). No association was observed between fibrosis and peripheral blood parameters, presence of JAK2 V617F mutation, BM blasts, or overall survival. Our study demonstrates the importance of assessing BM fibrosis in CMML. Similar to MDS, the presence of BM fibrosis may identify a distinct subgroup of CMML patients (CMML-F) with a more aggressive clinical course.