The link between ≥grade 1 bone marrow reticulin fibrosis in polycythemia vera (PV) and later fibrotic progression was confirmed in a study involving 262 individuals.

Investigators sought to validate certain observations in participants with PV, and looked at other risk factors linked with myelofibrosis-free survival (MFFS). Among the results:

• Nearly half had ≥grade 1 reticulin fibrosis at diagnosis.

• Clinical features were similar in patients with and without bone marrow fibrosis.

• Bone marrow fibrosis did not substantially impact overall, leukemia-free, or thrombosis-free survival.

• Bone marrow fibrosis was linked with 3-fold higher risk of MFFS.

• Other MFFS risk factors included leukocytosis, palpable splenomegaly, and abnormal karyotype.