Results of a retrospective analysis showed a significantly elevated risk of bone fractures in a population-based cohort of patients with myeloproliferative neoplasms (MPNs), particularly polycythemia vera (PV), compared with the overall population. These findings were published in Leukemia and Lymphoma.
The Philadelphia chromosome-negative MPNs, characterized by clonal proliferation of 1 or more types of hematopoietic stem cells, include PV, essential thrombocythemia (ET), and primary myelofibrosis (PMF).
In this study, researchers analyzed data from the Swedish Cancer Registry and the Swedish National Board of Health and Welfare to determine the risks of hip and vertebral fracture in a Swedish cohort of adult patients with MPNs compared with the entire adult Swedish population during the period from 1995 to 2015.
Of the 10,572 patients with MPNs identified, 5296 were males and 5456 were females.
At a mean follow-up of 6.34 years, incidences of hip and vertebral fractures were 5% and 1.3%, respectively, in the overall patient cohort with MPN.
Based on the incidence of hip fracture for the entire Swedish population, the observed-to-expected number of hip fractures in the entire cohort of patients with MPN, those with PV, and those with ET were 1.20 (95% CI, 1.10-1.31), 1.37 (95% CI, 1.19-1.58), and 1.02 (95% CI, 0.87–1.19), respectively.
Furthermore, similar comparisons of the observed-to-expected number of vertebral fractures revealed ratios of 1.94 (95% CI, 1.64–2.29) for the overall cohort with MPN, 2.09 (95% CI, 1.56–2.75) for those with PV, and 1.50 (95% CI, 1.06–2.07) for patients with ET.
The study authors note that the “underlying mechanisms [of the increased risk of fractures in MPN] are not known and must be addressed in future studies.”
Johansson P. Kristjansdottir HL, Johansson H, Jakir A, Mellstrom D, Lewerin C. Highly increased risk of fracture in patients with myeloproliferative neoplasm. Leuk Lymphoma. Published online September 10, 2020. doi:10.1080/10428194.2020.1817437