Underutilization of cytoreductive treatments may be a significant concern for older patients with polycythemia vera (PV), according to a study published in Blood Advances.
Researchers used the linked SEER-Medicare database to conduct a retrospective cohort study of 820 older adults (median age 77 years) diagnosed with PV between 2007 and 2013. Overall, 336 patients (41.1%) were treated with both phlebotomy and hydroxyurea, 189 patients (23.0%) were treated with phlebotomy only, 161 patients (19.6%) were treated with hydroxyurea alone, and 134 patients (16.3%) received neither phlebotomy nor hydroxyurea. Outcomes were overall survival (OS) and occurrence of a thrombotic event after diagnosis of PV.
The researchers found that 37.2% of patients died after a median follow up of 2.83 years. Phlebotomy users had a median survival of 6.29 years, compared with 4.50 years (P <.01) for phlebotomy nonusers. Hydroxyurea users had a median survival of 6.02 years, compared with 5.25 (P <.01) years for hydroxyurea nonusers. Treatment with phlebotomy, increasing phlebotomy intensity, and a higher proportion of days covered by hydroxyurea were all associated with both lower mortality (P <.01) and a lower risk of thrombotic events (P <.01).
Though the findings showed improved OS and decreased risk of thrombosis in older patients with PV treated with phlebotomy and hydroxyurea, it also demonstrated that both treatment modalities were underused in this population. Only 64.0% of patients underwent therapeutic phlebotomy, and only 60.6% patients received hydroxyurea. The researchers concluded that older patients may be undertreated according to current guidelines, and improving awareness of the guidelines may lead to better outcomes.
1. Podoltsev NA, Zhu M, Zeidan AM, et al. The impact of phlebotomy and hydroxyurea on survival and risk of thrombosis among older patients with polycythemia vera [published online October 17, 2018]. Blood Advances. doi: 10.1182/bloodadvances.2018021436