Yale Study Shows Treatment Underutilization and Supports NCCN Guideline Recommendations for Patients with PV
A recent study by Nikolai A. Podoltsev, MD, PhD, Assistant Professor of Medicine, Yale School of Medicine, New Haven, Connecticut, and colleagues has shown that the treatment recommended by the National Comprehensive Cancer Network (NCCN) and European Leukemia Net (ELN) guidelines for polycythemia vera (PV)—therapeutic phlebotomy, plus cytoreductive therapy in high-risk patients—is underused among patients with this disease, despite having been shown to improve outcomes.
Oncology Learning Network spoke with Dr Podoltsev about the use of phlebotomy and cytoreductive therapy in older patients with PV, and possible reasons for why this treatment is being underused.
Can you briefly describe the role of phlebotomy and cytoreductive therapy in the treatment guidelines for patients with PV?
Both the NCCN and ELN guidelines recommend therapeutic phlebotomies for all patients with PV to maintain a hematocrit goal of <45%, which helps reduce cardiovascular mortality and major thrombotic events. Cytoreductive therapy is reserved for patients with PV who have high thrombotic risk, including those aged >60 years or with a history of thrombotic events, and helps to further reduce the risk thrombosis.
What lead you to evaluate the current use of phlebotomy and hydroxyurea among older patients with PV?
There is limited real-world data in regard to outcomes among older patients with PV who are being treated according to current guidelines. The recommendation to use hydroxyurea for high-risk patients with PV is based mostly on observational studies and its use in PV remains the subject of professional debate. SEER–Medicare data provided us with a unique opportunity to study the use and outcomes of these treatments in a large cohort of older patients with high-risk disease.
Can you briefly describe the results of your study?
We observed improved overall survival and decreased risk for thrombosis in older patients with PV treated with phlebotomy and hydroxyurea. Among 820 patients, those treated with phlebotomy had a 35% reduction in death and a 48% reduction in the risk for thrombosis. Every 10% increase in the proportion of days patients used the hydroxyurea led to an 8% lower risk for death and thrombosis.
However, both treatment modalities were underused, as only 64% of patients underwent therapeutic phlebotomy and only 60% received hydroxyurea. These findings suggest that patients in our study cohort were undertreated according to ELN and NCCN guidelines.
In your opinion, why is this treatment approach underused, despite being recommended by the NCCN and ELN?
Treatments may be underused because of physicians’ lack of familiarity with guidelines and underappreciation of the importance of guideline-based recommendations. There may also be a concern among providers in regard to the potential for treatment-related side effects among older patients with PV.
We hope that the introduction of the NCCN clinical practice guidelines for myeloproliferative neoplasms (MPNs), which were first published in 2017, will help bridge the gap between evidence-based recommendations and real-world treatment of patients with PV.
Do you intend to expand upon these findings with further research? If so, what will your next steps be?
We conducted a separate study looking at hydroxyurea use among older patients with essential thrombocytopenia, another MPN; results from this study will be published shortly in the Journal of the National Comprehensive Cancer Network.
Another guideline-based recommendation for patient with MPNs is to address modifiable cardiovascular risk factors. Preliminary results of our study looking at the use of statins in this group of patients, as well as their outcomes, will be presented at the 2018 American Society of Hematology Annual Meeting and Exposition.