Myeloproliferative Neoplasms - Episode 10
Andrew Kuykendall, MD: When we look at the NCCN [National Comprehensive Cancer Network] guidelines for polycythemia vera, we start by risk stratifying patients as either low risk or high risk. This is pretty rudimentary. Lower-risk patients are considered those who are younger than 60 years of age and have no prior history of thrombosis. These patients are monitored for any new thrombotic events or bleeding. We make sure to focus on other cardiovascular risk factors and make sure that those are managed appropriately. We recommend a low-dose aspirin regimen as well as phlebotomies to maintain hematocrit levels less than 45%.
Typically, we’ll keep an eye on these patients every 3 to 6 months to ensure that no other events are happening and that symptoms are controlled. In patients who remain asymptomatic and are otherwise low risk, we continue with just aspirin and phlebotomies. In patients who develop some other disease-related issues, certainly a cytoreductive therapy can be considered, and there’s a list of those here from the NCCN guidelines.
Obviously, new thrombosis or disease-related bleeding would shift the patient over into the high-risk category. But also things like frequent need for phlebotomy or poor tolerance of phlebotomy, an enlarged spleen, uncontrolled blood counts (other than hematocrit, such as thrombocytosis or leukocytosis and disease-related symptoms) could all be considerations or factors that would indicate a good time to start someone on some cytoreductive therapy. And then certainly if the disease progresses over to myelofibrosis or acute leukemia, that pushes a patient down a different pathway.
For high-risk patients, which is either someone age 60 or older or has any prior history of a thrombotic event, the management is very similar in the sense that we’re still monitoring for new thrombotic events, managing risk factors, aspirin at a low dose, phlebotomy. But, now we consider the addition of cytoreductive therapy, and by this, we often mean either hydroxyurea or an interferon-based therapy. Keeping an eye on patients every few months, assessing for response and management of disease-related factors, and if everything is going well, we continue on the same treatment.
If there’s any kind of inadequate response or loss of response, which is a few items here listed such as intolerance to the hydroxyurea or interferon, a new event such as a thrombotic event or bleeding, any continued need for phlebotomy or poor tolerance, and then once again splenomegaly, thrombocytosis, leukocytosis, or disease-related symptoms, that might push someone to change therapy or alter therapy in some fashion. The options for altering therapy—once again, you have hydroxyurea and interferon, using an agent we haven’t used before, but now you have the addition of ruxolitinib, which has been studied in this setting and clinical trials are always an option as well. And certainly if the disease progresses, we go down a different pathway.
Transcript edited for clarity.