Case Studies in Myeloproliferative Neoplasms - Episode 1

Case 1: Hydroxyurea-Resistant Polycythemia Vera (P. Vera)

April 30, 2021
Targeted Oncology

Ruben Mesa, MD: Hello, my name is Ruben Mesa, and I’m the executive director of the Mays Cancer Center at UT Health San Antonio MD Anderson Cancer Center. Thank you for joining us for this Targeted Oncology™ Virtual Tumor Board® focused on myeloproliferative neoplasms [MPNs]. In today’s presentation, my colleagues and I will review 3 clinical cases. We will discuss an individualized approach to treatment for each patient and review key clinical trial data that impacts our decisions. I’m joined today by my good friends and colleagues, including Dr Prithviraj Bose, from The University of Texas MD Anderson Cancer Center [in Houston]. Welcome, Prithviraj.

Prithviraj Bose, MD: Thank you, Ruben.

Ruben Mesa, MD: We’re also joined by Dr Stephen Oh from the Siteman Cancer Center at Washington University in St Louis, Missouri. Welcome, Stephen.

Stephen Oh, MD, PhD: Thanks for having me.

Ruben Mesa, MD: Last but certainly not least, we’re joined by Dr Jamile Shammo from Rush University in Chicago, Illinois. Welcome, Jamile.

Jamile M. Shammo, MD: Thank you, Ruben.

Ruben Mesa, MD: Thank you all for joining us. Prithviraj, why don’t you get us started with the first case?

Prithviraj Bose, MD: Sure, Ruben. Thank you. The case I’m presenting is a case of polycythemia vera [PV]. We’ll walk you through the initial presentation and the disease course of this patient, with a focus on hydroxyurea resistance that eventually develops. This is a 57-year-old man presenting with complaints of headaches, dizziness, excessive sweating, pruritus, and early satiety. The spleen is just palpable 2 cm below the costal margin. There is some plethora. The counts are quite impressive: a hematocrit rate of 66%, a white [blood cell] count of 21 per mm3, platelets of 650 per mm3, and the EPO [erythropoietin] level is extremely low. JAK2 V617F is present, the bone marrow is a classic PV picture: you see the pleomorphic megakaryocytes and panmyelosis. Of course, the patient is diagnosed with polycythemia vera.

Ruben Mesa, MD: Why don’t we jump right into our discussion? You’ve set the stage for PV with this patient. Tell us a little about the footprint of polycythemia vera in the United States. Jamile, what are your thoughts? How big of a problem is this? Roughly how common a disease is this?

Jamile M. Shammo, MD: It’s not very common, and that’s the problem. People often don’t think about polycythemia vera when they are faced with a patient—perhaps a younger individual—who may have symptoms and signs of PV. Sometimes, obtaining a CBC [complete blood count] may not be considered as part of the diagnostic work-up until a lot later in somebody’s history, physical, or even routine exam, which I find to be rather astounding. Because of its rarity, it has certain issues relative to timely diagnosis. It depends on the study that you look at. Incidence could be anywhere from about 1.5 to 2.5 per 100,000 people. I’m curious what other faculty members think. I have seen many patients whose diagnosis may have been overlooked; and not because they didn’t have symptoms. Perhaps their hemoglobin may not have been high enough for them to be considered someone who has polycythemia vera. I’ll stop here and see what others think.

Ruben Mesa, MD: You raised some great points. It was recently Rare Disease Day. I tell my patients with PV that “rare” is in the eyes of the beholder. If you have a disease, it’s not rare. You’ve got it, so it’s clearly a problem for you. But as far as rare diseases go, I tell them that it’s somewhere in the middle. It’s not rare, but not common. This is clearly not the common cold, breast cancer, or prostate cancer, but there are also many incredibly obscure diseases people can have. There are roughly 150,000 patients in the United States. I definitely agree with you that there are probably a lot of more subtle presentations—perhaps not as extreme—because people are iron deficient. Their diagnoses are somewhat masked. Stephen, what are some of the things that should really clue in physicians in internal medicine, family doctors, and ER [emergency department] doctors that somebody might be a PV patient?

Stephen Oh, MD, PhD: As has already been mentioned, patients with polycythemia vera can present in a number of ways. Patients can have relatively minimal symptoms. The tip-off could be that an elevated hemoglobin [level] was detected on a routine CBC. More specifically, there are a couple of things that are pretty characteristic. One that is seemingly unusual is itching. Patients who have polycythemia vera experience aquagenic pruritus in particular, where their itching gets exacerbated by taking a hot shower. That’s something even specialists like us may forget to ask about. Patients have learned over time to stop taking hot showers. That is something that sets off alarm bells for me once you identify that. Looking at the constellation of other symptoms, some of these patients present with a thrombotic event, and that’s the tip-off to initiate the work-up. Some of the symptoms that have been described in this initial case include headaches, dizziness, and weakness. Those things are relatively nonspecific, but when you put them together in conjunction with some of these other features, like early satiety consistent with splenomegaly, those things should certainly point you in the direction of an MPN and possibly polycythemia vera.

This transcript has been edited for clarity.