Myeloproliferative Neoplasms

Myeloproliferative Neoplasms (MPNs):
The Basics

Myeloproliferative Neoplasms (MPNs) are types of blood cancer that begin with an abnormal mutation in a stem cell in the bone marrow. The diseases occur when the bone marrow makes too many red blood cells, white blood cells, or platelets. There are six types of MPNs:

• Chronic myelogenous leukemia
• Polycythemia vera
• Primary myelofibrosis (also called chronic idiopathic myelofibrosis)
• Essential thrombocythemia
• Chronic neutrophilic leukemia
• Chronic eosinophilic leukemia

How treatment is approached will depend on which type of MPN a person has.

Dr. Adrienne Phillips, a hematologist/medical oncologist at Weill-Cornell/New York Presbyterian Hospital, explains the different types of MPNs.

Symptoms & Diagnosis

Symptoms that indicate an MPN can vary depending on when a patient is first diagnosed, Dr. Adrienne Phillips, a hematologist and medical oncologist at Weill-Cornell/New York Presbyterian Hospital, told SurvivorNet.

“Myeloproliferative Neoplasms are kind of what it sounds like … your bone marrow is proliferating; it’s making too many blood cells”
– Dr. Adrienne Phillips

“Symptoms of MPNs really depend on if you’re diagnosed early in the course of the MPN or later in the course of the MPN,” Dr. Phillips explained. “If it’s an early diagnosis, maybe it’s just picked up on routine blood work where your doctor notices your hemoglobins higher than it should be. Your platelets are higher than it should be.”

In instances where a patient is asymptomatic, the workup would be what ultimately leads to the diagnosis. Patients whose disease has progressed a bit more may develop symptoms such as:

• Swelling in the belly due to an enlarged spleen or liver
• Fever
• Night sweats
• Itchiness in the skin
• Weight loss

To determine what type of disease a patient has, doctors will perform tests such as a physical exam and health history survey, a complete blood count (CBC) with differential (a sample that measures blood counts), a peripheral blood smear (where doctors observe the shape, counts, and other aspects of blood), blood chemistry studies, bone marrow aspiration and biopsy (where doctors observe a small piece of bone marrow, blood, and bone), a cytogenetic analysis (where chromosomes in bone marrow and blood samples are examined), and a gene mutation test.

Treatment

Treatment will depend on which type of MPN a person has, as well as several other factors.

“Myeloproliferative Neoplasms (MPNs) is kind of the overarching title of these diseases and the therapy really depends on what the condition specifically is,” Dr. Phillips explained. In some instances, patients may be able to take a “watch and wait” approach to treatment, but in others, treatment will be necessary as soon as possible.

Chronic myelogenous leukemia (CML)

“If you have chronic myelogenous leukemia (CML), which is a type of myeloproliferative neoplasms, you’re going to be on a therapy that targets the Philadelphia chromosome, which is the genetic mutation of CML. You’ll be on the pill forms of therapy probably for years,” Dr. Phillips explained.

Polycythemia vera

“Patients with polycythemia vera might need to have what we call phlebotomy … so, they might need to have blood draws every month to make sure that their hemoglobin isn’t too high to prevent them from getting strokes. They might be on a medication called hydroxyurea, which lowers overall blood counts,” Dr. Phillips explained.

Dr. Ghaith Abu-Zeinah, a hematologist/oncologist at Weill Cornell Medicine, explains how PV is treated.

Essential thrombocythemia

Dr. Phillips noted that patients with essential thromocythemia may also need to be on therapy to lower blood counts. However, if a patient is younger (typically under 60) and has an acceptable blood count and no symptoms, a watchful waiting approach may be taken.

“On the spectrum of the MPNs [ET] is probably
the least aggressive of all subtypes”
– Dr. Ghaith Abu-Zeinah

Primary myelofibrosis

Patients with myelfiboris, if they are displaying signs of anemia (like fatigue or dizziness), may be treated with a steroid or erythropoietic growth factors. Patients experiencing a lot of symptoms may be given a targeted therapy, like ruxolitinib, or a handful of other treatments.

Dr. James Mangan, hematologist/medical oncologist at the University of California San Diego, explains new treatment options for myelofibrosis-related anemia.

Chronic neutrophilic leukemia and chronic eosinophilic leukemia

Treatment for chronic neutrophilic leukemia (CNL) and chronic eosinophilic leukemia (CEL) may involve a bone marrow transplant, immunotherapy, or enrollment in a clinical trial. CNL may also be treated with chemotherapy.