What are MPNs?

Myeloproliferative neoplasms (MPNs) are rare types of blood cancers. The first part of the first word – myelo – refers to bone marrow. Almost all bones have a soft center, called marrow, where most blood cells are formed. The second part of the first word – proliferative – refers to the rapid growth of cells. A neoplasm is an abnormal growth of cells.

There are three classic types. The progression of these cancers is typically slow, and diagnosing them can be difficult. Despite living long lives, many people suffer from distressing symptoms.

In MPNs, the bone marrow typically overproduces one of the mature blood elements as part of chronic, progressive cancers of the blood. There are also common characteristics such as blood clotting/bleeding, organ enlargement, bone marrow scarring (fibrosis), and the ability to transform into another MPN or chronic cancer. The majority of MPN patients are in their sixth decade of life or later, although they can strike at any age.

MPNs are usually characterised by abnormal growth of white blood cells, red blood cells, and platelets, which have been linked to gene mutations (errors), which are acquired over time. Currently, researchers are studying how a person’s genetics at birth may affect their susceptibility to MPNs in the future.

Even though stem cell transplants are the only potential cure today, many patients with MPN can enjoy quality of life and longevity without needing a transplant.

As a result of the identification of the mutated JAK2 gene in 2005 and of the mutated CALR gene in 2013, significant advances have been made in the diagnosis, understanding, and treatment of MPNs.


MPN Horizons 6-8 September 2024

What are the symptoms of MPNs?

MPNs are chronic cancers. Chronic cancers worsen slowly. Treatment may not be needed right away or ever, but these cancers are not typically cured. Early symptoms may not occur. As symptoms start, they can be mild to severe. These may symptoms include:

  • tiredness (fatigue)
  • bruising or unusual bleeding
  • getting more infections than usual
  • problems with your eyes – such as blurred vision
  • ringing in your ears
  • night sweats
  • itchy skin (pruritis)
  • weight loss
  • frequent headaches

Picture of bone narrow

Types of MPNs

There are three types of “classic” MPNs: essential thrombocythemia (ET), polycythemia vera (PV), and myelofibrosis (MF). They all share some symptoms, such as headaches, fatigue, bone pain, tingling, and itching.

  • Essential thrombocythemia (ET)
    Typically, ET is characterized by an elevated level of platelets in the blood. In most cases, women over 50 are affected, and blood clotting and bleeding are common complications. MF progression is more likely to occur in ET patients.
  • Polycythemia vera (PV)
    In most cases, PV is diagnosed in men over 60 who have an elevated level of red blood cells. As well as elevated white blood cell and platelet counts, PV patients often have an enlarged spleen. Patients with PV are more likely to develop MF later in life.
  • Myelofibrosis (MF) 
    In MF, bone marrow function is affected by scarring and occurs most commonly in men and women over the age of 60. It is common for patients to have associated symptoms and an enlarged spleen. Patients with primary MF may have no prior history of an MPN or it may develop as a progression of PV or ET.

For a bigger and more detailed understanding please download and read the NCCN guideline HERE.

References: MPN research Foundation and NCCN Guidelines.