Myeloproliferative neoplasms are blood cancers that affect myeloid stem cells. Treatment can involve targeted medications or careful monitoring.

Myeloproliferative disorders are a group of cancers involving the uncontrolled replication of cells derived from myeloid stem cells. These cells can become red blood cells, platelets, or some types of white blood cells.

The term “myeloproliferative disorders” was coined in 1951, but the World Health Organization (WHO) now classifies these conditions as myeloproliferative neoplasms. They primarily affect older adults, and it’s estimated that there are 1.7 to 2.4 cases per 100,000 people per year in the United States, based on a 2012 study.

The four most common types of myeloproliferative disorders are:

Read on to learn more about these conditions, including their symptoms, treatment options, and outlook.

Your bone marrow contains blood stem cells that have the potential to become two other types of stem cells called myeloid and lymphoid stem cells.

Myeloid stem cells can become red blood cells, platelets, or some types of white blood cells. Lymphoid stem cells become different types of white blood cells.

Myeloproliferative disorders are a group of cancers that develop in cells derived from myeloid stem cells. There are four main types:

  • Chronic myeloid leukemia (CML): CML is a slow-growing leukemia that starts in immature myeloid cells. About 1 in 526 people in the United States will develop CML in their lifetime.
  • Primary myelofibrosis: In primary myelofibrosis, bone marrow is replaced with a scar-like material that leads to the abnormal production of blood cells. This condition is estimated to develop in 1.5 people per 100,000 per year in the United States.
  • Essential thrombocythemia: If you have essential or primary thrombocythemia, your body produces too many platelets (the cells that help your blood clot). This condition affects about 0.2 to 2.5 people per 100,000 per year.
  • Polycythemia vera: Polycythemia vera causes your body to produce too many red blood cells, which thicken your blood. It’s estimated to affect 0.7 to 2.6 people per 100,000 per year.

Rarer types of myeloproliferative disorders include:

  • Chronic neutrophilic leukemia (CNL): CNL is an extremely rare condition involving the overproduction of white blood cells called neutrophils.
  • Chronic eosinophilic leukemia (CEL): CEL is a rare leukemia that causes your body to overproduce white blood cells called eosinophils, which release chemicals in response to infections and allergies. CEL usually progresses slowly. Less commonly, it changes into an aggressive type of leukemia called acute myeloid leukemia (AML).

Symptoms vary depending on what type of myeloproliferative disorder you have. It’s common not to have any symptoms in the early stages of these diseases.

Here’s a look at some potential signs and symptoms of the most common myeloproliferative disorders:

CML

Polycythemia vera

Essential thrombocythemia

  • headache
  • dizziness
  • vision changes
  • a burning or prickling feeling in your limbs
  • fatigue
  • easy bruising
  • stroke-like symptoms
  • enlarged spleen

Primary myelofibrosis

Myeloproliferative disorders are caused by the overproduction of blood cells, but the exact reason they occur is not known. They tend to develop in older adults and are more common in males overall. A combination of environmental and inherited genetic factors likely play a role.

People with a Janus kinase 2 (JAK2) mutation have a higher risk of developing myeloproliferative disorders. Exposure to ionizing radiation and chemicals such as benzene may also increase the risk.

The first step toward getting a diagnosis of a myeloproliferative disorder is to contact a healthcare professional and schedule an appointment. They will perform a physical exam and evaluate your medical and family history.

If they suspect a blood disorder, they’ll likely order blood tests. Healthcare professionals may use many blood tests to help diagnose myeloproliferative disorders, such as:

A definitive diagnosis is usually made with a bone aspiration and biopsy. During this procedure, a doctor uses a long, thin needle to take a sample of your bone marrow for lab analysis.

Allogeneic stem cell transplantation is the only potential cure for myeloproliferative disorders. This procedure involves receiving donor bone marrow stem cells after receiving a high dose of chemotherapy. It’s usually an option only for people who are in good overall health.

CML

The main treatments for CML are drugs called tyrosine kinase inhibitors (TKIs). These drugs target a protein that helps CML cells grow. TKIs that may be used to treat CML include:

A healthcare professional may recommend chemotherapy, with or without an allogeneic stem cell transplant, if you cannot take these medications or if you have advanced CML.

Polycythemia vera

Polycythemia vera treatment focuses on reducing the thrombosis risk and providing symptom relief.

People who are under 60 years old and do not have a history of blood clots are considered to have a low risk of developing blood clots. Treating polycythemia vera in people at low risk can involve:

  • watchful waiting
  • low dose aspirin
  • management of cardiovascular risk factors
  • phlebotomy (a procedure in which extra red blood cells are removed with a needle)

People who are at high risk may take medications to reduce their blood cell count.

Essential thrombocythemia

Essential thrombocythemia is usually treated with watchful waiting or low doses of aspirin. People at high risk may also receive medications to lower their blood cell count.

Primary myelofibrosis

People who are not experiencing symptoms of primary myelofibrosis generally do not need treatment. For people who are low risk and are experiencing symptoms, healthcare professionals may prescribe the following medications:

People at intermediate or high risk might also receive the following medications:

  • pacritinib (Vonjo)
  • ruxolitinib (Jakafi)
  • fedratinib (Inrebic)
  • momelotinib (Ojjaara)

Additionally, people at intermediate or high risk may be treated with an allogeneic stem cell transplant. Some might also receive treatment for anemia.

Your outlook depends on factors such as:

  • the type of myeloproliferative disorder you have
  • how far the condition has progressed
  • your overall health
  • your age

The outlook for CML has improved in recent years with the development of new medications. As of 2024, the 5-year relative survival rate for CML is 70%, according to the National Cancer Institute. This means that someone with CML is 70% as likely to survive for 5 years after diagnosis as someone without CML.

Earlier studies cited in a 2018 review have reported the following findings:

  • Among a sample of 267 people with primary myelofibrosis, half lived for 5.9 years.
  • Half of people with polycythemia vera lived at least 13.5 years.
  • Half of people with essential thrombocythemia lived 19.8 years.

Myeloproliferative neoplasms are a group of cancers that cause the overproduction of cells that can become red blood cells, platelets, or some types of white blood cells.

The symptoms, treatment options, and outlook depend on which specific condition you have.

If you receive a diagnosis of a myeloproliferative neoplasm, your doctor can recommend the best treatment option. If your condition is in the early stages, they may recommend simply waiting to see how it develops.