Myelofibrosis (MF)

Myelofibrosis (MF) is a rare, chronic bone marrow cancer in which scar tissue (fibrosis) gradually replaces the normal marrow. Blood cell production is disrupted, and the spleen and liver take over, often becoming enlarged.

About myelofibrosis

What is myelofibrosis?

MF belongs to the myeloproliferative neoplasms. It is driven by acquired gene changes in blood stem cells — most often in JAK2, CALR or MPL — which switch on growth signals and lead to fibrosis and inflammation.

Are there different types of myelofibrosis?

• Primary myelofibrosis — develops on its own
• Secondary (post-PV or post-ET) myelofibrosis — develops from polycythemia vera or essential thrombocythemia
• Pre-fibrotic myelofibrosis — an early form with less scarring

What are the risk factors for myelofibrosis?

• Age over 50
• A previous diagnosis of polycythemia vera or essential thrombocythemia
• Exposure to benzene or high levels of radiation

What are the symptoms of myelofibrosis?

• Fatigue and weakness from anemia
• Fullness or pain under the left ribs and early satiety from an enlarged spleen
• Night sweats, fever, itching and weight loss
• Bone or joint pain
• Easy bruising or bleeding, and a higher risk of blood clots

Diagnosis combines blood tests, a bone marrow biopsy and gene testing, and ends with a risk score that guides treatment.

Blood tests

Blood count and smear often show anemia, abnormal white or platelet counts, and tear-drop shaped red cells with immature cells (a leukoerythroblastic picture). LDH is often raised.

Bone marrow tests

A marrow aspiration is often "dry" because of scarring, so a trephine biopsy is essential. Special stains grade the fibrosis and show the typical abnormal megakaryocytes.

Gene mutation analysis of blood cells

Testing for JAK2, CALR and MPL mutations confirms the diagnosis. Additional high-risk mutations (for example ASXL1) and chromosome tests refine prognosis.

Imaging tests

Ultrasound or MRI measures the size of the spleen and liver and tracks response to treatment.

Risk scores

Scoring systems such as DIPSS-Plus and MIPSS70 estimate the course of the disease and help decide whether a stem cell transplant should be considered.

Treatment is chosen according to risk, symptoms and blood counts. Lower-risk MF without symptoms may only need monitoring.

Targeted therapy

JAK inhibitors — ruxolitinib, fedratinib, pacritinib and momelotinib — shrink the spleen, relieve symptoms such as night sweats and itching, and can improve quality of life and survival. Momelotinib can also help anemia.

Bone marrow / stem cell transplant

An allogeneic stem cell transplant is the only treatment that can cure myelofibrosis. It is considered for fit patients with intermediate-2 or high-risk disease, ideally before the disease becomes advanced.

Treatment of anemia

Blood transfusions, erythropoiesis-stimulating agents, danazol, luspatercept or other medicines may be used.

Chemotherapy

Hydroxyurea may be used to control high blood counts or spleen size in some patients.

Radiation therapy and splenectomy

Low-dose radiation can relieve a painful spleen or areas of blood production outside the marrow. Surgical removal of the spleen is rarely needed.

Holistic care

Nutrition, physiotherapy, symptom management and emotional support are part of every care plan.

Our hematologists and transplant team look after people with myelofibrosis and other myeloproliferative neoplasms.