Myeloproliferative Neoplasm

Alternative names: MPN, Myeloproliferative Neoplasms (MPNs), Chronic Myeloproliferative Disorder; previously known as Myeloproliferative Disease (MPD)

Myeloproliferative disorders are a group of slow-growing blood cancers in which large numbers of abnormal red blood cells, white blood cells, or platelets grow in the bone marrow and circulate in the blood.

The increased numbers of blood cells may not cause any symptoms by themselves, but a number of resulting medical problems may cause symptoms.

Causes and Development

All myeloproliferative disorders are caused by overproduction of one or more types of cells.  No one knows what triggers this overproduction, but theories include genetics and environmental causes such as an overexposure to radiation, electrical wiring, or chemicals.

Signs and Symptoms

Many patients show no symptoms but one symptom shared by all myeloproliferative disorders, with the exception of essential thrombocytosis, is an enlarged spleen.  An enlarged spleen can cause abdominal pain and a feeling of fullness.  Other signs and symptoms depend on the underlying condition and include:

• Becoming tired easily; fatigue; general malaise
• Trouble breathing
• Pale skin (pallor)
• Petechiae and/or ecchymoses – purple spots or patches on the skin
• Bruising
• Intense itching after bathing in warm water
• Burning or throbbing and burning pain in the skin, often with redness or darkened, blotchy areas
• Swelling of the hands and feet
• Anorexia; unusual weight loss
• Loss of appetite
• Abdominal discomfort
• Stomach aches
• A feeling of abdominal fullness caused by enlargement of the spleen (Most common in Chronic Myelogenous Leukemia and Agnogenic Myeloid Metaplasia)
• Fever
• Night sweats
• Easy bruising and bleeding, and/or symptoms of thrombosis
• Nosebleeds
• Headache
• Vision problems
• Bleeding gums
• Gastrointestinal bleeding
• Blood in the urine
• High blood pressure
• Blockage of blood vessels, potentially leading to heart disease, stroke, or gangrene (tissue death) of the arms and legs
• Painful swollen joints, caused by gouty arthritis, which is in turn caused by hyperuricemia
• Bone pain
• Priapism
• Tinnitus
• Stupor due to leukostasis
• Left upper quadrant and left shoulder pain (due to spleen tissue death and inflammation of the surface of the spleen)
• Enlarged spleen and/or liver
• Occasionally, a syndrome of fever with painful, maculopapular, violet-colored sores across the body; this is known as acute febrile neutrophilic dermatosis, or Sweet syndrome
• Infection

Diagnosis and Tests

Bone marrow aspiration and biopsy with cytogenetic studies are required in most, but not all, patients.  Bone marrow histology shows hypercellularity in most of these disorders.

Blood tests help find abnormal types or numbers of red or white blood cells.  They can also detect anemia and leukemia.

Useful laboratory tests include:

• Complete blood count (CBC) and differential count with microscopic examination of the peripheral smear
• Leukocyte alkaline phosphatase (LAP) score, to differentiate chronic myelogenous leukemia from other causes of leukocytosis
• Polymerase chain reaction (PCR) assay or fluorescent in-situ hybridization (FISH) run on peripheral blood, to help differentiate chronic myelogenous leukemia from other myeloproliferative diseases
• PCR assay run on bone marrow in suspected cases of polycythemia vera, essential thrombocythemia, and myelofibrosis
• Red blood cell mass study
• Serum uric acid level

Treatment and Prevention

As at the time of writing, experimental drug therapies do exist but there is no cure for any of the MPDs.  The goal of treatment depends on the specific diagnosis, for example prevention of thrombo-hemorrhagic complications or reducing the severity of anemia, splenomegaly, and other symptoms.

Low-dose aspirin is effective in Polycythemia Vera and Essential Thrombocythemia.  Tyrosine kinase inhibitors have improved the prognosis of Chronic Myelogenous Leukemia patients.

A person's diagnosis and symptoms will determine the specific types of medication prescribed.  Myeloproliferative disorders need conventional medical treatment but a treatment plan may also include a range of complementary and alternative therapies.  Following a healthy diet and getting regular exercise may help to keep your body strong while coping with a myeloproliferative disorder.

• Eat antioxidant-rich foods, including fruits (such as blueberries, cherries, and tomatoes), and vegetables (such as squash and bell peppers)
• Avoid refined foods such as white breads, pastas, and especially sugar
• Eat fewer red meats and more lean meats, cold-water fish, tofu (soy, if no allergy), or beans for protein
• Use healthy oils, such as olive oil or vegetable oil
• Reduce or eliminate trans-fatty acids, found in store-bought cookies, crackers, cakes, French fries, onion rings, donuts, processed foods, and margarine
• Avoid caffeine, alcohol, and tobacco
• Drink 6-8 glasses of water daily
• Exercise at least 30 minutes daily, 5 days a week

The following supplements may help:

• A daily multivitamin containing the antioxidant vitamins A, C, E, the B-complex vitamins, and trace minerals such as magnesium, calcium, zinc, and selenium
• Omega-3 fatty acids such as fish oil, 1 – 2 capsules or 1 – 3 tablespoonfuls oil, 1 – 3 times daily, to help decrease inflammation and help with immunity
• A probiotic supplement containing Lactobacillus acidophilus, 5-10 billion CFUs (colony forming units) a day, when needed for maintenance of gastrointestinal and immune health.

These herbs may also produce benefits:

• Green tea (Camellia sinensis) standardized extract, 250-500mg daily, for inflammation, and for antioxidant and immune effects.
• Indirubin (Indigofera tinctoria) – Case reports show positive results in treating CML long-term with indirubin.  However, no scientific studies have been done on using indirubin for CML.
• Olive leaf (Olea europaea) – for anticancer and immune effects.
• Turmeric (Curcuma longa) – for pain and inflammation.

Prognosis; Complications

The survival rate for myeloproliferative disorders varies, depending on both the type of disorder and the kind of symptoms each person experiences.

Though myeloproliferative disorders are serious and pose certain health risks, people with these conditions often live for many years after diagnosis.  The prognosis largely depends on the type of underlying disorder.  Myeloproliferative disorders usually get worse over time as the number of extra cells build up in the blood and/or bone marrow.

The build up of extra cells may cause thrombotic and hemorrhagic events, anemia, infection, fatigue, or other signs and symptoms.  Myeloproliferative neoplasms are slow acting, and don't always cause life-threatening symptoms.  The complications, however, may be serious and include:

• Enlargement of the spleen and liver
• Gout
• Anemia
• Bleeding
• Kidney or liver failure
• Heart attacks or stroke
• Infection
• Transformation of CML into acute myeloid leukemia (AML), a more dangerous condition, either as a result of the underlying disorder, or as a consequence of the treatment.