What Are Myeloproliferative Neoplasms?
Myeloproliferative Neoplasms (MPNs), also known as Myeloproliferative Disorders, are a group of diseases where the bone marrow produces too many blood cells, leading to scarring of the bone marrow (fibrosis).
Are Myeloproliferative Neoplasms a cancer?
MPNs are considered a type of blood cancer that begins with an abnormal mutation (change) in a stem cell, which is in the bone marrow. The mutated cell causes an overproduction of any of the platelets, white, and red blood cells.
What Are the Four Myeloproliferative Neoplasms?
The 4 most common MPNs are:
- Polycythemia vera (PV): Overproduces red blood cells in bone marrow. Cells in the blood build up to cause an enlarged spleen and itching throughout the body.
- Essential thrombocythemia (ET): Blood platelets are produced in excess and are the only type of cell effected. Blood flow is slowed down by platelets causing the blood to be sticky.
- Primary myelofibrosis (PMF): Abnormal blood cells and fibers build up in the bone marrow and cause scarring (fibrosis).
- Chronic myelogenous leukemia (CML): A genetic change takes place in the cells that produce red blood cells, white blood cells, and platelets
The remaining 2 MPNs are rare, which include:
- Chronic neutrophilic leukemia: Bone marrow cells that produce blood cells develop and function abnormally
- Chronic eosinophilic leukemia/Hypereosinophilic Syndrome (HES): Too many eosinophils, a type of white blood cell, are found in the bone marrow and blood.
Are Myeloproliferative Neoplasms Leukemia?
The MPNS considered leukemia are HES, CML, PMF, and CNL. In addition, the remaining MPNs can develop into leukemia in some cases if left untreated.
Myeloproliferative Neoplasm Diagnosis
Some cases of MPNs are discovered during routine blood tests
Tests that examine the blood and bone marrow are used to diagnose MPNs, which include:
- Physical exam and health history: Doctors will perform an exam of the body to check general signs of health, including checking for signs of disease, such as lumps or anything else abnormal. They will also collect a history of the patient’s health, past illnesses, and previous treatments.
- Complete blood count (CBC) test: A procedure in which a sample of blood is drawn, and the following is checked:
- Number of red blood cells and platelets
- Number and type of white blood cells
- How much of the blood sample is made up of red blood cells?
- Amount of hemoglobin (protein that carries oxygen) in the red blood cells
Peripheral blood smear: A procedure in which a sample of blood is examined for the number of white blood cells, platelets, blast cells, and the shape of the red blood cells.
Blood chemistry studies: A blood sample is taken to measure the amounts of substances released into the blood by organs and tissues in the body. An unusual amount of a substance can be a sign of diseases such as MPNs.
Bone marrow aspiration and biopsy: The removal of bone marrow, blood, and a small piece of bone with a hollow needle in the pelvis or breastbone. A pathologist views the sample under a microscope to look for abnormal cells.
Cytogenetic analysis: A laboratory test in which a sample of blood or bone marrow are analyze for the number of chromosomes, and whether they have had changes such as broken, missing, rearranged, or extra chromosomes. Changes in certain chromosomes can be a sign of cancer in some patients. Cytogenetic analysis is used to help diagnose cancer, plan treatment, or monitor how well the current treatment is working.
Gene mutation test: A laboratory test done on a bone marrow or blood sample to check for mutations in JAK2, MPL, or CALR genes, which are found in a majority of all MPNs. For example, a JAK2 gene mutation is often found in patients with PV, ET, or MPF. MPL or CALR gene mutations are found in patients with ET or PMF.
How Do You Treat Myeloproliferative Neoplasms?
Treatment options for MPNs vary depending on the type of disorder and results from other staging tests. Patients should consult their doctor to determine which treatment option is best for their cancer case, which can largely depend on the symptoms and type of MPN you have. Common treatment options include:
- Active surveillance or watchful waiting for patients with no symptoms
- Radiation therapy
- Targeted therapies such as ruxolitinib
- Platelet apheresis
- Bone marrow/stem cell transplant
- Other palliative care treatments depending on symptoms
Clinical trials are also an option for patients who have an MPN. Participation in a clinical trial may help advance cancer research, while also helping other patients who are experiencing the same disease. We can help patients find, qualify, and enroll into a clinical trial.
Are Myeloproliferative Neoplasms Hereditary?
It is believed that 5-10 percent of MPN cases have a family history of at least one relative with an MPN. It is unknown by researchers how the family history increases one’s risk of developing an MPN because the mutation leading to MPNs are acquired over time and not inherited.
What Are the Symptoms of Myeloproliferative Neoplasms?
MPNs are indolent (slow-growing) and do not cause symptoms in some patients. Those at risk of an MPN might ask “What are the early signs of Myeloproliferative Neoplasms?”. There are several factors such as the patient’s age and which type of MPN is present.
Patients with MPNs may experience symptoms including:
- Persistent headaches
- Frequent infections
- Easy bruising and bleeding
- Blurred vision
The specific type of MPN and which symptoms are experienced are the two biggest factors for whether patients need treatment.
How Long Can You Live with Myeloproliferative Neoplasms?
The survival rate for MPNs depends on several factors such as the patient’s age at diagnosis, symptoms present, and which type of MPN they have. The overall survival rates of MPNs are:
- Polycythemia vera (PV): The median age at diagnosis is 60 for PV. The 5-year survival rate for PV is 85 percent. However, 25 years after the diagnosis there is only a 20 percent survival rate, compared to the 55 percent survival rate for healthy, matched people.
- Essential thrombocythemia (ET): The median age at diagnosis is
f50-60. The 5-year survival is equivalent to matched, healthy people whereas the 25-year survival is 40 percent compared to 55 percent for healthy, matched individuals.
- Primary myelofibrosis (PMF): The median age at diagnosis is between 65 and 70 years old. The 5-year survival rate is 55 percent. After 25 years the survival rate in healthy people is 55 percent, whereas it is 10 percent for those with PMF. Only 5 percent of MPN patients have PMF.
- Chronic Myelogenous Leukemia (CML): The CML 5-year survival rate is 90 percent. Before targeted therapies were used in treatment, the survival rate was only 22 percent.
- Chronic eosinophilic leukemia/hypereosinophilic syndrome (HES): The HES 5-year survival rate is 90 percent. Before targeted therapies were used in treatment, the survival rate was only 12 percent after 3 years.
- Chronic neutrophilic leukemia (CNL): Most patients with CNL have a poor prognosis, with a mean survival time of 21 months. However, CNL is extremely rare with only 200 diagnoses ever.