What Is Myelofibrosis?
Myelofibrosis (MF) is a rare blood cancer that causes scar tissue to form in your bone marrow (the soft, spongy tissue inside your bones). It messes up how your body normally makes blood cells. MF is considered to be a form of chronic leukemia. Most people who get it are over the age of 50, but people of any age can have it. About 1.5 cases of myelofibrosis per 100,000 people are reported in the United States each year.
What Are the Symptoms of Myelofibrosis?
Myelofibrosis is often a slow-moving condition. Many people live with it for years without having any symptoms. When symptoms do happen, they can include:
- Fatigue and weakness, usually from anemia
- Shortness of breath
- Night sweats
- Fever
- Itching
- Bleeding for no known reason
- Weight loss
- Pain in bones or joints
- Easy bruising
- Infections
- Pain, or a feeling of “fullness” below your ribs on the left side
What Causes Myelofibrosis?
It’s not clear exactly what causes MF. Scientists do know that it’s often linked to DNA changes in certain genes. Research suggests one of three genes could be involved: JAK2 – which controls how your bone marrow makes blood cells – CALR, or MPL genes. Most people with MF have a change in the JAK2 gene.
In general, myelofibrosis is not passed down through families.
What Are the Different Types of Myelofibrosis?
There are two types of MF: primary and secondary myelofibrosis.
Primary myelofibrosis upsets how your body normally produces blood cells in a major way. It starts with changes in bone marrow stem cells. Those different stem cells then make copies and divide. This can cause scar tissue and a “crowding out” of healthy cells. It usually means you won’t have enough red blood cells, which causes anemia. This is the most common form of myelofibrosis.
Secondary myelofibrosis happens after you have other bone marrow disorders. Only about 10%-20% of people who have myelofibrosis have this type.
What Are the Risk Factors for Myelofibrosis?
Certain things can make you more likely to get myelofibrosis:
- You are over the age of 50.
- You come into contact with certain chemicals, such as benzene and toluene. Benzene is used to make plastics, detergents, drugs, and pesticides. Toluene is found in nail polish, paint thinner, glues, inks, and stain removers.
- You have primary thrombocytosis or polycythemia vera, both rare blood disorders.
- You’re exposed to ionizing radiation from X-rays or CAT scans, which can harm tissue and DNA in genes.
Myelofibrosis Diagnosis
Your oncologist (cancer doctor) will do some tests to find out whether you have MF, including:
- A physical exam to check your vital signs and talk about your medical history. Your doctor will be looking to see if there are any signs of anemia or an enlarged spleen.
- Blood tests, which are an important part of diagnosing myelofibrosis. A complete blood count (CBC) measures the number of your blood cells. If you have very low levels of red blood cells and your white blood cell and platelet counts are not normal, it could be a sign of myelofibrosis.
- Imaging tests, such as X-rays and MRI
- Bone marrow tests, which include:
- Bone marrow biopsy: Using a needle, your doctor takes a small sample of bone and marrow from your hip. They’ll examine it in a lab.
- Bone marrow aspiration: In this test, doctors use another type of needle to take fluid from your bone marrow and check blood cell levels.
Myelofibrosis Treatment
The treatment your doctor recommends will depend on when the cancer is found and how aggressive it is.
If your MF is caught early before you have any symptoms, it’s considered low-risk. You may only need to keep an eye on things with regular checkups. Some people are symptom-free for years.
If you do start having symptoms, your doctor may still just watch your condition. They might give you medication to lower blood cell counts.
Most people with MF are classified as intermediate-risk. Treatment focuses on managing symptoms to make your quality of life better.
In high-risk cases, aggressive treatment, including a bone marrow transplant, may be used. That involves using chemotherapy or radiation therapy to kill diseased blood-forming cells and replacing them with healthy stem cells from a donor.
The transplant comes with some life-threatening risks. So it may not be an option for older people. Talk to your doctor about the best course of treatment.
Treating myelofibrosis symptoms
Anemia
- Blood transfusions: Blood is given to you through a vein to replace blood or blood cells that are low. It should boost your red blood cell count and will help you get some of your energy back. A transfusion usually takes 1-3 hours. Afterward, your doctor will likely suggest a day or two of rest. Transfusions are thought to be routine and very safe. But talk to your health care team if you have concerns.
- Androgen therapy uses a lab-made version of the male hormone androgen. It may help your body make red blood cells to fight anemia.
- Medications such as thalidomide (Thalomid) and lenalidomide (Revlimid). A word of caution: Thalidomide and related drugs might cause serious birth defects.
Enlarged spleen
- Chemotherapy can ease pain and reduce the size of your spleen.
- Radiation treatment targets and destroys a cancer cell’s DNA. It can also help reduce the size of your spleen.
- Targeted drug therapy: The medicines fedratinib and ruxolitinib are FDA-approved for MF. They target the JAK genes that can cause problems in how blood cells are made. Both can be taken in pill form.
- Spleen removal (splenectomy): In most cases, doctors will perform “keyhole” surgery (laparoscopy), which is an operation that requires only small cuts. They’ll insert a tiny camera into the small cut in your belly area. The camera sends pictures to a video screen so the surgeon can do the operation. If your spleen has become too large, surgeons will have to make a larger cut to remove it. Just like with all surgeries, risks are involved.
What Are Some Complications of Myelofibrosis?
As myelofibrosis gets worse or progresses, you may get complications, including:
- Pain: Your spleen could get so large it causes serious back and belly pain.
- Higher blood pressure in your liver: This can cause too much blood in small veins in your stomach and throat, and may cause them to tear and bleed.
- Bleeding complications: Your platelet count drops, and that can lead to easy bleeding.
- Growths in other areas of your body: When blood cells form outside the bone marrow, tumors can grow. This could cause bleeding in your digestive system or seizures.
- Acute leukemia: This type of blood and bone marrow cancer, acute myelogenous leukemia, gets worse quickly.
Show Sources
Photo Credit: DigitalVision / Getty Images
SOURCES:
Cleveland Clinic: “Myelofibrosis,” “Splenectomy,” “Radiation Therapy for Cancer,” “Blood Transfusion,” “Thrombocytosis.”
Mayo Clinic: “Myelofibrosis Overview,” “Myelofibrosis Diagnosis,” “Fedratinib,” ”Ruxolitinib.”
National Library of Medicine: “Myelofibrosis,” “Novel therapeutics and targets in myelofibrosis.”
Leukemia & Lymphoma Society: “MF Disease Complications,” “MF Treatment.”
NORD (Rarediseases.org): “Primary Myelofibrosis.”
Cancer Research UK: “What is myelofibrosis?”
National Health Service (U.K.): “Laparoscopy.”
Wisconsin Department of Health Services: “Toluene,” “Benzene.”
CDC: “Radiation Studies.”
