Myelofibrosis

Myelofibrosis (MF) is a blood cancer where scar tissue builds up in your bone marrow. This reduces its ability to make blood cells. Bone marrow is the soft, spongy tissue inside your bones. It makes stem cells that mature into red blood cells, white blood cells or platelets.

With MF, a change in the stem cell’s genes causes it to become a cancer cell that multiplies fast. The cancer causes inflammation that creates scar tissue. The damage makes it harder for your bone marrow to make healthy blood cells. Meanwhile, your spleen (which filters abnormal blood cells) becomes overworked. It can enlarge and cause symptoms.

Myelofibrosis (pronounced “my-low-fi-BRO-sus”) is a lifelong condition that often progresses slowly. But sometimes, it gets worse fast. In some cases, it transforms into an aggressive type of acute leukemia. This is why your healthcare provider will manage your care closely once you’re diagnosed.

Types of this condition

There are two types of myelofibrosis:

• Primary myelofibrosis occurs on its own. It’s the most common type.
• Secondary myelofibrosis or Post-ET/PV MF occurs when essential thrombocythemia or polycythemia vera progresses. These conditions are myeloproliferative neoplasms (MPNs). MPNs are blood cancers where your bone marrow makes too many blood cells. Primary myelofibrosis is also an MPN.

Symptoms of myelofibrosis

Myelofibrosis often gets worse slowly. You may not have symptoms for years. When symptoms do start, the first to show are usually severe fatigue (a sign of anemia) and an enlarged spleen. An enlarged spleen may feel like heaviness in your upper left abdomen. Or the area may hurt.

Other signs and symptoms include:

• Bone and joint pain
• Easy bruising or bleeding
• Enlarged liver
• Fever
• Getting infections easily
• Feeling full when you haven’t eaten much
• Itching
• Night sweats
• Problems concentrating
• Unexplained weight loss

Myelofibrosis causes

Primary myelofibrosis happens when the earliest form of a blood cell — a stem cell — transforms into a cancer cell. The cell makes malignant copies (clones) that build up in your bone marrow.

The clones crowd out healthy blood cells. They also release substances that damage your bone marrow. The damage leads to scarring inside your bones.

Doctors don’t know what causes this process in the first place. But they do know that many people with MF have common genetic mutations. A mutation is a change in a gene. The most common ones are:

• JAK2
• CALR
• MPL

Risk factors

You may be at increased risk of myelofibrosis if:

• You’re over 60
• You have primary thrombocytosis or polycythemia vera
• You’ve been exposed to large doses of ionizing radiation (rare)
• You’ve been exposed to high levels of industrial chemicals like benzene (rare)

Complications of this condition

As myelofibrosis advances, it can lead to:

• Decreased blood cell production: The scar tissue can crowd out the normal cells in your bone marrow. This can lead to anemia or low platelets.
• Blood cell production outside of your bone marrow: Blood cells unable to form in your bone marrow may develop in your spleen, liver or other organs.
• High blood pressure in your portal vein: Your portal vein carries blood from your spleen to your liver. Tumors from the out-of-place blood cells can put too much pressure on this vein. This can cause serious bleeding.
• Acute myeloid leukemia (AML): MF can progress to AML. This is the most aggressive form of leukemia.

How doctors diagnose this condition

Your healthcare provider will do a physical exam and review your medical history. They’ll ask about your symptoms. Tests you may need include:

• Blood tests: They’ll check for abnormal blood cell counts and cells that look atypical. They’ll also check for levels in your blood that may mean an organ is stressed.
• Imaging tests: A CT scan or ultrasound can show if your spleen or liver is enlarged. An MRI can show scarring in your bone marrow.
• Bone marrow biopsy: A provider will analyze cells from your bone marrow to check for cancer. They’ll test for common gene mutations in MF.

Staging and risk scoring

As part of your diagnosis, your healthcare provider may stage MF as either prefibrotic (early) or overt (advanced). Prefibrotic MF involves less scarring in your bone marrow than overt MF.

Your provider may also score your MF. Scoring systems for MF consider your symptoms, test results and the type of mutation. The results range from low- to intermediate- to high-risk. This helps providers estimate your life expectancy after treatment.

Low-risk MF typically requires less-intensive treatments than high-risk MF.

How is myelofibrosis treated?

You don’t need treatment if you have low-risk MF and aren’t symptomatic. Instead, your healthcare provider will monitor you.

Common medications used to treat intermediate- and high-risk myelofibrosis include JAK inhibitors like:

• Fedratinib (Inrebic^®)
• Momelotinib (Ojjaara^®)
• Pacritinib (Vonjo^®)
• Ruxolitinib (Jakafi^®)

For most people, the goal of treatment is to manage conditions that cause symptoms. Treatment may also slow disease progression.

Anemia treatments

Treatments that manage anemia include:

• Medications, including androgens, chemotherapy drugs, immunomodulators, corticosteroids and human-made forms of erythropoietin (medicines that aid red blood cell production)
• Blood transfusions

Enlarged spleen treatments

Treatments for an enlarged spleen include:

• Medications, including chemotherapy drugs and immunomodulators or targeted therapy (like JAK inhibitors)
• Radiation therapy directed at your spleen (rarely)
• Surgery to remove your spleen (very rarely)

Stem cell transplant

A hematopoietic stem cell transplant (HCT) is a potential cure for MF. For some people, it’s not a cure, but it helps them live longer. Still, an HCT is a risky procedure with potentially fatal complications. It’s not an option for everyone. Instead, healthcare providers recommend it for people who are diagnosed as high risk.

This procedure involves replacing abnormal stem cells with healthy cells from a donor.

When should I see my healthcare provider?

Your provider will monitor you regularly. In the meantime, let them know what symptoms you’re experiencing. Report any treatment-related side effects you have.

What is the life expectancy for someone with myelofibrosis?

People with more advanced scarring in their bone marrow live about three to seven years after diagnosis. People with prefibrotic (early) MF live for about 10 to 15 years. About 20 out of every 100 people with primary MF develop acute myeloid leukemia within 10 years of their diagnosis.

But it’s important to remember that your prognosis (outlook) depends on lots of things. Your stage, risk score, the type of genetic mutations you have — they’re just some of the factors that matter.

Ask your provider about what your diagnosis means for your experience of the disease.

Is there anything I can do to feel better?

Ask your healthcare provider if you could benefit from palliative care. Palliative care specialists can help you navigate the challenges of a cancer diagnosis. Unlike hospice care, these providers can help people with chronic illnesses, no matter their prognosis.

You can also ask your provider if you’re a candidate for a clinical trial. Clinical trials study the safety and effectiveness of new treatments. Doctors continue to discover new therapies that are improving the lives of people with MF.