Acute Monocytic Leukemia

What is acute monocytic leukemia?

Acute monocytic leukemia (AMoL) is a type of acute myeloid leukemia (AML). Like all forms of leukemia, AMoL is a blood cancer. It happens when there’s a problem with blood cell development. Instead of becoming healthy blood cells, the still-developing cells transform into abnormal cancer cells.

With AMoL, the immature cells, or blasts, are on a path to becoming white blood cells called monocytes. But instead, they get stuck in the immature or blast form.

Acute monocytic leukemia is a serious and aggressive cancer. Your healthcare provider will work with you to find the best treatments based on your situation.

Types of acute monocytic leukemia

The World Health Organization (WHO) classifies AMoL based on the type of cells that turn cancerous (monocytes). Acute monocytic leukemia is also known as AML-M5 according to the French-American-British (FAB) Classification system. This system further divides AML-M5 into two groups:

• Acute monoblastic leukemia (AML-M5a). At least 80% of the cells turn cancerous before they finish developing. This type is most common in children and young adults.
• Acute monocytic leukemia (AML-M5b). Most of the abnormal cells were at a more advanced stage of cell development before becoming cancerous. This type doesn’t impact one age group more than another.

These classifications help healthcare providers diagnose the condition. But one type isn’t more serious than another.

What are the symptoms of acute monocytic leukemia?

Symptoms of AMoL are often noticeable and get worse fast. They include:

• Easy bruising and bleeding (including bleeding gums and frequent nosebleeds)
• Purple, red or brown dots beneath your skin (petechiae)
• Swollen gums or an overgrowth of gum tissue
• Weakness and fatigue
• Shortness of breath
• Loss of appetite
• Unexplained weight loss
• Pale skin
• Dizziness
• Fever

Acute monocytic leukemia can often involve your brain and central nervous system. If it does, you may notice related symptoms, like trouble remembering or focusing.

What causes AMoL?

Medical experts don’t know what causes AMoL. But it likely involves genetic mutations (changes) in cell DNA. These changes cause a healthy cell to become cancerous.

Researchers have found that in some people with AMoL, there’s a mix-up involving genetic material called chromosomes. One piece of a chromosome breaks off and attaches to a different chromosome. This is called chromosomal translocation. The mix-up may cause a cell to stop developing into a monocyte and become a cancer cell instead.

Research into these gene changes is ongoing. Understanding the genetics behind cancer helps experts develop better treatments to fight it.

Risk factors

Factors that may increase your risk of acute monocytic leukemia include:

• Smoking and being around secondhand smoke
• Previous cancer treatments, like chemotherapy and radiation therapy
• Long-term exposure to cancer-causing toxins (carcinogens), like benzene and formaldehyde
• Radiation exposure after a nuclear reactor accident or atomic bomb
• Genetic disorders you inherit, like Li-Fraumeni syndrome
• Bone marrow diseases, including myeloproliferative neoplasms

It’s important to remember that having a risk factor doesn’t mean you’ll get cancer. Still, it’s a good idea to avoid risks you can control, like choosing not to smoke.

What are the complications of AMoL?

With AMoL, too many abnormal cells can build up in your bone marrow. This is where blood cells get made. The cancer cells can crowd out your healthy blood cells. This can lead to low red blood cells, white blood cells and platelets, leading to complications like:

• Anemia
• Neutropenia
• Thrombocytopenia

How is acute monocytic leukemia diagnosed?

Healthcare providers use a series of tests to diagnose AMoL. According to the World Health Organization, a person has AMoL when 20% or more of their blood cells are abnormal, immature cells. More than 80% of the abnormal cells have to be monocytes or early forms of monocytes.

Your provider will draw blood or take samples of fluid, tissue or bone marrow. The actual analysis happens behind the in a lab.

Tests to diagnose AMoL include:

• Blood tests. A complete blood count (CBC) can reveal signs of AMoL, like a high white blood cell count. A peripheral blood smear can show if cells look abnormal.
• Bone marrow biopsy. For this test, your provider takes a sample of tissue or fluid from a bone (usually in your hip). Then, they’ll use a microscope to check for cancer cells.
• Spinal tap. Your provider takes spinal fluid for testing to see if cancer cells have spread to your brain or central nervous system.
• Immunophenotyping. This test checks for specific proteins on the cells’ surface. These proteins help identify the cells as AMoL.
• Cytogenic analysis. This type of analysis checks the chromosomes inside cells for translocations (mix-ups) associated with AMoL.

How is acute monocytic leukemia treated?

The goals of treatment are to put cancer into remission. This means you no longer have cancer cells in your bone marrow or blood. This isn’t the same as a cure, which means the cancer is gone and won’t come back.

Chemotherapy

Chemotherapy is the main treatment for acute monocytic leukemia. It involves:

• Induction therapy. This treatment uses a combination of chemotherapy drugs to send AMoL into remission. Treatment usually involves repeat visits that span several days.
• Consolidation therapy. In this treatment, you’ll continue to receive high-dose chemo to kill any remaining cancer cells. It reduces the chance that the cancer cells will come back. Treatment usually happens for several days for three to four months.
• Maintenance therapy. You may need low-dose chemo for several months or years after consolidation therapy.

Targeted therapy

This treatment targets specific mutations (changes) in cancer cells. You may need targeted therapy if chemotherapy hasn’t worked. Or you may get targeted therapy if the cancer cells have a specific genetic mutation that a targeted therapy drug treats.

Stem cell transplant

The only way to cure acute monocytic leukemia is with an allogeneic stem cell transplant. You may need one after you are in remission. Or you may get a transplant if the cancer comes back after remission. During the procedure, a provider replaces your stem cells with stem cells from a donor. Usually, a donor is a close relative with a matching blood type. They may also be an unrelated donor from a national or international registry.

Not everyone is a candidate for a stem cell transplant. And it can cause serious side effects. Your healthcare provider can explain the benefits and risks if they’re recommending it.

Clinical trials

A clinical trial is a study that tests the safety and effectiveness of new treatments. Depending on your diagnosis, it may be the best treatment for you. Ask your healthcare provider if they think you should participate in a clinical trial.

What can I expect if I have this condition?

The outlook for acute monocytic leukemia (AMoL) is similar to acute myeloid leukemia in general (AML) in general. About 3 people in 10 with AMoL are alive five years after they’re diagnosed.

Still, it’s important to remember that these numbers don’t reflect new treatments. And new treatments are helping people live longer with AMoL. Also, your prognosis (likely outcome) depends on several factors, including your:

• Age. AMoL has a better outlook in people under 65.
• White blood cell counts. AMoL has a better outlook in people who don’t have very high white blood cell counts.
• Response to treatment. AMoL has a better outlook if induction chemotherapy leads to remission.

How do I take care of myself?

Living with leukemia is stressful. Even after remission, you may have to cope with concerns that the cancer may come back. You may have to manage long-term side effects of cancer treatment. The best way to take care of yourself is to take advantage of every available resource. This may include:

• Cancer survivorship programs. Connecting with others with cancer can provide much-needed support and assurance that you’re not alone.
• Palliative care. Palliative care can help you manage symptoms of cancer and cancer treatment. It’s an excellent resource no matter your prognosis.
• Therapy. Many people with cancer develop anxiety and depression. Meeting with a mental health professional who works with cancer survivors can help. A therapist can help you manage the daily stressors that can go along with a cancer diagnosis.

When should I see my healthcare provider?

You’ll see your healthcare provider regularly to monitor your response to treatment. They’ll let you know what changes in your body to look out for that may be signs the cancer is coming back.

What questions should I ask my healthcare provider?

Questions to ask include:

• Which treatments will I need?
• Which side effects should I expect, and how can I manage them?
• Should I take part in a clinical trial?
• How often will I need follow-up appointments?
• What resources are available that can help me?