What is Chronic Myelomonocytic Leukemia or CMML?
Chronic myelomonocytic leukemia (CMML) starts in the bone marrow bone marrow: The soft, spongy tissue inside most bones. Blood cells are formed in the bone marrow. and then moves to the blood. It happens when monocytes in the bone marrow begin to grow out of control, filling the bone marrow and preventing other blood cells from growing.
CMML is rare, occurring in about 4 of every 1 million people in the U.S. each year, with about 1,100 new cases diagnosed annually. About 9 out of 10 cases are found in people 60 and older. CMML occurs more often in men than in women and is very rare in young people.
Relation to bone marrow failure diseases:
CMML used to be considered a type of myelodysplastic syndrome (MDS) because patients have abnormal-looking (dysplastic) cells in their bone marrow. But other factors associated with CMML didn't match the definition of MDS. Instead, they more closely resembled myeloproliferative neoplasms, a group of diseases where the bone marrow makes too many cells. Since CMML has features of both myelodysplastic syndrome and myeloproliferative neoplasm, experts created a new “overlap” category of myelodysplastic/myeloproliferative neoplasm.
Between 15 and 30 percent of CMML patients go on to develop acute myeloid leukemia acute myeloid leukemia: (uh-KYOOT my-uh-LOYD loo-KEE-mee-uh) A cancer of the blood cells. It happens when very young white blood cells (blasts) in the bone marrow fail to mature. The blast cells stay in the bone marrow and become to numerous. This slows production of red blood cells and platelets. Some cases of MDS become… (AML).
What causes CMML?
The exact cause of CMML is not known. There are, however, known risk factors that increase the chances of getting CMML. They include:
- Older age (60 or older)
- Being male
- Being exposed to certain chemicals at work or in the environment
- Being exposed to radiation
- Past treatment with certain anticancer drugs
What are the symptoms of CMML?
The most common sign of chronic myelomonocytic leukemia (CMML) is having too many monocytes, a type of white blood cell white blood cell: Cells in the body that fight disease and infection by attacking and killing germs. There are several types of white blood cells including neutrophils, eosinophils, basophils, lymphocytes and monocytes. Each type of cell fights a different kind of germ. Also called WBC, leukocyte. , in the blood. These cells can settle in the liver and spleen, causing them to enlarge. They can also cause the bone marrow to make less of other blood cells, resulting in:
- A low number of red blood cells (anemia) that can lead to feeling very tired, shortness of breath and pale skin
- A low number of normal white blood cells (leukopenia) that can lead to a fever and frequent or severe infections or, in some cases, a more normal number of white cells but they are ineffective.
- A low number of blood platelets (thrombocytopenia) that can lead to problems with easy bruising and bleeding, frequent or severe nosebleeds or bleeding from the gums.
How do you diagnose CMML?
There are a number of tests and tools doctors use to confirm a CMML diagnosis:
- Physical exam and history
- Blood tests include:
- Complete blood count with a differential looks at the total number and type of blood cells in your blood
- A blood smear allows your doctor to look at your blood under a microscope
- Blood tests to look for other causes of low blood counts, such as low levels of vitamin b12 vitamin b12: A complex vitamin found in animal products. Vitamin B12 helps maintain healthy red blood cells and nerve cells. A shortage of Vitamin B12 and folate can reduce blood cell production in the bone marrow. Also called B complex vitamin. and folate folate: (FOE-late) A B-vitamin that is found in fresh or lightly cooked green vegetables. It helps the bone marrow make normal blood cells. Most people get enough folate in their diet. Doctors may have people with paroxysmal nocturnal hemaglobinuria (PNH) take a man-made form of folate called folic acid.
- Bone marrow aspiration Bone marrow aspiration: A medical procedure to remove of a small amount of liquid bone marrow through a needle inserted into the back of the hip. The liquid bone marrow is examined for abnormalities in cell size, shape, or look. Tests may also be run on the bone marrow cells to look for any genetic abnormalities. and biopsy to see how your bone monocytes in your bone marrow look (required for diagnosis)
- Cytogenetic testing looks at abnormalities in your cell DNA may also be done.
What is the treatment for CMML?
Treatment of CMML depends on how severe the disease is, as well as the patient’s age and health. Treatment options include:
- Supportive care Supportive care: Care given to improve the quality of life, or comfort, of a person with a chronic illness. Supportive care treats the symptoms rather than the underlying cause of a disease. The goal is to help the patient feel better. Patients with low blood counts may be given blood transfusions as supportive… with blood transfusions blood transfusions: A blood transfusion is a safe and common procedure. Most people who have a bone marrow failure disease like aplastic anemia, MDS or PNH will receive at least one blood transfusion. When you receive a blood transfusion, parts of blood from a donor are put into your bloodstream. This can help some… , growth factors growth factors: Growth factors are naturally occurring hormones in your body that signal your bone marrow to make more of certain types of blood cells. Man-made growth factors may be given to some people with bone marrow failure diseases to help increase red blood cell, white blood cell or platelet counts. Red… and antibiotics antibiotics: The most common white blood cells are called neutrophils. They fight infection. Patients who don't have enough healthy neutrophils are said to have neutropenia. Because of their low white count, they may get infections easily and have trouble getting rid of infections. If you have neutropenia,… to treat symptoms by increasing blood counts and stopping infections
- Chemotherapy Chemotherapy: (kee-moe-THER-uh-pee) The use of medicines that kill cells (cytotoxic agents). People with high-risk or intermediate-2 risk myelodysplastic syndrome (MDS) may be given chemotherapy to kill bone marrow cells that have an abnormal size, shape, or look. Chemotherapy hurts healthy cells along with… to kill cells cancer cells using cytotoxic agents
- Radiation therapy with high-energy rays or particles to destroy cancer cells
- Stem cell transplant, which replaces blood-forming stem cells stem cells: Cells in the body that develop into other cells. There are two main sources of stem cells. Embryonic stem cells come from human embryos and are used in medical research. Adult stem cells in the body repair and maintain the organ or tissue in which they are found. Blood-forming (hemapoietic) stem… in your bone marrow with healthy stem cells from a donor
Clinical trials Clinical trials: Clinical research is at the heart of all medical advances, identifying new ways to prevent, detect or treat disease. If you have a bone marrow failure disease, you may want to consider taking part in a clinical trial, also called a research study. Understanding Clinical Trials Clinical… , also called research studies may offer good treatment options for some people with CMML. These studies also help researchers better understand the value of promising new treatments or procedures.