UCSF Children's Hospital | Medical Services | Cancer and Blood Diseases

Myelodysplastic syndromes, also called pre-leukemia or "smoldering" leukemia, are diseases in which the bone marrow -- the spongy tissue inside the large bones -- does not function normally. Bone marrow cells called "blast" develop or mature into several different types of blood cells including red blood cells that carry oxygen and other materials to all tissues of the body; white blood cells that fight infection; and platelets that make the blood clot.

If cells in the bone marrow are injured or abnormal, they may behave abnormally. In myelodysplastic syndromes, the abnormality causes the bone marrow cells or blasts to develop into defective red cells, white cells and platelets. In acute myeloid leukemia, which is the more quickly advancing form of the disease, cells stop maturing altogether.

Myelodysplastic syndromes or acute myeloid leukemia may arise without any known cause or may be due to prior treatment with drugs or radiation for other diseases. Myelodysplastic syndromes occur most often in older people, but they also occur in children and young people.

The name myelodysplastic syndromes is based on how the bone marrow cells and blood cells appear under a microscope. There are five types of myelodysplastic syndromes:

The symptoms of myelodysplastic syndromes are caused by a shortage of cells ordinarily made by the bone marrow. Too few red cells causes anemia, which makes a child feel tired, unable to exercise, feel short of breath or experience headaches. A lack of white cells makes it hard for children to fight infections. Too few platelets may cause a child to bleed or bruise more easily. Often, myelodysplastic syndromes are diagnosed when children seem to suffering from anemia.

If your child experiences any symptoms of myelodysplastic syndromes, his or her doctor may order blood tests to count the number of each type of blood cell. If the results of the blood test are abnormal, the doctor may order a bone marrow biopsy. During this test, a needle is inserted into a bone and a small amount of bone marrow is removed and examined under a microscope. The doctor then can determine the disease and plan the best treatment.

Treatments include blood cell transfusions, chemotherapy, biological therapy and bone marrow transplants.

Often, the main treatment for myelodysplastic syndromes is a transfusion of red blood cells or platelets, administered intravenously by a needle in a vein, to control anemia or bleeding. Vitamins or other drugs also may be given to treat anemia.

Chemotherapy is the most well studied treatment for myelodysplastic syndromes. It is being improved in ongoing clinical trials at UCSF Medical Center and other major medical centers. Chemotherapy uses drugs to treat disease and may be taken by pill or it may be put into the body by a needle in the vein or muscle. Chemotherapy is called a systemic treatment because the drug enters the bloodstream, travels through the body and affects cells throughout the body. Because it affects cells throughout the body, chemotherapy has side effects that you should discuss with your child's doctor.

Biological therapy is a newer type of treatment that also is being tested in clinical trials for the treatment of myelodysplastic syndromes. Biological therapy tries to help the body fight disease. It uses materials made by the body or made in a laboratory to boost, direct or restore the body's natural defenses against disease. Biological therapy is sometimes called biological response modifier (BRM) therapy or immunotherapy. Because this therapy involves the body's defense mechanisms, treatments may have some side effects.

Bone marrow transplant (BMT) is another new type of treatment for myelodysplastic syndromes. It uses high doses of chemotherapy and sometimes radiation therapy, involving high doses of X-rays or other high-energy rays, to destroy all bone marrow in the body. After the existing bone marrow is destroyed, healthy bone marrow from a donor is transplanted back into your child. Healthy marrow comes from a donor whose tissue is the same or almost the same as your child's. The donor may be a twin, who would be the best match; a brother, sister or other relative; or an unrelated person. The healthy marrow is given to your child intravenously through a needle in the vein. A transplant using marrow from a relative or unrelated person is called an allogeneic bone marrow transplant.

Another type of bone marrow transplant -- called autologous bone marrow - uses a child's own bone marrow. But that treatment has not been found effective in treating myelodysplastic syndromes.