A myelodysplastic syndrome is a disease of the bone marrow that eventually progresses into leukemia, a type of cancer. While 1 curative option for myelodysplastic syndromes is a procedure called a stem cell transplantation, not all persons are able to tolerate the potentially life-threatening complications that can occur with this procedure. For these persons, treatment is focused on providing biologic agents that help the bone marrow produce more normal blood cells, relieve the signs and symptoms of disease, and prolong survival time. Now, researchers say that blood cell counts may be better enhanced using a combination of 2 agents, granulocyte macrophage colony-stimulating factor (GM-CSF) and erythropoietin.
A myelodysplastic syndrome is a disease in which the cells in a person’s bone marrow are not functioning normally. This condition is sometimes referred to as a pre-leukemia or “smoldering” leukemia, because it often develops into leukemia, which is a type of cancer. The bone marrow (and circulating blood) contains early blood-forming cells, called
stem cells, which grow and mature into the 3 blood cell types: white blood cells (protect the body from infection), red blood cells (carry oxygen to the tissues), and platelets (help the blood to clot). In the case of myelodysplastic syndromes, not enough normal blood cells are being produced. The term
anemia is used to describe the deficiency in red blood cells that results in some persons with myelodysplastic syndromes.
Treatment of myelodysplastic syndromes often consists of the infusion of red blood cells or platelets to compensate for the inadequate production of these cells in the bone marrow. An agent called GM-CSF, a growth factor, is often used to help white blood cells grow. Another agent, called erythropoietin, is used to improve the production of red blood cells, usually only in persons who have low red blood cell counts. These therapies may ease the signs and symptoms of disease, such as anemia and fatigue, and may prolong survival time. The use of chemotherapy drugs and other biologic therapy agents (immunotherapy) are being studied in clinical trials. The use of high doses of chemotherapy and/or radiation therapy, followed by a stem cell transplantation, is an additional treatment option for persons who are strong enough to tolerate the transplant procedure.
Researchers from several medical centers studied whether GM-CSF alone or GM-CSF plus erythropoietin would be more effective in increasing blood cell growth in persons with myelodysplastic syndromes. They assigned 65 patients to receive either GM-CSF or GM-CSF plus erythropoietin for 12 weeks. The results showed that white blood cell counts increased in all patients. In addition, those receiving erythropoietin had an increase in their levels of hemoglobin, an iron-rich protein in the red blood cells that helps carry oxygen to the tissues. For this reason, these persons also needed fewer red blood cell transfusions than those receiving GM-CSF alone.
The researchers concluded that the combination of GM-CSF and erythropoietin is more beneficial than GM-CSF alone. They suggested that a 3-month trial of GM-CSF plus erythropoietin be given to persons who have a myelodysplastic syndrome, who rely on treatment with blood transfusions, and who are unable to withstand a stem cell transplantation. Persons who have a myelodysplastic syndrome may wish to talk with their doctor about the risks and benefits of the erythropoietin plus GM-CSF regimen, or of participating in a clinical trial in which other new treatments are being studied. Sources of information on ongoing clinical trials that can be discussed with a doctor include a comprehensive, easy-to-use service provided by the National Cancer Institute (cancer.gov) and the Clinical Trials section and service offered by CancerConsultants.com (www.411cancer.com). (Blood, Vol 95, No 4, pp 1175-1179, 2000)