About Your Diagnosis

Chronic myelogenous leukemia (CML) is cancer of the white blood cells. The cause of CML is unknown, but it has been linked to exposure to benzene and high doses of radiation. CML cells contain an abnormal shift of DNA between two chromosomes (BCR-ABL translocation). In most patients, this rearrangement takes the form of an abnormal chromosome called the Philadelphia chromosome. About 20% of cases of leukemia among adults are CML. CML occurs among persons of all ages, but is most common in middle age. CML is not contagious and usually is not hereditary. Both the BCR-ABL translocation and the Philadelphia chromosome can be detected with special tests performed on the blood or bone marrow. These tests are used to diagnose CML. The only cure for CML is replacing the patient’s abnormal bone marrow with marrow from a healthy donor (allogeneic bone marrow transplantation). Other treatment options exist that can improve symptoms and prolong the life of patients with CML.

Living With Your Diagnosis
Patients with chronic phase CML usually have no restrictions on their lifestyle. CML originates in the bone marrow, where blood cells are formed. Three types of blood cells normally are formed in the marrow—red blood cells, which carry oxygen; white blood cells, which fight infection; and platelets, which assist in clotting. CML cells multiply in the marrow, slowly crowd out the normal cells, and then enter the peripheral blood. The blood of a patient with CML usually contains an increased number of abnormal, immature white blood cells, which are affected by CML. There are three stages of CML—a chronic phase, an accelerated phase, and an advanced phase known as blast crisis. With CML in the chronic phase, which may persist for years, patients have relatively few symptoms. The disease is diagnosed when a routine blood test reveals a high white blood cell count. The platelet count also may be elevated in chronic-phase CML. Some patients with chronicphase CML may feel abdominal fullness becauseof growth of the spleen in the left upper abdomen. Rare patients may have fatigue, weight loss, fever, night sweats, or bone pain. The foregoing symptoms generally become more prominent in the accelerated phase of CML. As CML accelerates, the malignant cells overgrow the normal blood cells in the bone marrow, leading to anemia (low red blood cell count) and thrombocytopenia (low platelet count). Symptoms of anemia include fatigue, dizziness, and shortness of breath; symptoms of thrombocytopenia include increased bleeding. As the disease progresses, the white blood cells in the blood and marrow become progressively more immature. These immature white blood cells cannot fight infections properly, making some patients with CML highly susceptible to infections. The most immature type of white blood cell is called a myeloblast. When most of the white blood cells in the blood or marrow of a patient with CML are myeloblasts, the patient is said to have advanced CML or blast crisis. Patients with advanced CML may have very high numbers of immature white blood cells in their blood. If the number of these cells does not decrease (usually with medication), the cells may become stuck in various parts of the body, most notably the lungs, brain, or penis. Patients with advanced CML who experience sudden, severe headaches, shortness of breath, or an erection unassociated with sexual arousal should call their physicians immediately.

Treatment
The only cure for CML is replacing the patient’s abnormal bone marrow with marrow from a healthy donor (allogeneic bone marrow transplantation). In most cases, the donor is a close relative, usually a brother or sister, whose marrow is genetically similar to the patient’s. Patients who do not have a relative whose marrow matches theirs can sometimes find a match from a national list of voluntary bone marrow donors. Bone marrow transplantation is a long process that takes place in a hospital. First the patient’s marrow is destroyed with high doses of chemotherapy or radiation. After a few days, the patient receives the healthy marrow through an intravenous catheter. The marrow finds its way into the bones and begins making normal blood cells. The patient remains in the hospital until the new marrow has made enough cells to perform most of the functions of the blood, usually about 4 weeks. Bone marrow transplantation is most effective performed soon after the diagnosis of CML is made. More than half of patients who undergo transplantation while the disease is in the chronic phase are alive and disease-free 5 years after transplantation. The results are poorer for patients who undergo transplantation while the disease is in the accelerated phase or blast crisis. Results also are better for patients who undergo transplantation early in the chronic phase than for patients who have had CML for more than 1 year. There are many side effects of bone marrow transplantation. The chemotherapy or radiation therapy causes hair loss and mouth sores. Patients need transfusions of red blood cells and platelets for the first few weeks after bone marrow transplantation, because the new marrow has not yet made enough of these cells. Patients also are at increased risk for infection for the first few months after bone marrow transplantation, and most patients need medications to prevent or manage these infections. The most common complication of bone marrow transplantation is infection. Another complication is graft-versus-host disease. In graft-versus-host disease, the new marrow recognizes the patient’s body as foreign and attacks it. Patients who undergo bone marrow transplantation take medications to prevent graft-versus-host disease; new medications are added if graft-versus-host disease still occurs. The number and severity of complications of bone marrow transplantation usually increase as the patient’s age increases. Many hospitals do not perform bone marrow transplantation on patients older than 50 years. Although bone marrow transplantation is the only cure for CML, many patients with CML cannot undergo this treatment, either because of their age or because of inability to obtain matched bone marrow. These patients receive treatments to improve the symptoms of the disease and increase the length of the chronic phase. The most commonly used treatment is interferon-alfa (IFNa), which is given by means of daily injection under the skin. Most patients who receive IFNa normalize their blood counts and spleen size. Some patients actually decrease or eliminate CML cells in their bone marrow, measured by means of determining the percentage of cells with the Philadelphia chromosome. Patients who eliminate CML cells from their marrow live longer than patients who do not. All patients who take IFNa experience a flu-like syndrome immediately after beginning treatment. This improves after a few weeks. The most serious complication of taking IFNa is impairment of concentration and memory. Patients with these symptoms should inform their physician and stop IFNa therapy immediately.

The DOs
• Participate in your chemotherapy regimen as determined by your physician.
• Eat a healthy balanced diet, unless you have neutropenia.
• Use caution in exercise.
• Receive a vaccination against the influenza virus every fall.
• Brush your teeth with a soft toothbrush and shave only with an electric razor if you have accelerated or advanced CML.
• Stop exercise at once if you experience dizziness, pain, or shortness of breath.

The DON’Ts
• Avoid uncooked fruits, vegetables, and milk products if you have neutropenia (low white blood cell count). These foods can harbor bacteria that are not dangerous to healthy persons but can cause an infection if you have neutropenia.
• Avoid contact sports if your platelet count is so low you are at increased risk for bleeding.

When to Call Your Doctor
• If you experience unexplained fatigue, weight loss, or left upper abdominal pain; these symptoms may indicate progression to the accelerated phase.
• If you have a fever. Fever can indicate either infection or progression of CML.
• If you have any bleeding that does not resolve after pressure is applied to the area for 5 minutes.
• If you have sudden severe headaches, shortness of breath, or an erection unassociated with sexual arousal.