American Medical Association Family Medical Guide - American Medical Association [374]
Acute Lymphocytic Leukemia
Acute lymphocytic leukemia (ALL) is characterized by an excess of infection-fighting white blood cells called lymphocytes in the blood and bone marrow. Lymphocytes originate in the bone marrow and other organs of the lymphatic system. In ALL, immature lymphocytes, called lymphoblasts, do not develop into infection-fighting white blood cells as they should. Excessive numbers of these immature lymphocytes collect in the blood, bone marrow, and lymph tissues. If the cancerous cells crowd out other blood cells, including red blood cells (which carry oxygen) and platelets (which enable blood to clot), the bone marrow cannot produce these essential cells in adequate numbers. A deficiency of red blood cells can lead to anemia; a deficiency of platelets can lead to easy bleeding or bruising.
The cancerous lymphocytes can also spread to other organs, including the brain, and to the spinal cord. ALL progresses quickly and affects mostly children and young adults. The prognosis for a person with ALL depends on the person’s age and general health, on the characteristics of the leukemia cells seen under a microscope, and on how well the cancer responds to treatment.
Symptoms
The early symptoms of ALL—fever, weakness, fatigue, aching in the bones or joints, and swollen lymph nodes—are similar to those of the flu and other common infections. See your doctor if you have any of these symptoms for more than 2 or 3 weeks.
Diagnosis
Because symptoms in the early stages of ALL can resemble those of the flu, the disease can be difficult to diagnose. If you have persistent symptoms, your doctor may order blood tests to measure the levels of the different kinds of cells in your blood. If the results are abnormal, the doctor may recommend a bone marrow biopsy in which a small sample of your bone marrow is withdrawn through a needle inserted into a bone and the cells are studied under a microscope. The doctor may also recommend a lumbar puncture (see page 693), in which a needle is inserted through your back into the lower part of the spinal canal to withdraw a sample of cerebrospinal fluid; the fluid is studied under a microscope for the presence of cancerous cells. This information can help the doctor determine the type of leukemia and the best treatment.
Leukemia
In lymphocytic leukemias, white blood cells called lymphocytes have a genetic mutation that makes them abnormal. These abnormal lymphocytes don’t function as they should to fight infections and they multiply and stay alive longer than usual, crowding out healthy cells and potentially disrupting the functioning of organs throughout the body.
Treatment
Chemotherapy (see page 23) is the standard treatment for ALL. Chemotherapy may be given by pill, injected into a vein or muscle, or injected into the cerebrospinal fluid through a needle inserted into the brain or back (to prevent the spread of cancer cells into the spinal fluid). If the cancer cells have spread to the spinal fluid, you will be given additional radiation therapy (see page 23) or chemotherapy in the brain. Once the cancer is in remission and you no longer have any signs of leukemia, you may receive chemotherapy for several years to kill any remaining cancer cells and to keep the cancer from recurring. If the leukemia recurs, you may choose to participate in a clinical trial of a stem cell transplant (see next page). In some cases, a stem cell transplant is recommended as the initial treatment for ALL.
Chronic Myeloid Leukemia
Chronic myeloid leukemia (CML) results