Unlike other types of cancer, leukemia isn't a tumor that your doctor can surgically remove. Leukemia cells are produced in the bone marrow and travel throughout the body.
The Goal of Treatment
The goal of treatment for leukemia is to destroy the leukemia cells and allow normal cells to form in the bone marrow. Depending on the type and extent of the disease, patients may have chemotherapy, biological therapy, radiation therapy, or stem cell transplantation. Some patients receive a combination of treatments.
Treatment depends on a number of factors, including the type of leukemia, the patient's age and general health, whether leukemia cells are present in the fluid around the brain or spinal cord, and whether the leukemia has been treated before. It also may depend on certain features of the leukemia cells and the patient's symptoms.
Acute Leukemia or Chronic Leukemia?
If a person has acute leukemia, they will need treatment right away. The purpose of treatment is to stop the rapid growth of leukemia cells and to bring about remission, meaning the cancer is under control. In many cases, a person will continue treatment after signs and symptoms disappear to prevent the disease from coming back. Some people with acute leukemia can be cured.
Chronic leukemia may not need to be treated until symptoms appear. Treatment can often control the disease and its symptoms. However, chronic leukemia can seldom be cured.
Chemotherapy uses drugs to kill cancer cells. This is the most common treatment for most types of leukemia. Chemotherapy may be taken by mouth in pill form, by injection directly into a vein, or through a catheter. If leukemia cells are found in the fluid around the brain or spinal cord, the doctor may inject drugs directly into the fluid to ensure that the drugs reach the leukemia cells in the brain.
Biological therapy uses special substances that improve the body's natural defenses against cancer. Some patients with chronic lymphocytic leukemia receive monoclonal antibodies, which are man-made proteins that can identify leukemia cells. Monoclonal antibodies bind to the cells and assist the body in killing them.
Although monoclonal antibodies are being used to treat leukemia, researchers are studying more innovative ways to use them in treatment. Some antibodies are used alone to try to prompt the immune system to attack leukemia cells. Other antibodies are attached to substances that can deliver poison to cancer cells. These modified antibodies, called immunotoxins, deliver the toxins directly to the cancer cells.
A natural substance called interferon is used to treat some patients with chronic myeloid leukemia. This substance can slow the growth of leukemia cells. Newer therapies target an enzyme responsible for the growth of the myeloid cells, and are very effective.
Radiation therapy uses high-energy X-rays to destroy cancer cells. A machine outside the body directs high-energy beams at the spleen, the brain, or other parts of the body where leukemia cells have collected. Radiation therapy is used primarily to control disease in bones that are at risk of fracture or at sites that are causing pain.
Stem Cell Transplantation
Stem cell transplantation uses high doses of chemotherapy and total body irradiation to kill the leukemia cells. After these treatments, the patient's immune system is usually very weak, because normal cells in the bone marrow are killed along with the leukemia cells. Healthy stem cells must be given to the patient to restore the immune system so it can fight infection and disease.
There are several types of stem cell transplantation.
- Bone marrow transplantation replaces a patient's bone marrow with leukemia-free stem cells from bone marrow.
- Peripheral stem cell transplantation uses stem cells that are collected from the bloodstream.
- Umbilical cord blood transplantation uses stem cells from a newborn baby.
Stem cells used for transplants come from the patient or a donor whose cells match the patient's cells. Use of the patient's own cells is called autologous stem cell transplantation. The cells are collected, treated to remove leukemia cells, and stored. After the patient receives high-dose chemotherapy or radiation treatment, their stored cells are returned to them.
Use of stem cells from a donor is called an allogeneic transplant. Allogeneic transplantation can be done using cells from a sibling or from another individual who has a similar immune system.