Advances in Treatment of Blood Cancer

Many advances have been made in the treatment of blood cancers in the past 30 years. Today, most types of lymphomas, leukemias and multiple myeloma can be effectively treated with chemotherapy and radiation therapy. Stem cell transplants are being done with increasing frequency across the country, and newer treatments, such as biological therapies, are being tested.

Stem cell transplant

Used more frequently to treat lymphoma and leukemia, this procedure gives very high doses of chemotherapy and/or irradiation and then "rescues" the patient with an infusion of stem cells from the bone marrow or peripheral blood. This procedure has tremendous risks, including death, and tends to be more successful in younger patients and when the disease is in an early stage. Because stem cell transplant for blood cancers is a specialized procedure, a transplant candidate should look for a hospital that has extensive experience treating his or her specific type of cancer and that performs stem cell transplants regularly.

There are three possibilities: autologous transplant, allogeneic transplant and syngeneic transplant. In an autologous transplant, the cancer patient donates his or her own stem cells for the transplant. The stem cells are collected either from the bone marrow or from peripheral blood and then frozen before the patient receives high doses of chemotherapy or radiation to treat the cancer. More commonly, peripheral blood stem cells are collected from the blood on a machine after chemotherapy and growth factors are given. After treatment, the cells are then injected back into the patient through a small tube inserted in a vein, replacing the cells that were destroyed. There is always the risk that some cancer cells remain in the stem cells that are being reintroduced. New ways of minimizing this risk by specially treating the stem cells with chemotherapy drugs are being tested.

An allogeneic transplant is one in which the stem cells are donated by another person whose genetic make-up matches the patient as closely as possible-usually a close relative such as a sibling or parent. Allogeneic transplants using matched unrelated donors are more commonly being performed now, although the transplant has significant risks. In a syngeneic transplant, the marrow is contributed by an identical twin, who is the perfect genetic match for the patient.

Side effects can be serious, painful and potentially lethal, and the risks can last several months. Rarely, rejection occurs when the patient's body recognizes the transplanted stem cells as foreign invaders and attacks them with the intent to destroy. Rejection can also occur in the reverse direction in a problem called graft-versus-host disease. Here, the transplanted stem cells recognize the patient's body as foreign and try to destroy it, causing anything from mild rashes to severe liver damage. Drugs to suppress this immune response are given, but they also make the patient even more prone to infection than before.

Another risk is veno-occlusive disease, a serious liver disease that occurs when liver cells try to clear away toxins and instead become poisoned and swollen, eventually causing jaundice when bile flow is stopped. About 20 percent of people who receive allogeneic transplants get this disease and about 5 percent to 6 percent of those affected die from it. Other side effects include those typical of strong chemotherapy drugs, such as extreme nausea and vomiting, fatigue and mouth sores.

Biological therapy

Biological therapy uses special immune system cells and proteins to stimulate the body's immune system to kill cancer cells. Biological agents such as interferons, interleukins, monoclonal antibodies, tumor necrosis factors and colony-stimulating factors are natural substances found in the body that help alter the way the immune system reacts to cancer. Researchers are now able to create reproductions of some of these biological agents in laboratories, imitating the natural immune agents. These agents are used to augment the anti-tumor immune response of the patient.

This type of treatment may be administered in a hospital and requires extensive follow-up. Side effects can be severe. The most common reactions include severe flu-like symptoms, fatigue, confusion, problems with heart rhythms, rashes and depression. In some cases, fatigue may become a chronic problem, lasting beyond the treatment period. More serious side effects, some of which are life-threatening, depend on the type of agent used.

Blood cancers are among the few cancers for which the U.S. Food and Drug Administration has approved the use of biological therapy for treatment. One such therapy is rituximab, an antibody against a lymphocyte marker. It is used against relapsed or refractory low-grade lymphoma. Biologic therapy is often experimental, and you may need to seek out a qualified hospital to administer it if that is the route you and your doctor choose.

Last Updated: 9/24/2002
The Johns Hopkins University 1996-2003.  All rights reserved.  This information is not intended to provide advice on personal medical matters, nor is it intended to be a substitute for consultation.