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Usually one of two systems are used to stage CLL. One of these is the Binet system and the other the Rai system. According to the Rai system, patients at low risk have no enlargement of lymph nodes, spleen or liver. The occurrence of these marks entry into the intermediate stage, according to Rai. High risk patients have, in addition, anemia and a significant decrease in the number of blood platelets in their blood. Blood platelets help blood to clot. According to the Binet system, a patient's stage depends upon how much hemoglobin (part of red blood cells that carry oxygen) and how many platelets are in the blood, as well as how many other areas the disease has affected. According to both systems, patients at low risk usually survive more than ten years. Patients at intermediate risk usually survive about six years. Patients at high risk usually survive about 2 years. Other factors with important implications for prognosis include the pattern at which bone marrow is being affected by the CLL and the amount of time it takes for the number of lymphocytes to double.
Because the long-term prognosis for many patients with CLL is excellent, many patients receive no treatment at all at first. Many patients go for years before developing aggressive disease that requires treatment. Treatment for early stage CLL should be started only when one of the following conditions appears:
Therapy for CLL usually starts with chemotherapy. Depending on the stage of the disease, single or multiple drugs may be given. Drugs commonly prescribed include fludarabine, cladribine, chlorambucil and cyclophosphamide. Studies have also provided evidence that a combination of fludarabine and cyclophosphamide is effective. However, this combination has not yet been evaluated over periods of ten years or more. Another combination now being studied involves fludarabine and mitoxantrone (Novantrone). Yet another involves fludarabine and anthracyclines. Low-dose radiation therapy may be given to the whole body, or it may be used to alleviate the symptoms and discomfort due to an enlarged spleen and lymph nodes. The spleen may be removed in a procedure called a splenectomy.
Bone marrow transplantation (BMT) has produced some positive outcomes in patients with CLL, although it has not been the subject of sufficient systematic study to permit doctors to know how effective it is. In BMT, the patient's diseased bone marrow is replaced with healthy marrow. There are two ways of performing a bone marrow transplant. In an allogeneic bone marrow transplant, healthy marrow is taken from another person (donor) whose tissue is either the same or very closely resembles the patient's tissues. The donor may be a twin, a sibling, or a person who is not related at all. First, the patient's bone marrow is destroyed with very high doses of chemotherapy and radiation therapy. To replace the destroyed marrow, healthy marrow from the donor is given to the patient through a needle in the vein.
In the second type of bone marrow transplant, called an autologous bone marrow transplant, some of the patient's own marrow is taken out and treated with a combination of anticancer drugs to kill all the abnormal cells. This marrow is then frozen to save it. The marrow remaining in the patient's body is then destroyed with high-dose chemotherapy and radiation therapy. Following that, the patient's own frozen marrow is thawed and given back to the patient through a needle in the vein. The use of this mode of bone marrow transplant for the treatment of CLL is currently being investigated in clinical trials.
Allogeneic BMT has been successfully used with younger patients with CLL who have not responded positively to chemotherapy. Autologous BMT has produced some positive results in older CLL patients. However, BMT is generally not considered an option in treating most patients with CLL because they are too old to be considered good candidates for the procedure.
Other CLL therapies that are being investigated include monoclonal antibody-targeted therapy and inter-ferons. Monoclonal antibodies (MoAbs) are laboratory-manufactured chemicals that closely resemble parts of the body's natural immune system. Studies of MoAbs-targeted therapies have shown some positive results in CLL, although definitive studies have not been performed at the
Radiation therapy is very effective for approximately one in three of those CLL patients for whom it is considered appropriate.
Because leukemia cells can spread to all the organs via the blood stream and the lymph vessels, surgery is not considered an option for treating leukemias.
During therapy for CLL, complications frequently appear. Many patients develop infectious illnesses. Sometimes, two or more infectious diseases attack a patient at the same time. These infections should be treated with great care. Most people whose death has been directly attributed to CLL have actually died from bacterial infections. The patient should be involved in identifying symptoms of infection and reporting these to the doctor without delay. Doing so may save the patient's life.
Many patients develop anemia, which is treated with the drug prednisone. Patients who do not respond to prednisone therapy may have their spleen removed and may receive therapy with immunoglobulin, a component of the blood.
Between three and ten out of every hundred patients with CLL experiences transformation of the disease into large-cell lymphoma (LCL). When this happens it is called Richter's transformation. Its occurrence is often marked by fever, weight loss, and night sweats. Treatments for LCL are being studied, although outcomes have not been very good. Very infrequently, CLL may transform into another disease, called prolymphocytic leukemia. Attempts to develop adequate therapies for this disease are ongoing.
For many CLL patients, the prognosis is excellent. Using the Binet and Rai staging systems, patients at low risk usually survive more than ten years. Patients at intermediate risk usually survive about six years. Patients at high risk usually survive about two years. The average patient survives approximately nine years following diagnosis. Factors with important implications for prognosis that are not included in the Binet or Rai systems are the pattern at which bone marrow is being affected by the CLL and the amount of time it takes for the number of lymphocytes in the blood to double. It is uncertain whether BMT may prolong the lifespan of CLL patients. Many of the chemotherapy agents used to treat disease do effectively control the leukemia and its effects but, as yet, the more established chemotherapy agents have not been shown to increase the life span of patients.
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Author Info: Lata Cherath Ph.D., Bob Kirsch, The Gale Group Inc., Gale, Detroit, Gale Encyclopedia of Cancer, 2002 |