High-dose chemotherapy and/or radiation therapy, followed by a procedure called an allogeneic stem cell transplantation (SCT), is an option for a cure for some persons with cancer. However, there are a number of risks that are associated with the transplant procedure, 1 of which is the development of lymphoma, a cancer of the lymphocyte cells and lymphoid system. Researchers in Texas now say that a biologic therapy, called Rituxan™, may be an effective treatment for lymphoma that develops after an SCT.
Lymphoma is a cancer that is characterized by the presence of cancerous lymphocyte cells (a type of white blood cell) in the lymph system, which includes the blood vessels, lymph nodes, and organs such as the spleen, thymus, and tonsils. Lymphoma can start almost anywhere in the lymph system, and can then spread to other parts of the body. There are 2 main types of lymphoma, Hodgkin’s disease and non-Hodgkin’s lymphoma. Some persons who have cancer receive an allogeneic stem cell transplantation, an infusion of donated young bloods cells called
stem cells, to replace the patient’s damaged stem cells after high-dose chemotherapy, in an effort to cure the cancer. One of the complications of an allogeneic SCT is that the patient’s immune system is weakened after the procedure, and viruses such as the Epstein-Barr virus (EBV) may be introduced or activated. The EBV is a common virus, responsible for mononucleosis (mono) infections throughout the world. In persons who have just undergone an SCT and have a weakened immune system, the EBV is a risk factor for the development of lymphoma. EBV alone does not cause the lymphoma. However, together with other risk factors such as receiving transplant cells that are depleted of T cells, receiving transplant cells from a mismatched donor, and being treated for another transplant complication called graft-versus-host disease, EBV is associated with the development of lymphoma. EBV-associated lymphomas can include both Hodgkin’s disease and non-Hodgkin’s lymphomas.
Treatment for EBV-associated lymphoma often entails the infusion of lymphocytes from the donor into the patient. This strategy has been found to improve immune function and thus control the EBV and eradicate lymphoma cells. Unfortunately, after the lymphocyte infusion, some persons will develop
graft-versus-host disease, a serious condition that occurs when the patient’s body has difficulty accepting the donor blood cells; therefore, alternative treatments are needed. Rituxan™ is a monoclonal antibody, a type of biologic therapy (or immunotherapy) used to help the immune system fight cancer cells. This relatively new agent binds to a protein, called the CD20 antigen, present on the surface of mature B cells and B-cell cancerous tumors that are present in many types of lymphoma. This process in turn causes the body’s immune system to attack the B cells, including those that are cancerous.
Researchers in Texas treated 3 persons who developed EBV-associated lymphoma after undergoing an SCT procedure. Each patient received a single dose of Rituxan. All 3 patients responded to the treatment and, after several months, have not had a recurrence (return) of the lymphoma.
These findings suggest that the use of Rituxan to treat EBV-associated lymphoma may be promising; however, further study is needed to determine the long-term effects of this therapy. Persons who have an EBV-related lymphoma may wish to talk with their doctor about the risks and benefits of the Rituxan regimen, or of participating in a clinical trial in which other new treatments are being studied. Sources of information on ongoing clinical trials that can be discussed with a doctor include a comprehensive, easy-to-use service provided by the National Cancer Institute (cancer.gov) and the Clinical Trials section and service offered by Cancer Consultants.com (www.411cancer.com). (Blood, Vol 95, No 4, pp 1502-1505, 2000)
Copyright © 2018 CancerConnect. All Rights Reserved.