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Growth Factor Therapy Helps Cancer Patients | |
| By DR. ALEC S. GOLDENBERG New York University Medical Center For AP Special Features Genetic engineering has moved out of the laboratory and into the cancer clinic, where it is helping save the lives of patients with several kinds of malignancies. New techniques using genetically engineered molecules allow physicians to give patients intensive doses of anti-cancer drugs that are more effective at killing cancer cells more safely. Intensive chemotherapy normally kills some normal cells-notably the immune system cells that grow in the bone marrow and fight infection. Intensive doses of most chemotherapeutic agents result in significantly lower counts of white blood cells, which are the mainstay of the body's defenses against infection. Infection can result from overgrowth of bacteria that live in the body and are normally kept under control, or from infectious agents found in hospitals that can enter the body when openings are made in the skin - for example, to introduce catheters. Infection thus, is one of the most significant problems in cancer patients who get aggressive chemotherapy. Antibiotic therapy is often not enough to fight these infections. Physicians are therefore giving patients growth factors that stimulate the production of white blood cells in the bone marrow. The two most commonly used growth factors are Granulocyte-Colony Stimulating Factor (GCSF, sold as Neupogen) and Granulocyte-Monocyte Stimulating Factor (GMCSF, sold as Leukine). Use of these growth factors allows doctors to give higher doses of chemotherapy. Those higher doses can cure some people who would not be cured by standard therapy, such as patients with leukemia or lymphoma. But at those even higher doses, the anti-cancer drugs can literally wipe out the cells of the bone marrow, leaving the body defenseless. Growth factors alone aren't effective when significant numbers of bone marrow cells are killed. To restore the defenses, patients can additionally be given transplants of stem cells, the basic cells that give birth to all the variety of cells in the bone marrow. These stem cells are usually collected from patients' own peripheral blood, stored, and later reinfused after chemotherapy treatment. Sometimes stem cells from other donors are used. The stem cells allow the bone marrow to recover much more quickly than with growth factor alone. Both techniques make high-dose chemotherapy safer. There is a constant effort to reduce the danger of infection for cancer patients. Some medical centers now are doing studies to see whether the combination of growth factors and antibiotics is more effective than growth factors alone. The results of the studies are not yet conclusive. --- Dr. Alec S. Goldenberg is an Assistant Professor in Clinical Medicine at New York University School of Medicine. Copyright 1996 Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed. | |