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Cancer Treatment |
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Cancer treatment involves medical procedures to destroy, modify, control, or remove primary, regional, or metastatic cancer tissue. The goals of cancer treatment include eradicating known tumors entirely, preventing the recurrence or spread of the primary cancer, and relieving symptoms if all reasonable curative approaches have been exhausted. Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping the cells from dividing. When chemotherapy is taken by mouth or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy). When chemotherapy is placed directly into the spinal column, an organ, or a body cavity such as the abdomen, the drugs mainly affect cancer cells in those areas (regional chemotherapy). The way the chemotherapy is given depends on the subtype of the cancer being treated and whether it has spread to the brain and spinal cord. Combination chemotherapy refers to treatment using more than one anticancer drug. Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells. There are two types of radiation therapy. External radiation therapy uses a machine outside the body to send radiation toward the cancer. Internal radiation therapy uses a radioactive substance sealed in needles, seeds, wires, or catheters that are placed directly into or near the cancer. The way the radiation therapy is given depends on the type and stage of the cancer being treated. The chemotherapy and radiation that kill malignant cells also kill healthy marrow and its resident blood stem cells, which are the source of all immune cells. In order to giving high doses of chemotherapy or radiation therapy, stem cell transplant may be used. In this method, stem cells are removed from the blood or bone marrow of the patient or a donor and are frozen and stored. After the chemotherapy or radiation therapy is completed, the stored stem cells are thawed and given back to the patient through an infusion. These reinfused stem cells grow into (and restore) the body's blood cells. Hematopoietic or blood stem cell transplants are also called bone marrow transplants or peripheral blood stem cell transplants, depending upon the location of stem cell collection. Biologic therapy is a treatment that uses the patient's immune system to fight cancer. Substances made by the body or made in a laboratory are used to boost, direct, or restore the body's natural defenses against cancer. This type of cancer treatment is also called immunotherapy. One type of biological therapy is monoclonal antibody therapy, a cancer treatment that uses antibodies made in the laboratory from a single type of immune system cell. These antibodies can identify substances on cancer cells or normal substances that may help cancer cells grow. The antibodies attach to the substances and kill the cancer cells, block their growth, or keep them from spreading. Monoclonal antibodies are given by infusion. They may be used alone or to carry drugs, toxins, or radioactive material directly to cancer cells. Hormone therapy is a cancer treatment that removes hormones or blocks their action and stops cancer cells from growing. Hormones are substances produced by glands in the body and circulated in the bloodstream. The presence of some hormones can cause certain cancers to grow. If tests show that the cancer cells have places (receptors) where hormones can attach, drugs, surgery, or radiation therapy are used to reduce the production of hormones or block them from working. An example of hormone therapy is the use of tamoxifen for breast cancer. Tamoxifen acts by attaching to the cell surface estrogen receptor without initiating the intracellular processes which leads to proliferation. Its presence at the receptor site blocks the attachment of estrogen and thus interferes with their actions on breast cells and breast cancer cells.
Targeted cancer therapy uses drugs to stop the growth of cancer cells by interfering with specific molecules involved in cell division or apoptosis (death). By focusing on molecular and cellular changes that are specific to cancer, targeted cancer therapy may be more selective than traditional chemotherapy and thus less harmful to normal cells. Examples of targeted cancer therapy include the following drugs:
Reference: National Cancer Institute, USA.
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