Cancer - Treatment
Cancer treatment has two goals. First, as much of the original tumor as possible should be removed. Second, the tumor should be prevented from recurring or spreading to other parts of the body. One decision that often has to be made concerns the side effects of cancer treatments. Most cancer treatments are designed to kill cancer cells, but those treatments can also kill healthy cells. A patient undergoing cancer treatment can, therefore, become very ill from the treatments themselves.
In such cases, patients sometimes choose not to make use of treatments that try to cure the cancer. Instead, they are given other kinds of treatments designed to relieve their symptoms and make them more comfortable.
Many forms of cancer treatment are available. The form used with any one patient depends on many factors, including the patient's age, sex, general health, personal preferences, type and location of the cancer, and extent to which it has already metastasized (spread to other parts of the body, pronounced muh-TASS-tuh-sized). The major types of cancer treatment are surgery, radiation, chemotherapy, immunotherapy, hormone therapy, and bone marrow transplantation.
Surgery involves the removal of a visible tumor and is the most common form of cancer treatment. Surgery is most effective when the tumor is small and confined to one area of the body. Surgery can be used for many purposes:
- Treatment. When a tumor is removed surgically, a small amount of surrounding tissue is also removed. This ensures that no cancer cells are left in the area. Since cancer cells are often spread by means of the lymphatic system, nearby lymph nodes may also be removed.
- Cytoreduction. In some cases, it may be impossible to completely remove all the cancer cells by surgery. Cytoreduction ("cell reduction"; pronounced SITE-o-ree-duk-shun) involves the removal of as much cancerous tissue as possible. Any remaining abnormal tissue is then treated with radiation, chemotherapy, or both.
- Palliation. Tumors are sometimes so large that they cannot be removed completely by surgery. In such cases, palliative surgery is used to take out as much of the tumor as possible. This procedure often helps to relieve the symptoms of cancer even if it does not cure the disease itself. For example, a large tumor in the abdomen may press on and block a part of the intestine. The patient may be unable to digest food and feel constant pain and discomfort. Even if the whole tumor cannot be removed, some part of it can probably be taken out. The digestive system can then function normally again.
- Prevention. Preventive surgery may be used even if no tumors exist. The presence of abnormal tissue may suggest that tumors could eventually form. To avoid that possibility, the tissue can be removed. Preventive surgery is often used, for example, to prevent ulcerative colitis (see ulcerative colitis entry). About 40 percent of the people with this form of cancer die from the disease. People with the disease may choose to have their colons removed rather than risk dying of ulcerative colitis.
- Diagnosis. Whenever possible, biopsies are conducted with a needle. The needle is used to take out a small piece of tissue for study. Sometimes, a needle biopsy cannot be used. In those cases, surgery may be necessary to get the tissue needed for study.
Radiation kills cancer cells. It can be used alone when a tumor cannot be removed surgically. More often, radiation is used in combination with surgery and chemotherapy. Radiation can be performed from either the outside or the inside of the body. An example of outside radiation is the use of X rays to treat a tumor. Inside radiation can be carried out by inserting pellets or liquids in a patient's body. Radiation given off by the pellets or liquid attacks and kills cancer cells.
Chemotherapy is the use of chemicals or drugs to kill cancer cells. It is used to destroy cells that have spread from the original tumor and are circulating in the body. The drugs used for chemotherapy can be given orally (by mouth) or by injection. They are used alone or in combination with surgery and radiation.
Chemotherapy is sometimes used before surgery or radiation because drugs are often able to kill cancer cells and reduce the size of a tumor. Surgery and radiation are likely to be more effective when used on smaller tumors. More often, chemotherapy is used after surgery or radiation treatments. In such cases, drugs may be able to destroy cancer cells remaining in the body after the initial treatment.
Immunotherapy is a relatively new form of cancer treatment. Its goal is to kill cancer cells by using chemicals that occur naturally in the body. Chemicals known as interferons are an example. Interferon can be given to a cancer patient to stimulate his or her own immune system to fight cancer more effectively.
Research is also being done to develop a cancer vaccine. A cancer vaccine is different from other kinds of vaccines. It is not being designed to prevent cancer. Instead, it will be given to patients who already have the disease. It is intended to help the patient's immune system fight cancer cells.
Some forms of cancer grow faster when certain hormones are present. Examples of such cancers include cancer of the breast, prostate, and uterus. Hormone therapy involves the use of drugs that reduce the amount of hormones produced and their ability to cause changes in the body. These drugs can slow down the rate at which hormone-related cancers develop, extending the patient's life by months or years.
Bone Marrow Transplantation
Bone marrow is tissue found in the center of bones. It produces cells that develop into new blood cells. Radiation and chemotherapy often destroy bone marrow and the patient's body is no longer able to produce the amount of blood it needs to stay healthy.
Bone marrow transplantation involves the removal of some bone marrow from one person so that it can be given to another person. For the procedure to be successful, the two people must be closely related or have similar blood characteristics. Bone marrow transplantation can be important with patients who require very aggressive (serious) forms of treatment that are likely to destroy their own bone marrow.
Many alternative forms of cancer treatment are available, however, patients should always seek the advice of trained health practitioners before trying alternative treatments. Treatment methods from other cultures can sometimes be effective in treating the symptoms of cancer or the side effects of radiation or chemotherapy. Two examples are acupuncture (a Chinese therapy technique where fine needles puncture the body) and Chinese herbal medicines. Body massage can help to ease muscle tension and reduce side effects such as nausea and vomiting.
Experts now believe that certain kinds of food, such as fruits, vegetables, and grains, can help protect against various forms of cancer. For example, a diet rich in fiber, which includes fruits and vegetables, seems to reduce the risk of colon cancer. Exercise and a diet low in fat can help control weight and reduce the risk of breast and colon cancers.
Scientists are not sure what is in foods that prevents cancer. Vitamins A, C, and E and the compound known as beta-carotene are likely prospects. So are two groups of compounds known as the isothiocyanates (pronounced I-so-THI-o-si-uh-nates) and the dithiolthiones (pronounced di-THI-ul-THI-ownz). These compounds are found in broccoli, cauliflower, cabbage, and carrots.
Some drugs used for cancer treatment may also help prevent the disease. Tamoxifen (pronounced tuh-MOK-sih-fen, trade name Nolvadex) is an example. Research is now being conducted to determine its effectiveness in preventing breast cancer. Compounds known as retinoids, obtained from vitamin A, are also being tested for use against head and neck cancers. The mineral selenium may also hold some promise for the prevention of some forms of cancer.