Cancer is a devastating disorder that is the leading cause of death worldwide, accounting for 7.4 million deaths in 2004, according to the World Health Organization. Cancer develops from normal cells within the body that acquire genetic mutations, causing them to divide more quickly and indefinitely and evade cell death. Over time, the mutated cells form a tumor that can then migrate throughout the body and form secondary tumors in a process called metastasis. Cancer can affect virtually any tissue of the body and a number of methods can treat it.
Surgery
Surgical removal of the tumor, as well as any affected tissue, is a common course of treatment for cancer. Surgery is helpful in treating solid tumors, as the tumor can be cut out and the neighboring tissue preserved. This is especially true if the tumor has well-defined borders that do not invade into the neighboring tissue. In some cases of non-solid tumors, such as some blood cancers, the bone marrow cells that give rise to cancer cells may be removed and replaced to treat the cancer.
Surgery for cancer may involve removal of the entire tumor, removal of part of the tumor in preparation for other treatments, or surgery as part of palliative therapy to relieve the symptoms of advanced cancer, according to the American Cancer Society. If the cancer has metastasized before the surgery, surgical removal of the original tumor will not prevent development of secondary tumors, and the cancer will likely recur.
Immunotherapy
In many diseases, the immune system recognizes a harmful foreign object within the body, such as a bacterium or virus, and destroys the object to prevent disease. In cancer, the cells responsible for the disease are the patient's own cells, so the immune system does not attack and destroy them to prevent cancer development. The goal of immunotherapy is to use drugs to identify the cancer cells as foreign, so the body's immune system destroys the cancer cell to treat the tumor.
Immunotherapy drugs are molecules called antibodies, which are proteins designed to bind to specific factors on cancer cells. Immunotherapy antibodies bind specifically to factors found on cancer cells, then the immune system recognizes the antibody as foreign and the immune system destroys the antibody and the cell it is attached to. A number of immunotherapy drugs have been developed, such as the therapeutic Herceptin, which is used to treat certain forms of breast cancer.
Radiotherapy
Radiotherapy is the use of radiation to treat cancer. Radiation is extremely harmful to cells--it leads to massive damage to the cells' genetic material, which prevents the cell from making the proteins it needs to live and grow. Radiation therapy works by administering a high dose of radiation into the tumor, causing tumor cell death and treating the cancer.
The use of radiation therapy can have a number of side effects. This is because radiation affects normal cells as well as cancer cells. The normal tissues surrounding the tumor also receive a dose of radiation, which damages the tissue. Radiotherapy for cancers close to the reproductive organs can often lead to sterility. Additionally, radiotherapy can increase the risk of developing other forms of cancer in the future, due to genetic mutations neighboring cells acquire as a result of the treatment. Radiotherapy should be used if the benefits far outweigh the risks of treatment.
