Cancer is the result of cells developing a mutation in their DNA, which causes them to develop changes in appearance and behavior. Cancer cells grow abnormally quick and do not respond when the body signals them to stop dividing. Although different cancers require different treatments, most cancers are treated with a combination of surgery, radiation, chemotherapy and/or targeted therapies.
Surgery
One of the simplest and most common methods of treating cancer is through surgery. Surgical treatment of cancer involves cutting out the malignant tumor or tumors. Typically the surgeon will also try to cut out a small amount of healthy tissue around the tumor to make sure that as much cancerous material as possible has been removed. The removed tissue will be sent to a pathologist who will examine it under a microscope to see if the margins of the tissue are filled with normal cells. If so, it means that the surgeon likely cut out all of the tumor. Surgical removal of a tumor is usually followed up with other cancer treatments to obliterate any cancer that was not visible to the surgeon, or that was unable to be removed.
Radiation
Radiation can also be used to treat cancer. Radiation uses high energy X-ray beams which are able to penetrate cells and damage their DNA, causing them to die. These X-rays cause the most damage to cells that are rapidly dividing. Because cancer cells divide so quickly, they receive the brunt of the damage. Radiation treatment can either administered using a machine that produces the X-rays from outside the body (external beam radiation therapy) or by implanting a small piece of radioactive material near the tumor (brachytherapy).
Chemotherapy
Chemotherapy is similar to radiation treatments in that it works by killing cells that are dividing rapidly. However, chemotherapy also poisons these rapidly dividing cells. Chemotherapy can either be given orally (usually in the form of a pill) or via injection (sometimes directly into the veins). Typically patients will receive chemotherapy treatments for a period of time (known as a "chemo cycle"), with brief recovery periods between treatments.
Targeted Treatments
Targeted treatments cannot be used for all kinds of cancer, but when they are an option, they can be extremely effective. According to the National Cancer Institute, targeted therapies are often more effective than radiation and chemotherapy. Targeted treatments are developed specifically to attack the abnormal cells. They are typically either antibodies developed to attack specific parts of the cancer cell or small molecules that cause the cancer cells to stop growing. Examples of targeted therapies include tamoxifen (which is used for breast cancer) and Gleevec (which is used for some kinds of leukemia and gastrointestinal tumors).
