Treating cancer is one of the most complex aspects of medical care. It involves a team that encompasses many types of doctors working together (for example, primary care doctors, gynecologists or other specialists, medical oncologists, radiation oncologists, surgeons, and pathologists) and many other types of health care practitioners (for example, nurses, radiation therapists, physiotherapists, social workers, and pharmacists).
Treatment decisions take into account many factors, including the likelihood of cure or of prolonging life when cure is not possible, the effect of treatment on symptoms, the side effects of treatment, and the person's wishes. People undergoing cancer treatment hope for the best outcome and the longest survival with the highest quality of life. However, people must understand the risks involved with treatment. They should discuss their wishes regarding medical care with all of their doctors and should participate in decisions about treatment (see Advance Directives).
When the diagnosis of cancer is first made, the main goals of treatment are to remove the cancer if possible (through a single treatment or through a combination of surgery, radiation therapy, and chemotherapy). Chemotherapy is usually the only way to treat any cancer cells that have spread (metastasized) beyond the original (primary) site. Using combinations of chemotherapy drugs may help eliminate the original cancer and, at the same time, eliminate cancer cells elsewhere in the body, even when there is no sign of those cells.
Even when a cure is impossible, symptoms resulting from the cancer can often be relieved with treatment that improves the quality of life (palliative therapy). For example, if a tumor cannot be removed surgically, radiation to the tumor may shrink it, temporarily reducing pain and symptoms in the immediate vicinity of the tumor (local symptoms).
Because treatments are complex, specific approaches to care, called treatment protocols, have been developed to ensure that people receive the safest and most effective care. Treatment protocols ensure that people receive a standard approach derived from careful scientific experiments. Protocols are typically developed and refined through clinical trials. A clinical trial allows doctors to compare new drugs and treatment combinations with standard treatments to determine whether new treatments are more effective. Often, people with cancer are offered the opportunity to participate in such a trial, but not all people with cancer are eligible (see What Participants Need to Know About Clinical Trials).