Cancer can be treated by surgery, chemotherapy, radiation therapy or other methods. The choice of therapy depends upon the location and grade of the tumor and the stage of the disease.
If the tumor is localized, surgery is often the preferred treatment. Example procedures include prostatectomy for prostate cancer and mastectomy for breast cancer. The goal of the surgery can be either the removal of only the tumor, or the entire organ.
Since a single cancer cell can grow into a sizeable tumor, removing only the tumor leads to a greater chance of recurrence. A margin of healthy tissue is often resected to allow for small amounts of residual tumor cells.
In addition to removal of the primary tumor, surgery is often necessary for staging, e.g. determining the extent of the disease and whether there has been metastasis to regional lymph nodes. Staging determines the prognosis and the need for adjuvant therapy.
Chemotherapy is the treatment of cancer with drugs that can destroy cancer cells. These drugs often are called “anticancer” drugs. Normal cells grow and die in a controlled way. When cancer occurs, cells in the body that are not normal keep dividing and forming more cells without control.
Anticancer drugs destroy cancer cells by stopping them from growing or multiplying. Healthy cells can also be harmed, especially those that divide quickly. Harm to healthy cells is what causes side effects.
These cells usually repair themselves after chemotherapy. Because some drugs work better together than alone, two or more drugs are often given at the same time. This is called combination chemotherapy.
Radiation therapy (also called radiotherapy, x-ray therapy, or irradiation) is the use of a certain type of energy (called ionizing radiation) to kill cancer cells and shrink tumors. Radiation therapy injures or destroys cells in the area being treated (the “target tissue”) by damaging their genetic material, making it impossible for these cells to continue to grow and divide.
Although radiation damages both cancer cells and normal cells, most normal cells can recover from the effects of radiation and function properly. The goal of radiation therapy is to damage as many cancer cells as possible, while limiting harm to nearby healthy tissue.
Radiation therapy may be used to treat almost every type of solid tumor, including cancers of the brain, breast, cervix, larynx, lung, pancreas, prostate, skin, spine, stomach, uterus, or soft tissue sarcomas.
Radiation can also be used to treat leukemia and lymphoma (cancers of the blood-forming cells and lymphatic system, respectively). Radiation dose to each site depends on a number of factors, including the type of cancer and whether there are tissues and organs nearby that may be damaged by radiation.
Cancer Clinical trials
Clinical trials, also called experimental cancer treatment or research studies, test new treatments in people with cancer. The goal of this research is to find better ways to treat cancer and help cancer patients. Clinical trials test many types of treatment such as new drugs, new approaches to surgery or radiation therapy, new combinations of treatments, or new methods such as gene therapy.
A clinical trial is one of the final stages of a long and careful cancer research process. The search for new treatments begins in the laboratory, where scientists first develop and test new ideas.
If an approach seems promising, the next step may be testing a treatment in animals to see how it affects cancer in a living being and whether it has harmful effects. Of course, treatments that work well in the lab or in animals do not always work well in people. Studies are done with cancer patients to find out whether promising treatments are safe and effective.
The patients who take part may be helped personally by the treatment(s) they receive. They get up-to-date care from cancer experts, and they receive either a new treatment being tested or the best available standard treatment for their cancer. Of course, there is no guarantee that a new treatment being tested or a standard treatment will produce good results.
New treatments also may have unknown risks. But if a new treatment proves effective or more effective than standard treatment, study patients who receive it may be among the first to benefit. Some patients receive only standard treatment and benefit from it.
Complementary and Alternative Medicine
Complementary and alternative medicine (CAM) is a group of diverse medical and health care systems, practices, and products that are not presently considered to be part of conventional medicine.
It is important that the same scientific evaluation that is used to assess conventional approaches can be used to evaluate CAM therapies.
In the United States, current trials are underway to test the following:
- acupuncture to reduce the symptoms of advanced colorectal cancer,
- combination chemotherapy plus radiation therapy with or without shark cartilage in the treatment of patients who have non-small cell lung cancer that cannot be removed by surgery,
- hyperbaric oxygen therapy with laryngectomy patients (people who have had an operation to remove all or part of the larynx (voice box)),
- massage therapy for cancer-related fatigue,
- chemotherapy compared with pancreatic enzyme therapy plus specialized diet for the treatment of pancreatic cancer, and mistletoe extract and chemotherapy for the treatment of solid tumors.