Hormone therapy - uses various hormones to stop cancer cells from growing. It is used for prostate cancer that has spread to distant parts of the body. Chemotherapy is the use of drugs to kill cancer cells. The drugs can be given by pill, or may be put into the body by inserting a needle into a vein or muscle. Most commonly, chemotherapy is advised if the cancer does not respond to hormone therapy.
Biological therapy tries to get the body to fight the cancer.
It uses materials made by the body or made in a laboratory to help the body's natural defenses. Although some trials of this kind of treatment are showing promise, it isn't yet clear if this therapy is effective or not. For example, if a very elderly man has a very slow-growing form of cancer, it may not make sense to treat it. The cancer is not likely to cause any problems. The doctor carefully watches the progress of the cancer through frequent follow-up exams.