The prostate, an organ in the male reproductive system, is responsible for secreting fluids that make up portions of the semen, keeping urine out of the semen and enhancing sexual pleasure. The American Cancer Society reports that cancer of the prostate is the second most common cancer in men after skin cancer. There are several types of drug therapies available to treat prostate cancer.
Hormone Therapy
Prostate cancer cells require male hormones called androgens in order to grow. Therefore medications that reduce the level of these hormones, or interfere with their ability to interact with the cancer cells, can help to shrink a prostate cancer tumor and slow its growth rate. They will not, however, cure the cancer.
Medications known as luteinizing hormone-releasing hormone agonists, or LHRH agonists, inhibit the testicles which produce the majority of the androgen, testosterone. These medications block the signals that trigger testosterone production. Administering LHRH agonists is often referred to as "chemical castration" because the medications reduce androgen levels as effectively as surgical castration. One disadvantage of this type of medication is that, once administered, the testosterone levels actually spike, fueling the growth of the tumor. Examples of LHRH agonists include leuprolide, goserelin, triptorelin and histrelin.
Luteinizing hormone-releasing hormone antagonists, such as degarelix, are newer medications that work in a similar way to the LHRH agonists. The advantage to the LHRH antagonists is that they reduce the testosterone level quickly without first spiking them.
Another type of medication known as anti-androgen therapy prevents testosterone from reaching the tumor cells. These medications, including flutamide, bicalutamide and nilutamide, are usually administered along with an LHRH agonist or antagonist.
Chemotherapy
Chemotherapy drugs are medications that target rapidly growing cells, which makes it effective against many types of cancer. These medications are often administered to patients whose prostate cancer has spread to other parts of the body or who have not responded to hormone therapy. Although chemotherapy drugs can effectively kill cancer cells, they can also affect normal cells resulting in a variety of side effects.
Immunotherapy
Immunotherapy medications are drugs that trigger the body's immune system to fight off the cancer. Monoclonal antibody medications, such as rituximab, are a specific type of immunotherapy drugs that target and kill cancer cells by triggering antibodies to kill cells. New immunotherapy medications are currently being studied and are awaiting approval by the U.S. Food and Drug Administration, according to a 2007 article published in "Reviews in Urology."
