Prostate cancer begins in the prostate gland, a small, walnut-sized gland which is part of a man’s reproductive system. It wraps around the urethra, a tube which carries urine out of the body. The third most common cause of cancer death in men of all ages, prostate cancer is the most common cause of death in men over age 75 and is rare in men younger than 40. Men at higher risk for prostate cancer include African-Americans, men over 60 and men whose brother or father have had prostate cancer. Others at risk include men exposed to agent orange, men who abuse alcohol, farmers, men whose diets are high in animal fat, tire plant workers, painters and men who have been exposed to cadmium. Many of these men will use prostate cancer drugs to manage their disease.
Standard treatments for prostate cancer include watchful waiting, usually used in older men and early-stage disease; surgery, used when patients are in good health to remove the tumor; radiation therapy, which uses internal or external radiation to kill cancer cells; and drug therapy, consisting of hormone therapy, chemotherapy or immunotherapy to stop cancer cell growth.
Hormone Therapy Drugs
Prostate cancer drugs include hormone therapy, which decreases the effect of testosterone on prostate cancer. Testosterone is the main male hormone which the cancer needs to grow. Hormone treatments can prevent further growth and spread of the cancer. It is primarily used to relieve symptoms in men whose cancer has spread.
The primary type of hormone therapy is called a luteinizing hormone-releasing hormones (LH-RH) agonist. These drugs keep the body from making testosterone and are given by injection, usually each three to six months. This category includes the drugs leuprolide, goserelin, nafarelin, triptorelin, histrelin, buserelin and degarelix.
Other hormone medications are called androgen-blocking drugs and they are often given along with the LH-RH agonist drugs. They include flutamide, bicalutamide and nilutamide.
Drugs that prevent the adrenal glands from making androgens are ketoconazole and aminoglutethimide. Rarely used today because of side effects are the female hormones, estrogens, which can prevent the testicles from producing testosterone.
Drugs used in prostate cancer treatment also include chemotherapy drugs, which stop the growth of cancer cells by killing them or keeping them from dividing. When chemotherapy is taken orally or injected into a vein, it has a systemic effect. When it is placed directly into the cerebrospinal fluid, an organ or body cavity, it is called regional chemotherapy. The way it is given usually depends on the type and stage of the cancer being treated. Chemotherapy usually is called into play when patients experience either hormone refractory cancer or prostate cancer bone metastasis. Doctors may use small, frequent doses of pills or venous access devices for frequent, low dose injections.
Doxorubicin is a chemotherapy agent that works by binding to the DNA of a cell and inhibits the production of protein. It is given intravenously and can cause serious tissue damage if it escapes from the vein. Estramustine phosphate is an alkylating agent taken by capsule and cannot be taken with dairy products which reduce its effectiveness. Etoposide can be taken orally or by infusion, but patients need to talk with their physicians about what foods and behaviors they should avoid while taking. Belonging to the group called antineoplastics is mitoxantrone, given by injection and sometimes taken with corticosteroids, such as prednisone. Another antineoplastic is vinblastine. Antineoplastics are also known as anti-tumor antibiotics. Taxanes are effective by locking the microtubules that make up the cells cytoskeleton into place, causing cell death while it tries to divide. Taxanes are paclitaxel and docetaxel.
Since chemotherapy drugs can cause serious side effects, patients should be diligent about pursuing information from their doctors about which drugs will benefit them the most.
In 2010 the Food and Drug Administration approved the drug, Provenge, as a “vaccine” for prostate cancer. It is not a preventive vaccine but a therapeutic one that trains the body’s own immune system to fight the disease. In clinical trials it extended the lives of patients about four months compared with placebo.
Prostate Cancer Treatment Guide - https://www.prostate-cancer.com/chemotherapy/treatments/chemotherapy-treatments.html
The New York Times - https://www.nytimes.com/2010/04/30/health/30drug.html
National Cancer Institute - https://www.cancer.gov/cancertopics/pdq/treatment/prostate/patient/page4
Medline Plus - https://www.nlm.nih.gov/medlineplus/ency/article/000380.htm