Hormone therapy for prostate cancer (androgen deprivation therapy, or ADT)
Hormone therapy for prostate cancer is also known as androgen deprivation therapy (ADT). Prostate cancer cannot grow or survive without androgens, which include testosterone and other male hormones. Hormone therapy decreases the amount of androgens in a man's body. Reducing androgens can slow the growth of the cancer and even shrink the tumor.
Prior to surgery to remove the prostate (prostatectomy), hormone therapy may be used on its own. It may also be used along with radiation treatment when there is a high risk of the cancer returning. Or hormone therapy may be used after surgery or radiation if any cancer remains. Hormone therapy may also help men who have cancer that has spread and who cannot have surgery or radiation.
Taking medicines, such as LH-RH and GnRH agonists and antiandrogens, is one way to reduce androgens. Another way, used much less often, is surgery to remove the testicles, also known as an orchiectomy.
- LH-RH agonists and GnRH agonists. These drugs stop the body from making testosterone. They include goserelin (Zoladex), leuprolide (Lupron), and triptorelin (Trelstar Depot).
- Antiandrogens. These drugs often are used along with LH-RH agonists. Antiandrogens help block the body's supply of testosterone. There are steroidal antiandrogens and "pure" antiandrogens. The steroidal antiandrogens include megestrol (Megace). The "pure" or nonsteroidal antiandrogens include bicalutamide (Casodex), flutamide (Eulexin), and nilutamide (Nilandron).
- Orchiectomy. This surgery is considered to be hormone therapy. This is because removing the testicles, where more than 90% of the body's androgens are made, decreases testosterone levels. While removing the testicles may be the simplest way to reduce androgen levels, it is also permanent.
Sometimes androgen deprivation (orchiectomy or an LH-RH agonist) and an antiandrogen are used together for treatment. This is called a combined androgen blockade (CAB). There is also a triple androgen blockade (TAB) where another medicine is added, but research studies do not yet show if this works better than other treatments.
Other hormone therapies may include the use of medicines such as megestrol acetate, estrogen, ketoconazole, aminoglutethimide combined with hydrocortisone, and corticosteroids (prednisone, dexamethasone, and hydrocortisone).
Timing of hormone therapy
Some men choose to start hormone therapy only after they have symptoms. But many doctors recommend starting hormone therapy if cancer is found in the lymph nodes
during surgery to remove the prostate. Early treatment may allow men to live a little longer. Other doctors say to wait, because waiting will delay the bothersome side effects of hormone therapy.
Alternatives to conventional hormone therapy
- Intermittent androgen deprivation (IAD). This involves cycles of hormone therapy medicines. Taking breaks during hormone therapy gives men the chance to recover their ability to function sexually. It also gives relief from the other side effects of hormone therapy, including hot flashes and the effects on energy as well as bone and muscle mass. But the long-term survival outcome of IAD compared to conventional ADT is not yet known.
- Antiandrogen monotherapy. Antiandrogens are medicines that block the action of androgens in the body. By themselves, antiandrogens do not lower androgen levels, so this treatment is not considered hormone therapy or ADT. Treatment just with antiandrogens in men who only have a rising PSA after local therapy is easier than combining treatments. This is because antiandrogen medicines can be taken by mouth. And there are fewer problems with sexual function and loss of bone mass, so the overall quality of a man's life is better. How well antiandrogens work as therapy when used alone is controversial.
- Oral sequential hormone therapy. In this treatment, medicines that block the action of androgens in the body are taken with medicines that stop other changes that happen with androgens. Most studies have used finasteride (Proscar) or dutasteride (Avodart). This therapy usually causes a steady, painful increase in the size of breast tissue. This side effect may be prevented by radiation to the breasts before starting this hormone therapy. Or surgery may be needed to remove the extra breast tissue. Early studies have shown good results, but it is not yet known whether oral sequential hormone therapy helps men who have prostate cancer live longer.
Side effects of hormone therapy
Some of the side effects from hormone therapy will go away when a man who is taking medicine finishes his hormone therapy. For a man who has an orchiectomy, the side effects of sterility and loss of sexual interest are immediate and permanent.
Some side effects of hormone therapy may include:
- Hot flashes.
- Reduced muscle mass.
- Thin or brittle bones (osteoporosis).
- Increased body mass (BMI) and higher levels of fats in the blood.
- Breast enlargement (gynecomastia).
- Low red blood cell count (anemia) and fatigue.
- Nausea and/or diarrhea.
- Erection problems and decreased sex drive.
- Decrease in size of penis and testicles.
- Less hair on head and body.
- Depression.
See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems).
Long-term side effects of hormone therapy
The long-term side effects of hormone therapy, even for men taking medicine, are not known. Men who use hormone therapy may be at higher risk for getting type II diabetes or coronary artery disease.
One large study found that hormone therapy appears to be linked to a higher risk of death from heart problems in men who had surgery for localized prostate cancer.1
Hormone therapy and quality of life
The side effects of hormone therapy for prostate cancer often affect a man's quality of life. But there are treatments that can help with some of the side effects listed above. For example, exercise can help counteract the loss of muscle mass and will help with fatigue. There are medicines that can help with hot flashes, nausea, diarrhea, and bone loss. Treatments are available for erection problems and a reduced sex drive. Radiation before hormone therapy may help prevent breast enlargement. For men with depression, counseling and medicine may help. For more information, see the topic Depression.
Above all, talk with your doctor about any of the symptoms you have while you are taking hormone therapy. Your doctor may know about a local support group for men with prostate cancer.
| Author: | Bets Davis, MFA | Last Updated: June 27, 2008 |
| Medical Review: | E. Gregory Thompson, MD - Internal Medicine Christopher G. Wood, MD, FACS - Urology/Oncology | |
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