Hormone Therapy for Prostate Cancer (Androgen Deprivation Therapy, or ADT)
Hormone therapy for prostate cancer is also known as androgen deprivation therapy (ADT). Reference Prostate cancer Opens New Window cannot grow or survive without Reference androgens Opens New Window, which include Reference testosterone Opens New Window 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.
Hormone therapy may 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. It may be used when prostate cancer has spread outside the prostate (metastatic disease). In these cases, hormone therapy reduces pain and helps men live a little longer.Reference 1
Hormone therapy may be used to suppress prostate cancer cells, which is reflected in lower levels of prostate-specific antigen (PSA).
Hormone therapy may also be used as the main treatment for prostate cancer instead of surgery or radiation. But hormone therapy doesn't seem to help men ages 66 and older who have localized prostate cancer. These men live just as long with active surveillance.Reference 2
Taking medicines is one way to reduce androgens. Another way, used much less often, is surgery to remove the testicles, also known as an Reference orchiectomy.
- Reference LH-RH agonists and GnRH agonists. These drugs stop the body from making testosterone. They include goserelin (Zoladex), histrelin (Vantas), leuprolide (Lupron), and triptorelin (Trelstar).
- GnRH antagonists. These drugs stop the body from making testosterone. They work right away. And they avoid the flare caused by GnRH agonists, which can make symptoms worse for several weeks. One GnRH antagonist is degarelix (Firmagon).
- Androgen inhibitors. These are medicines that block enzymes that the body needs to make testosterone. They include enzalutamide (MDV3100), ketoconazole, and abiraterone (Zytiga), which is given along with prednisone.
- Reference 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, and nilutamide (Nilandron).
- Reference 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. Removing the testicles may be the simplest way to reduce androgen levels, but it is permanent.
Sometimes androgen deprivation (orchiectomy or an LH-RH agonist) and an antiandrogen are used together for treatment. This targets the testosterone made by the testicles and the adrenal glands. It is called a combined androgen blockade (CAB). According to research studies, men who had CAB that included flutamide or nilutamide lived longer than the men who had only androgen deprivation therapy.Reference 3
Other hormone therapies may include the use of medicines such as megestrol, estrogen, aminoglutethimide combined with hydrocortisone, and corticosteroids (prednisone, dexamethasone, and hydrocortisone).
Timing of hormone therapy
Research does not clearly show whether starting hormone therapy before symptoms appear allows men to live longer than if they waited until after symptoms appear to start taking medicine.Reference 3 Men who start hormone therapy almost always stay on it for the rest of their lives. So waiting until symptoms appear may allow men to delay the serious 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. 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. Antiandrogen monotherapy means taking antiandrogens without other hormone medicines.
Side effects of hormone therapy
The side effects of hormone therapy increase with the length of time that a man uses this 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.
Side effects of hormone therapy may include:
- Thin or brittle bones (Reference osteoporosis Opens New Window).
- Increased body mass (Reference BMI Opens New Window) and higher levels of fats in the blood.
- Reduced muscle mass.
- Low red blood cell count (Reference anemia Opens New Window) and fatigue.
- Increased risk for diabetes and heart disease.
- Emotional ups and downs.
Other side effects may include hot flashes, erection problems and reduced sex drive, breast enlargement, and cognitive impairment. Some men may experience Reference depression Opens New Window.
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. But hormone therapy has been linked to a higher risk for diabetes, cardiovascular disease, and a shorter life span.Reference 3
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.Reference 4
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. Low-dose 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 who have prostate cancer.
|By:||Reference Healthwise Staff||Last Revised: Reference September 12, 2012|
|Medical Review:||Reference E. Gregory Thompson, MD - Internal Medicine
Reference Christopher G. Wood, MD, FACS - Urology, Oncology