Hormone therapy for prostate cancer
Definition
Hormone therapy for prostate cancer uses surgery or drugs to lower the levels of male sex hormones in a man's body. This helps slow the growth of prostate cancer.
Alternative Names
Androgen deprivation therapy; ADT; Androgen suppression therapy; Combined androgen blockade; Orchiectomy - prostate cancer; Castration - prostate cancer
Male Hormones and Prostate Cancer
Androgens are male sex hormones. Testosterone is the main type of androgen. Most testosterone is made by the testicles. The adrenal glands also produce a small amount.
Androgens cause prostate cancer cells to grow. Hormone therapy for prostate cancer lowers the effect level of androgens in the body. It can do this by:
- Stopping the testicles from making androgens using surgery or medicines
- Blocking the action of androgens in the body
- Stopping the body from making androgens
When is Hormone Therapy Used?
Hormone therapy is almost never used for people with Stage I or Stage II prostate cancer.
It is mainly used for:
- Advanced cancer that has spread beyond the prostate gland
- Cancer that has failed to respond to surgery or radiation
- Cancer that has recurred
It may also be used:
- Before radiation or surgery to help shrink tumors
- Along with radiation therapy for cancer that is likely to recur
Drugs That Lower Androgen Levels
The most common treatment is to take drugs that lower the amount of androgens made by the testicles. One class of these drugs are luteinizing hormone-releasing hormone (LH-RH) analogs (injections). These drugs lower androgen levels just as well as surgery does. They are usually given with anti-androgens (oral tablets). This type of treatment is called androgen deprivation therapy or sometimes called "chemical castration."
Men who receive androgen deprivation therapy should have follow-up exams with the health care provider prescribing the drugs:
- Within 3 to 6 months after starting therapy
- At least once a year, to monitor blood pressure and perform blood sugar (glucose) and cholesterol tests
- To get PSA blood tests to monitor how well the therapy is working
LH-RH analogs are given as a shot anywhere from once a month to every 6 months. These drugs include:
- Leuprolide (Lupron, Eligard)
- Goserelin (Zoladex)
- Triptorelin(Trelstar)
LH-RH antagonists are another class of treatments that reduce androgen levels more quickly and have fewer side effects. These drugs include:
- Degarelix (Firmagon)
- Relugolix (Orgovyx), an oral drug that does not require injection
Some providers recommend stopping and restarting treatment (intermittent therapy). This approach appears to help reduce hormone therapy side effects. However, it is not clear if intermittent therapy works as well as continuous therapy. Some studies indicate that continuous therapy is more effective or that intermittent therapy should only be used for select cases of prostate cancer.
Surgery to remove the testicles (castration) stops the production of most androgens in the body. This also shrinks or stops prostate cancer from growing. While effective, most men do not choose this option.
Drugs That Block Androgen
Some drugs that work by blocking the effect of androgen on prostate cancer cells. They are called anti-androgens. These drugs are taken as pills. They are often used when medicines to lower androgen levels are no longer working as well.
Anti-androgens include:
- Flutamide (Eulexin)
- Bicalutamide (Casodex)
- Nilutamide (Nilandron)
Next generations anti-androgens are often used when first generation medicines to lower androgen levels are no longer working as well. These include:
- Enzalutamide (Xtandi)
- Apalutamide (Erleada)
- Darolutamide (Nubeqa)
Drugs That Stop the Body From Making Androgens
Androgens can be produced in other areas of the body, such as the adrenal glands. Some prostate cancer cells can also make androgens. Three drugs help to stop the body from making androgens from tissue other than the testicles.
Two medicines, ketoconazole (Nizoral) and aminoglutethimide (Cytradren), treat other diseases but are sometimes used to treat prostate cancer. The third, abiraterone (Zytiga) treats advanced prostate cancer that has spread to other places in the body.
When Hormone Therapy Stops Working
Over time, prostate cancer often becomes resistant to hormone therapy. This means that the cancer only needs low levels of androgen to grow. When this occurs, additional drugs or other treatments may be added.
Side Effects
Androgens have effects all over the body. So, treatments that lower these hormones can cause many different side effects. The longer you take these medicines, the more likely you are to have side effects.
They include:
- Trouble getting an erection and not being interested in sex
- Less interest in sex (reduced libido)
- Shrinking testicles and penis
- Hot flashes
- Weakened or broken bones
- Smaller, weaker muscles
- Changes in blood fats, such as cholesterol
- Changes in blood sugar
- Weight gain
- Mood swings
- Fatigue
- Growth of breast tissue, breast tenderness
Androgen deprivation therapy can increase the risks for diabetes and heart disease.
Weighing the Options
Deciding on hormonal therapy for prostate cancer can be a complex and difficult decision. The type of treatment you choose may depend on:
- Your risk for cancer coming back
- How advanced your cancer is
- Whether other treatments have stopped working
- Whether cancer has spread
Talking with your provider about your options and the benefits and risks of each treatment can help you make the best decision for you.
References
Eggener S. Hormonal therapy for prostate cancer. In: Partin AW, Dmochowski RR, Kavoussi LR, Peters CA, eds. Campbell-Walsh Urology. 12th ed. Philadelphia, PA: Elsevier; 2021:chap 161.
National Cancer Institute website. Hormone therapy for prostate cancer. www.cancer.gov/types/prostate/prostate-hormone-therapy-fact-sheet. Updated February 22, 2021. Accessed January 18, 2024.
National Cancer Institute website. Prostate cancer treatment (PDQ) - health professional version. www.cancer.gov/types/prostate/hp/prostate-treatment-pdq. Updated February 13, 2023. Accessed January 18, 2024.
National Comprehensive Cancer Network website. NCCN clinical practice guidelines in oncology (NCCN guidelines): prostate cancer. Version 4.2023. www.nccn.org/professionals/physician_gls/pdf/prostate.pdf. Updated September 7, 2023. Accessed January 18, 2024.
Reviewed By: Kelly L. Stratton, MD, FACS, Associate Professor, Department of Urology, University of Oklahoma Health Sciences Center, Oklahoma City, OK. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.
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