Hormone therapy for prostate cancer is treatment to stop the male hormone testosterone from reaching the prostate cancer cells in your body. Hormone therapy for prostate cancer is also called androgen deprivation therapy.

Most prostate cancer cells rely on testosterone to help them grow. Hormone therapy for prostate cancer cuts off the supply of testosterone or stops testosterone from reaching the cancer cells, causing cancer cells to die or to grow more slowly.

Hormone therapy for prostate cancer may involve medications, or it can involve surgery to remove the testicles.

Hormone therapy for prostate cancer is used to stop your body from producing the male hormone testosterone, which fuels the growth of prostate cancer cells.

Your doctor may recommend hormone therapy for prostate cancer as an option at different times during your cancer treatment and for different reasons, such as:

  • In advanced (metastatic) prostate cancer, hormone therapy can shrink the cancer and slow the growth of tumors, relieving signs and symptoms.
  • In prostate cancer that recurs after treatment, hormone therapy is one treatment men and their doctors can consider.
  • In locally advanced prostate cancer, hormone therapy may make external beam radiation therapy more effective.
  • In men with a high risk of recurrence after initial treatment, hormone therapy may reduce this risk.

Side effects of hormone therapy for prostate cancer may include:

  • Bone thinning
  • Erectile dysfunction
  • Fatigue
  • Growth of breast tissue
  • Heart disease
  • Hot flashes
  • Loss of sex drive
  • Loss of muscle mass
  • Memory problems
  • Weight gain

In general, the risk of side effects increases the longer you take hormone therapy medications.

Intermittent dosing may reduce side effects of medications

To minimize the side effects of hormone therapy medications, your doctor may recommend you take these medications only until prostate cancer responds to the treatment and stop taking them once the cancer is under control. You may need to resume these medications if the disease recurs or progresses.

Early research shows this intermittent dosing of hormone therapy drugs may reduce the risk of side effects. But long-term studies are needed to confirm that survival isn't negatively affected.

There are several options for hormone therapy for prostate cancer. Before you undergo hormone therapy for prostate cancer, talk to your doctor to decide which approach is best for you:

  • Medications that stop your body from producing testosterone. Medications known as luteinizing hormone-releasing hormone (LHRH) agonists and antagonists prevent cells in the body from receiving messages to make testosterone, causing the production of testosterone in the testicles to stop.
  • Medications that block testosterone from reaching cancer cells. Medications known as anti-androgens prevent testosterone from reaching your cancer cells. These medications usually are given in conjunction with LHRH agonists because LHRH agonists can cause a temporary increase in testosterone before testosterone levels decrease.
  • Surgery to remove the testicles (orchiectomy). Removing your testicles reduces testosterone levels in your body quickly and significantly. But unlike medication options, surgery to remove the testicles is permanent and irreversible.

LHRH agonist and antagonist medications — also called gonadotropin-releasing hormone (GnRH) agonists and antagonists — stop your body from producing testosterone.

These medications are injected under your skin or into a muscle monthly, every three months or every six months. Or they can be placed as an implant under your skin that slowly releases medication over a longer period of time.

Drugs typically used in this type of hormone therapy include:

  • Leuprolide (Lupron, Eligard)
  • Goserelin (Zoladex)
  • Triptorelin (Trelstar)
  • Histrelin (Vantas)
  • Degarelix (Firmagon)

Testosterone levels may increase briefly (flare) for a few weeks after you receive an LHRH agonist. Anti-androgen medications can help decrease the risk of a flare, so your doctor may recommend you take an anti-androgen either before or along with an LHRH agonist.

Protecting against effects of a flare is particularly important if you are experiencing pain or other symptoms due to cancer because an increase in testosterone can make those symptoms worse.

An exception to this is the LHRH antagonist degarelix, which doesn't cause a flare in testosterone.

Anti-androgens

These medications don't decrease hormone levels. Instead, anti-androgens block testosterone from reaching cancer cells.

Drugs typically used in this type of hormone therapy include:

  • Bicalutamide (Casodex)
  • Flutamide
  • Nilutamide (Nilandron)

Anti-androgens are given as oral medications. They are usually prescribed along with an LHRH agonist or before taking an LHRH agonist to decrease risks associated with the hormone flare that can be caused by an LHRH agonist.

Surgery to remove the testicles (orchiectomy)

To remove your testicle, your surgeon makes an incision in your groin and extracts the entire testicle through the opening. The procedure is repeated for your other testicle. Prosthetic testicles can be inserted if you choose. You'll receive anesthetics to numb the area during surgery.

All surgical procedures carry a risk of pain, bleeding and infection. Orchiectomy is usually performed as an outpatient procedure and doesn't require hospitalization. Typically, no additional hormone therapy is required following orchiectomy.

Other medications

When prostate cancer persists or recurs despite hormone therapy, other medications can be used to block testosterone in the body. Each medication targets testosterone in the body in a different way. These other medications include:

  • Abiraterone (Zytiga)
  • Corticosteroids, such as prednisone
  • Enzalutamide (Xtandi)
  • Ketoconazole

These other medications are generally reserved for men with advanced prostate cancer that no longer responds to other hormone therapy treatments.

Hormone therapy for prostate cancer doesn't cure the disease. Although this treatment can help to manage prostate cancer by causing cancer cells to die or grow more slowly, it isn't a permanent solution. Almost all prostate cancers eventually recur or progress despite hormone therapy. But hormone therapy may effectively slow prostate cancer for months or years.

Apr. 26, 2013