Hormone therapy for prostate cancer

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 and for different reasons during your cancer treatment.

Hormone therapy can be used:

• In advanced (metastatic) prostate cancer to shrink the cancer and slow the growth of tumors, which also might relieve signs and symptoms
• After treatment of prostate cancer, if the prostate-specific antigen (PSA) level remains high or starts rising.
• In locally advanced prostate cancer, to make external beam radiation therapy more effective in reducing the risk of recurrence
• In those with a high risk of recurrence after initial treatment to reduce that risk

Side effects of hormone therapy for prostate cancer can include:

• Loss of muscle mass
• Increased body fat
• Loss of sex drive
• Erectile dysfunction
• Bone thinning, which can lead to broken bones
• Hot flashes
• Decreased body hair, smaller genitalia and growth of breast tissue
• Fatigue
• Changes in behavior
• Problems with metabolism

Intermittent dosing

To minimize the side effects of hormone therapy medications, your doctor may recommend you take them for certain periods of time or until the PSA is very low. You might need to resume these medications if the disease recurs or progresses.

Early research shows this intermittent dosing of hormone therapy medications may reduce the risk of side effects. However, additional studies are needed to determine the long-term survival benefits of intermittent therapy.

Your doctor might suggest intermittent dosing if you have an elevated level of PSA in your blood, but no other evidence of spreading cancer.

As you consider hormone therapy for prostate cancer, discuss your options with your doctor. Approaches to hormone therapy for prostate cancer include:

• Medications that stop your body from producing testosterone. Certain medications — known as luteinizing hormone-releasing hormone (LHRH) or gonadotropin-releasing hormone (GnRH) agonists and antagonists — prevent your body's cells from receiving messages to make testosterone. As a result, your testicles stop producing testosterone.
• Medications that block testosterone from reaching cancer cells. These medications, known as anti-androgens, usually are given in conjunction with LHRH agonists. That's 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 agonists and antagonists

LHRH agonist and antagonist medications 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.

These medications include:

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

Testosterone levels may increase briefly (flare) for a few weeks after you receive an LHRH agonist. Degarelix is an exception that doesn't cause a testosterone flare.

Decreasing the risk of a flare is particularly important if you are experiencing pain or other symptoms due to cancer because an increase in testosterone can worsen those symptoms. To decrease the risk of a flare, your doctor might recommend you take an anti-androgen either before or along with an LHRH agonist.

Anti-androgens

Anti-androgens block testosterone from reaching cancer cells. These oral medications are usually prescribed along with an LHRH agonist or before taking an LHRH agonist.

Anti-androgens include:

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

Orchiectomy

You'll be given anesthetics to numb your groin area. The surgeon makes an incision in your groin and extracts the entire testicle through the opening, then repeats the procedure for your other testicle. Prosthetic testicles can be inserted if you choose.

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 after orchiectomy.

Other androgen-blocking medications

When prostate cancer persists or recurs, 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 (Yonsa, Zytiga)
• Corticosteroids, such as prednisone
• Enzalutamide (Xtandi)
• Ketoconazole
• Apalutamide (Erleada)

These other medications are generally used when advanced prostate cancer no longer responds to other hormone therapy treatments.

You'll meet with your cancer doctor regularly for follow-up visits while you're taking hormone therapy for prostate cancer. Your doctor will ask about any side effects you're experiencing. Many side effects can be controlled.

Depending on your circumstances, you may undergo tests to monitor your medical situation and watch for cancer recurrence or progression while you're taking hormone therapy. Results of these tests can give your doctor an idea of how you're responding to hormone therapy, and your therapy may be adjusted accordingly.