Androgen hormones are a group of sex hormones. During puberty, these hormones deepen your voice and make hair grow on your face and body. Testosterone and other androgen hormones also help prostate cancer cells grow and spread.
Hormone therapy is a treatment that lowers androgen production or blocks these hormones from getting into cancer cells. Although advanced prostate cancer isn't curable, hormone therapy can help slow or stop its growth.
This treatment includes a few different medicines and a surgery called orchiectomy that removes the testicles. Each type of hormone therapy lowers hormone levels and treats prostate cancer in a slightly different way.
Before you start on hormone therapy it helps to know your treatment options, how each medicine works, and how you take it.
Luteinizing Hormone-Releasing Hormone (LHRH) Agonists
Most of the testosterone that's made in your body comes from your testicles. It starts when a part of your brain, called the hypothalamus, sends out a hormone signal called luteinizing hormone-releasing hormone (LHRH). LHRH makes your pituitary gland send out luteinizing hormone (LH), which tells your testicles to make testosterone.
LHRH agonists are medicines that act like LHRH in your body. At first they tell your pituitary gland to make more LH, which raises testosterone levels. When LHRH levels get high, your pituitary gland stops making LH. This stops testosterone production.
Another name for LHRH agonists is gonadotropin-releasing hormone (GnRH) agonists. LHRH agonists and other hormone therapies are also called chemical castration because they lower androgen levels about the same amount as surgery to remove one or both testicles (orchiectomy).
LHRH agonists don't remove the testicles like surgery does, but they do make the testicles shrink over time. Here are some LHRH agonists used to treat prostate cancer.
Tumor flares and LHRH agonists
Any LHRH agonist may cause a surge of testosterone at first. Doctors call this a tumor flare.
During the flare your tumor could grow, but it should stop growing quickly. You might have bone pain if prostate cancer is in your bones or trouble peeing if you still have a prostate gland.
Taking an anti-androgen medicine for the first few weeks that you're on an LHRH agonist can help prevent a tumor flare.
LHRH Antagonists
Antagonists for LHRH also lower testosterone levels, but in a different way than agonists. LHRH antagonists stop your pituitary gland from making LH, which halts testosterone production.
LHRH antagonists lower testosterone levels faster than LHRH agonists --- and they don't cause tumor flare. These medicines are also a form of chemical castration.
Androgen Synthesis Inhibitors
Your testicles aren't the only parts of your body that make testosterone. The adrenal glands and prostate cancer cells also make small amounts. Even in small amounts, testosterone helps prostate cancer grow.
Androgen synthesis inhibitors block an enzyme your body needs to make testosterone called CYP17. Blocking CYP17 stops your adrenal glands and prostate cancer cells from making testosterone.
Combined treatment approach
Androgen synthesis inhibitors don't stop testosterone production in your testicles. If you didn’t have both testicles removed (bilateral orchiectomy), you might block all the androgens produced in your body with:
- An LHRH agonist
- An LHRH antagonist
Anti-Androgens
Androgens attach to proteins called receptors on your prostate cancer cells. Once attached, these hormones help prostate cancer grow. Anti-androgen medicines block these receptors so that androgens can't get to the cancer cells and help them grow.
You'll take both an anti-androgen medicine and an LHRH agonist if you haven't had a bilateral orchiectomy.
Together, these medicines lower androgen levels and stop androgens from fueling prostate cancer growth. This medicine combination is called a total androgen blockade.
First-generation anti-androgens
These were the first anti-androgen medicines approved to treat advanced prostate cancer, and still in use today. You take them with an LHRH agonist for a total androgen blockade unless you've had a bilateral orchiectomy.
Second-generation anti-androgens
These are newer anti-androgen medicines. They act like first-generation anti-androgens, but they're better at blocking the androgen receptors.
Sometimes second-generation anti-androgens work better against prostate cancer than first-generation ones. You may take an LHRH agonist if you haven't had a bilateral orchiectomy.
Orchiectomy
This surgery removes your testicles to stop most of the androgen production in your body. Afterward, your prostate cancer should slow down or stop growing. Orchiectomy is the easiest and least expensive way to stop most androgen production, but you can't reverse the surgery.
Hormone therapy or orchiectomy?
Hormone therapy keeps androgen levels low. But you have to stay on the medicine long-term for it to keep working against your cancer. Orchiectomy is another way to permanently lower your androgen levels instead of hormone therapy.
How is orchiectomy done?
Usually you have orchiectomy as an outpatient procedure, meaning that you'll go home the same day you have the surgery. You'll be asleep under general anesthesia during the surgery, so you will not feel anything as it happens.
The surgeon makes a cut in your pubic area or scrotum — the pouch that holds your testicles. Next, they remove your testicles.
Surgery may also remove your spermatic cord — the bundle of nerves and blood vessels that runs from your abdomen to each testicle. This is to prevent the cancer from spreading through the spermatic cord to other parts of your body.
If you are concerned about your appearance, you can have prosthetic testicles filled with salt water placed into your scrotum during the procedure. This will restore the look of your testicles after your surgery.
Your Treatment Plan
Hormone therapy isn't a cure for advanced prostate cancer. But it can help slow or stop your cancer for as long as possible. This treatment also relieves cancer symptoms and may improve your quality of life.
There are a few types of hormone therapy to choose from. Your doctor will help you select the best option for you based on your age, health, preferences, and other factors.
Your doctor and pharmacist can answer any questions you have about hormone therapy, including what side effects it might cause and which other medicines you take that it could interact with.
Hormone therapy isn't the only way to treat late-stage prostate cancer.
Clinical trials for prostate cancer
Another option is to enroll in a clinical trial of a new prostate cancer treatment. Ask your doctor if you're a good candidate for any studies.
Show Sources
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SOURCES:
American Cancer Society: "Hormone Therapy for Prostate Cancer," "Initial Treatment of Prostate Cancer, By Stage and Risk Group."
Cancer Research UK: "Hormone Therapy for Metastatic Prostate Cancer."
Cleveland Clinic: "Luteinizing Hormone," "Orchiectomy."
Daily Med: "Eulexin."
FDA: "Highlights of Prescribing Information: Casodex," "Highlights of Prescribing Information: Eligard," "Highlights of Prescribing Information: Erleada," "Highlights of Prescribing Information: Firmagon," "Highlights of Prescribing Information: Lupron Depot," "Highlights of Prescribing Information, Nubeqa," "Highlights of Prescribing Information: Orgovyx," "Highlights of Prescribing Information: Trelstar," "Highlights of Prescribing Information: Xtandi," "Highlights of Prescribing Information: Yonsa," "Highlights of Prescribing Information: Zoladex," "Highlights of Prescribing Information: Zytiga."
Journal of Hematology, Oncology, Pharmacy: "Comparison of Second-Generation Antiandrogens for the Treatment of Prostate Cancer."
MedlinePlus: "Goserelin Implant," "Leuprolide Injection," "Relugolix," "Triptorelin Injection."
National Cancer Institute: "Hormone Therapy for Prostate Cancer," "Luteinizing Hormone-Releasing Hormone Agonist," "Luteinizing Hormone-Releasing Hormone Antagonist."
Sanofi: "Nilandron Prescribing Information."
UpToDate: "Patient Education: Treatment for Advanced Prostate Cancer (Beyond the Basics)."
Zoladex: "Getting Started with Zoladex."
