What is Hormone Therapy?
Hormone therapy is a treatment that lowers a man's testosterone, or hormone, levels. This therapy is also called ADT: androgen deprivation therapy. Testosterone, an important male sex hormone, is the main fuel for prostate cancer cells, so blocking it may slow the growth of those cells. Hormone therapy slows prostate cancer growth in men when prostate cancer has metastasized (spread) away from the prostate or returned after other treatments. It may also be used to shrink a local tumor that has not spread. There are several types of hormone therapy for prostate cancer treatment, including medications and surgery. Your doctor may prescribe a variety of ADT medication therapies over time.
Hormone Therapy with Surgery
Surgery to remove the testicles for hormone therapy is called orchiectomy or castration. When the testicles are removed, it stops the body from making the hormones that fuel prostate cancer. It is rarely used as a treatment choice in the United States. Men who choose this therapy want a one-time surgical treatment. They must be willing to have their testicles permanently removed and must be healthy enough to have surgery.
This simple surgery allows the patient to go home the same day. The surgeon makes a small cut in the scrotum (sac that holds the testicles). The testicles are detached from blood vessels and removed. The vas deferens (tube that carries sperm to the prostate before ejaculation) is detached. Then the sac is sewn up.
There are multiple benefits to undergoing orchiectomy to treat advanced prostate cancer. It is not expensive. It is simple and has few risks. It only needs to be performed once. It is effective right away. Testosterone levels drop dramatically. There is often fast relief from cancer symptoms.
Side effects to your body include infection and bleeding. Removing the testicles means the body stops making testosterone, so there is also a chance of the side effects listed below for hormone therapy. Other side effects of this surgery may be about body image due to the look of the genital area after surgery. Some men choose to have artificial testicles or saline implants placed in the scrotum to help the scrotum look the same as before surgery. Some men choose another surgery called subcapsular orchiectomy. This removes the glands inside the testicles, but it leaves the testicles themselves, so the scrotum looks normal.
Hormone Therapy with Medications
There are different types of hormone therapy available as injections or as pills that can be taken by mouth. Some of these therapies stop the body from producing luteinizing-hormone-releasing-hormone (LHRH, also called gonadotrophin releasing hormone, or GnRH). LHRH triggers the body to make testosterone. Other therapies stop prostate cells from being affected by testosterone by blocking hormone receptors. Sometimes, after the first shot, a blood test is done. This is done to check testosterone levels. You may also have tests to monitor your bone density during treatment.
With LHRH treatment there is no need for surgery. The main down side to LHRH treatment is the cost. The injections are more expensive than a one-time surgery. Check to see if your health insurance covers this option. Men who cannot or do not wish to have surgery are good candidates for this treatment.
There are different types of medical hormone therapy your doctor could prescribe to lower or stop your body's production of testosterone. After your testosterone levels drop to almost zero, you are at "castration level." It is the same as if your testicles were gone. Once testosterone levels drop, prostate cancer cells decrease in growth and proliferation.
Types of Medications
LHRH/GnRH agonists are drugs that lower testosterone levels. This hormone therapy is usually the first treatment for localized cancer. It is also used for cancer that has come back, whether or not it has spread. Men who cannot or do not wish to have surgery to remove their testicles are good candidates for these treatments.
When first given, agonists cause the body to produce a burst of testosterone (called a "flare"). Agonists are longer acting than natural LHRH. After the initial flare, the drug tricks your brain into thinking it does not need to produce LHRH/GnRH because it has enough. As a result, the testicles are not stimulated to produce testosterone. Your testosterone levels then drop by 90-95%. This is called the "castrate level." It is the same as if your testicles were gone. Once testosterone levels drop, prostate cells and cancer cells stop growing. This is because testosterone is not fueling their growth.
LHRH or GnRH agonists are given as shots or as small pellets placed under the skin. Based on the drug used, they are given from once every one, three or six months.
Some types of LHRH or GnRH agonist drugs are:
Side effects include the "flare up" from the agonist treatment. About 7-10 days later, these hormones stop being produced by your body. Other side effects may include bone pain and possible irreversible loss of the body's ability to make testosterone. The cost may be a burden if health insurance does not cover the treatment because the injections may be more expensive than a one-time surgery.
These drugs also lower testosterone, but more quickly. This is the second line of treatment for localized cancer or cancer that has come back. Men who cannot or do not wish to have surgery to remove their testicles are good candidates for these treatments.
Instead of flooding the pituitary gland with LHRH, they stop LHRH from binding to receptors. There is no testosterone flare with an LHRH/GnRH antagonist because the body does not get the signal to produce testosterone.
Antagonists are injected (shot) under the skin, in the buttocks or abdomen every month. It is done in the health care provider's office. You will stay in the office awhile after the shot. This is to make sure there is no allergic reaction. After the first shot, a blood test makes sure testosterone levels have dropped. You may also have tests to monitor bone density.
The LHRH or GnRH antagonist drug used is:
Side effects may include bone pain and possible irreversible loss of the body's ability to make testosterone. Side effects may be reversible, but depends on the length of time you are on treatment. The cost may be a burden if health insurance does not cover the treatment because the injections may be more expensive than a one-time surgery.
These drugs block testosterone by preventing the testicles from receiving the message to release testosterone. This therapy depends partly on where the cancer has spread and its effects.
This treatment stops testosterone by blocking the androgen receptors in the prostate cancer cells. Normally, testosterone would bind with these receptors to fuel growth of prostate cancer cells. With the receptors blocked, testosterone cannot "feed" the prostate. Using anti-androgens a few weeks before, or during, LHRH therapy may reduce "flare ups." Anti-androgens are also used after surgery or castration when hormone therapy stops working.
Anti-androgen drugs are taken as a tablet or pill and you should take the drug around the same time every day. This keeps a steady level of the drug in your body. Taking a dose the same time each day also lowers side effects like nausea or vomiting. If you forget to take a dose, you should not take a double dose.
Some types of anti-androgen drugs are:
Side effects may include nausea or vomiting. Anti-androgen therapy does not lower testosterone, so it may have fewer or milder side effects than surgery and medical hormone treatment.
CAB (combined androgen reducing treatment, with anti-androgens)
This method blends castration (by surgery or with the drugs described above) and antiandrogen drugs. The treatment blocks testosterone and stops it from binding to cancer cells. This therapy may be a good choice for you, but depends partly on where the cancer has spread and how you feel.
Normally, testosterone would bind with these receptors to fuels prostate cancer cell growth. With the receptors blocked, testosterone cannot "feed" the cells. The testicles produce almost all of the body's testosterone. To stop your testicles from making testosterone you can have surgery or take oral drugs. The rest of the testosterone is made by the adrenal glands. Antiandrogen therapy blocks testosterone made by the adrenal glands.
Your doctor may choose to use anti-androgens for a short period of time (one to two months). It may be used long term when androgen deprivation therapy (ADT) starts. Or, it may be used when other hormone therapies are no longer effective.
Androgen synthesis inhibitors
These drugs stop other parts of your body (and the cancer itself) from making more testosterone and its metabolites. Men newly diagnosed with metastatic hormone sensitive prostate cancer (mHSPC) or men with metastatic castration-resistant prostate cancer (mCRPC) may be good candidates for this therapy.
Androgen synthesis inhibitors may be taken by mouth as a pill. It stops your body from releasing the enzyme needed to make androgens in the adrenal glands, testicles and prostate tissue, resulting in reduced levels of testosterone and other androgens. Because of the way it works, this drug must be taken with an oral steroid called prednisone.
The androgen synthesis inhibitor drug used is:
Androgen receptor binding inhibitors
These drugs block testosterone from linking to prostate cancer cells (like anti-androgens). These drugs may be used in men with newly diagnosed mHSPC or mCRPC before or after chemotherapy.
Androgen receptor binding inhibitors are taken by mouth as a pill. You do not need to take a steroid with this drug. This drug blocks the androgen receptor at multiple sites to prevent cancer cells from growing. These drugs may slow down the spread of cancer. Some men have done very well with these options, combined with ADT drugs.
The androgen receptor binding inhibitor drugs used are:
Estrogens are female sex hormones and they can be used to block testosterone production in the testicles. Estrogen hormone therapy has side effects similar to androgen hormone therapy. But the use of estrogens may cause female sex characteristics to develop. This may include breast tenderness and swelling and other changes. Because of the side effects of estrogen hormone therapy, it is not often used today.
Hormone Therapy Side Effects
Unfortunately, hormone therapy may not work forever, and it does not cure the cancer. Over time, the cancer may grow in spite of the low hormone level. Other treatments are also needed to manage the cancer. Hormone therapies have many side effects. Learn what they are. Intermittent (not constant) hormone therapy may also be a good treatment option. Before starting any type of hormone therapy, talk with your health care provider.
Possible hormone therapy side effects include:
- Lower libido (sexual desire) in most men
- Erectile dysfunction (inability to have or keep a strong enough erection for sex)
- Hot flashes or sudden spread of warmth to the face, neck and upper body, heavy sweating
- Weight gain of 10 to 15 pounds. Dieting, eating fewer processed foods and exercising may reduce weight gain
- Mood swings
- Depression to include feeling loss of hope, loss of interest in enjoyable activities, not being able to concentrate or changes in appetite and sleeping
- Fatigue (feeling tired) that doesn't go away with rest or sleep
- Anemia (low red blood cell count) due to less oxygen getting to tissues and organs, causing tiredness or weakness
- Loss of muscle mass causing weakness or low strength
- Weak bones (loss of bone mineral density) or bones getting thinner, brittle and may break easier.
- Memory loss
- High cholesterol, especially LDL ("bad") cholesterol
- Breast nipple tenderness or increased breast tissue growth
- Increased risk of diabetes, 40% higher compared to men not on ADT
- Heart disease with only some studies showing men on ADT at higher risk for heart problems, so the effect of ADT on the heart is still unknown
There are many benefits and risks to each type of hormone therapy so be sure to ask questions to your doctor so you understand what is best for you.