Hormone therapy is a common treatment for metastatic prostate cancer. It is also called anti hormone therapy.
Metastatic prostate cancer is a cancer that has spread from the prostate to other parts of the body such as the bones.
What is hormone therapy?
Hormones occur naturally in your body. They control the growth and activity of normal cells. Testosterone is a male hormone mainly made by the testicles.
Prostate cancer usually depends on testosterone to grow. Hormone therapy blocks or lowers the amount of testosterone in the body.
Hormone therapy doesn't cure prostate cancer. But it can control or shrink the cancer and reduce symptoms. It can help you feel better and improve your quality of life for a time.
When you might have hormone therapy
Most men with metastatic prostate cancer have hormone therapy. You usually have it in combination with a chemotherapy drug called docetaxel.
Hormone therapy with chemotherapy is often very effective at controlling metastatic prostate cancer for many months. But sometimes the cancer can start to grow again. If this happens, you might hear your doctor saying that you have castration resistant prostate cancer. This means that hormone therapy is no longer working. Your doctor might suggest that you:
- have a different type of hormone therapy
- start a different type of treatment
Types of hormone therapy
There are 3 types of hormone therapy. This includes:
The injections work by blocking messages from a gland in the brain that tell the testicles to produce testosterone.
Luteinising hormone-releasing hormone agonists (LHRH agonists or LH blockers)
A gland in the brain called the pituitary gland makes luteinising hormone (LH). This controls the amount of testosterone made by the testicles. LH blockers stop the production of luteinising hormone. So the testicles stop making testosterone.
At first, the injections may make your symptoms worse. This is called tumour flare. Your doctor might recommend you take an anti androgen tablet such as flutamide to stop the tumour flare. You usually take flutamide for the first 4 to 6 weeks of your treatment.
Types of LH blockers include:
- leuprorelin (Prostap) – you have this every 4 weeks or 12 weeks
- goserelin acetate (Zoladex) – you have this every 4 weeks or 12 weeks
- buserelin (Suprefact) – you have this as an injection 3 times a day for 7 days and then a nasal spray 6 times a day
- triptorelin (Decapeptyl) – you have this once a month, 3 monthly or 6 monthly
Gonadotrophin-releasing hormone antagonist or GnRH blocker
This is another type of hormone injection. It stops messages from a part of the brain called the hypothalamus that tells the pituitary gland to produce luteinising hormone. Luteinising hormone tells the testicles to produce testosterone. So GnRH blockers stop the testicles making testosterone.
There is currently only one type called degarelix (Firmagon). When you start treatment, you have 2 injections on the same day. Then you have one injection a month. There's no risk of tumour flare with this treatment.
Hormone therapy tablets are usually anti androgen tablets or a drug called abiraterone.
Anti androgen tablets
These tablets stop testosterone from your testicles from getting to the cancer cells. Examples of anti androgens include:
- bicalutamide (Casodex) – you take it once a day
- flutamide (Drogenil) – you take it 3 times a day
- enzalutamide (Xtandi) – you take it once a day
The trade name for abiraterone is Zytiga. It is a type of hormone therapy that blocks an enzyme called cytochrome p17. Without this enzyme, the testicles and other body tissue can't make testosterone.
Abiraterone is usually a treatment for people who have had other types of hormone therapy or docetaxel. It is a tablet you take every day.
Finding out more about hormone treatment drugs
Check what is the name of the hormone treatment with your doctor or nurse, then take a look at our A to Z list of cancer drugs.
Surgery to remove the testicles (orchidectomy)
Surgery to remove your testicles isn’t a common way of lowering the amount of testosterone you make.
You usually only have surgery to remove your testicles if you need your testosterone reduced urgently. For example, if your cancer has spread to your bones and is pressing on your spinal cord, your doctors might want to reduce the amount of testosterone quickly.
Your doctors might also suggest surgery as an option if you don't want to have injections or tablets.
Before you start hormone treatment
You need to have blood tests before starting treatment. Your doctor will examine you and ask about your symptoms.
Sometimes it’s helpful to keep a symptom diary of how you feel. For example, if you have bone pain that is worse at night but gets better with painkillers.
How often you have hormone therapy
You usually have hormone therapy all the time (continuous therapy). Or you may have a few months of treatment and then a break (intermittent therapy).
You might have:
- one hormone therapy drug on its own
- two hormone therapies together
- hormone therapy with chemotherapy, such as docetaxel
Your doctor will talk to you about which hormone therapy they recommend and for how long you take it.
Where you have treatment
You might have your hormone treatment:
- at your GP’s surgery
- at home
- in the chemotherapy day unit
Your team will let you know where you will have your treatment.
Checking your hormone therapy is working
You have regular blood tests to check the level of a protein called prostate specific antigen (PSA). PSA is a protein made by both normal and cancerous prostate cells. It is in the blood in small amounts in all men, unless you have had the prostate gland completely removed.
While the hormone therapy is working, the level of PSA should stay stable or may go down. But if prostate cancer starts to grow and develop, the level of PSA may go up. This is hormone resistant prostate cancer or castrate resistant prostate cancer. Then your doctor may need to change your treatment. They will discuss this with you
When hormone therapy stops working
After some months or years, hormone treatment usually stops working and the cancer starts to grow again. Your doctor might recommend stopping or changing hormone treatment at this stage.
If you're having anti androgens and your PSA level has started to rise again your doctor might ask you to stop taking them. In some cases, this can cause the cancer to shrink and stop growing for some time. This is called anti androgen withdrawal response.
There are different treatment options for when hormone therapy stops working. This includes chemotherapy and steroids.
Side effects of hormone therapy are due to the low levels of testosterone in your body. Many men find that the side effects are often worse at the start of treatment. They usually settle down after a few weeks or months.
Some side effects are common to all hormone therapies for prostate cancer. Others vary from drug to drug. You might not have all of these side effects.
The main side effects are:
- difficulty getting an erection (impotence)
- hot flushes and sweating
- feeling tired and weak
- breast tenderness
- tumour flare
Side effects of long term treatment are:
- weight gain
- memory problems
- mood swings and depression
- bone thinning (osteoporosis)
- risk of early heart failure
Research and clinical trials
Researchers are interested in different ways of treating prostate cancer. They are using combinations of treatments and hormone therapy in clinical trials.