• The pituitary gland is the size of a pea and is found underneath your brain. 
• It makes luteinising hormone. 
• This controls the amount of testosterone made by your testicles. 

Luteinising hormone-releasing hormone agonists (LHRH agonists)

• LHRH agonists stop the pituitary gland from making luteinising hormone. This stops the testicles from making testosterone.
• Your symptoms can get worse after the first injection (tumour flare). 

Examples of hormone injections are:

• Goserelin (Zoladex) is a small implant given by injection every 28 days or three-monthly
• Leuprorelin (Prostap) is given monthly or three-monthly
• Triptorelin (Decapeptyl) is given four-weekly, three-monthly or every 24 weeks. 

Gonadotrophin-releasing hormone antagonist (GnRH antagonist)

• These work in a slightly different way to LHRH agonists. But your testicles will still make less testosterone. 
• You will not have tumour flare with these injections. 
• This is mostly for people who have cancer that has spread to their spine. There is only one injection available in the UK. It is called degarelix (Firmagon). 

When is hormone therapy used? 

• Hormone therapy is used in different ways. This will depend on the stage and the grade of your cancer.

Early stage (localised prostate cancer)

• This is when the cancer is still within the prostate. 
  • You may be offered a course of hormone therapy injections with your radiotherapy.
  • Hormone therapy can help to shrink your prostate and the cancer inside. This can help the radiotherapy to work better.
  • You may have the hormone therapy before, during or after your radiotherapy. Your doctor will decide on how long you need to take the hormone therapy. This can be from three months up to three years. 

Locally advanced prostate cancer

• This is when your cancer has spread just outside your prostate.
• You may have hormone therapy injections:
  • With your radiotherapy. You may have the hormone therapy before, during or after your radiotherapy.

  • As a treatment on its own. This may happen if you are not able to have radiotherapy or surgery. You may also have regular monitoring.

     

Metastatic prostate cancer

• You will be given hormone therapy on its own or alongside another treatment, e.g. hormone therapy tablets.
• This can happen if your cancer has started to grow again while you are on hormone therapy injections. This is called castration-resistant prostate cancer. 
• Hormone therapy is usually a lifelong treatment at this stage.

• Testosterone levels in your body rise after the first injection. This could make your symptoms worse. This is called tumour flare. 
• Your doctor will usually give you a course of hormone tablets. This will protect you from this ‘flare’.  You may start the tablets before your first injection. You usually take the tablets for about three-to-six weeks. 

• You may have your first injection at the hospital. But often it is done in your GP surgery. All of your follow-up injections will usually be done at your GP surgery.

   

• If you are having injections, these may cause brief discomfort. 

• Anyone staying on hormone therapy should have a yearly check-up with their doctor. They will check your:
  • Blood pressure
  • Cholesterol
  • Blood sugars – to test for diabetes.
• They should also talk to you about your bone health and keeping fit.

• You will have regular check-ups with your doctor or specialist nurse.
• This will include monitoring of your PSA level.
• This will probably fall while you are on hormone therapy. If it starts to rise again, your doctor will talk to you about other treatment options. 
• Visit our page about PSA tests for more information (this will open in a new tab).

• When you are on hormone therapy, you will have your PSA level checked regularly. 
• If the hormone therapy is working, your PSA level will stay the same or go down. 
• If your PSA starts to go up, it may mean that your cancer has started to grow again. 
• When the hormone therapy stops working, this is called castrate -resistant prostate cancer. You may also hear it called hormone- resistant prostate cancer.
• If this happens, your doctor will talk to you about starting a different treatment or mix of treatments. This may include a different type of hormone therapy. 
• If you are having hormone therapy injections and become resistant, you will stay on the injections. 

• Hormone therapy may affect your ability to father a child. It will affect your:
  • Desire for sex
  • Your ability to have an erection
  • Sperm production.
• It may mean that you will have problems getting someone pregnant. 
• If you think you may want children, please talk to your doctor before starting treatment. 
• You may be able to have some of your sperm saved and frozen. This is called sperm banking or sperm cryopreservation. You can learn more about sperm banking on the Human Fertilisation and Embryology Authority website (this link will open in an external tab). 
• Cancer Research UK also have information about sperm collection and storage (this link will open in an external tab).