preventing your body from making testosterone
blocking testosterone from reaching the prostate cancer cells
The type of hormone therapy you may be offered depends on your type of cancer, if you’ve had any other treatments, and personal preferences.
Why is testosterone
so important here?
Testosterone is a normal hormone your body produces – mostly in the testicles. It plays a role in a man’s appearance, sexual development, sperm production, and sex drive. It impacts your erections and can affect prostate growth. It’s a critical hormone that your body uses for many other functions, including building your muscle and bone mass.
But prostate cancer cells use testosterone to grow and spread — think of testosterone acting like a ‘fertiliser’ for prostate cancer. Lowering testosterone in the body — either with surgery or medications — can help kill or slow down some prostate cancer cells.
What are the different ways
to lower testosterone?
This type of hormone therapy lowers the amount of testosterone made by your testicles.
There are two commonly used types:
LHRH stands for luteinising hormone-releasing hormone. These medications prevent your testicles from receiving the message from your brain (with LHRH being the messenger) to produce testosterone.
Examples of LHRH agonists include leuprolide/leuprorelin (Prostap, Eligard) and goserelin (Zoladex) which is an implant.
GnRH stands for gonadotropin-releasing hormone. Similar to LHRH agonists, these medications also prevent the testicles from making testosterone.
Degarelix (Firmagon) is an example of a GnRH antagonist.
Both are commonly used to treat prostate cancer that has spread to other locations like bones and lymph nodes (advanced prostate cancer). They can also be used along with radiation therapy (radiotherapy) in less advanced prostate cancer.
Depending on the specific medication, it can be given:
once a month
once every 3, 4 or 6 months
once a year
Speak to your doctor about the availability of these medicines and what your exact treatment plan might be.
Anti-androgens work by preventing testosterone from getting to and acting on the prostate cancer cells.
They’re usually not used on their own to treat prostate cancer but combined with other hormone therapies or treatments.
Examples of older anti-androgens include flutamide (Drogenil), Cyproterone acetate (Cyprostat) and bicalutamide (Casodex). Examples of newer anti-androgens include enzalutamide (Xtandi) and apalutamide (Erleada).
Some anti-androgens also work by preventing cells (including prostate cancer cells) from making testosterone. This includes the drug, abiraterone acetate (Zytiga).
During an orchiectomy, both testicles are removed with surgery so there are no testicles to produce testosterone.
An orchiectomy may be offered to men who need long-term hormone therapy.
The surgery is irreversible, meaning you can't undo it later. So if you are considering an orchiectomy, your doctor may suggest trying other forms of hormone therapy first to see how your body responds to low levels of testosterone.
With intermittent hormone therapy, hormone treatment will be paused once your PSA levels drop and stay stable. Some doctors call this the "off" phase. If PSA levels and testosterone start to rise, therapy will be started again. One major benefit to this type of treatment is that your side effects might be relieved during the off times.
When is hormone
Hormone therapy may be used at many points during the management of prostate cancer. It may also be used alongside other treatments for prostate cancer. On its own, it doesn't cure cancer. For men with advanced prostate cancer, hormone therapy is used to try and keep cancer from growing, which hopefully improves your quality of life and how long you may live.
If you have localised prostate cancer (early-stage cancer that has not spread outside the prostate gland), hormone therapy can be used to increase the effectiveness of your primary treatment.
It may be used with the following treatments:
radiation therapy - often
chemotherapy - usually
surgery - rarely
HIFU - sometimes
With locally advanced prostate cancer (when cancer has spread outside the prostate to the immediate surrounding area in the pelvis), hormone therapy is offered before, after and during radiation therapy (radiotherapy) to increase its effectiveness.
With advanced prostate cancer (when cancer has spread to organs, bones and lymph nodes outside the pelvis), hormone therapy is likely to be a life-long treatment. While advanced prostate cancer cannot be cured, the disease may be controlled using hormone therapy. Prostate cancer treated with hormone therapy may become resistant to this treatment over years and you may need other treatments.
During treatment, you’ll have regular PSA tests to see how well it’s working. You may also have your testosterone levels checked regularly, to make sure the hormone therapy is lowering your testosterone. If your PSA level goes down, it can mean your treatment is working as planned. The speed at which it falls and how much it falls will be different from one individual to another.
However, if your PSA levels keep rising, your doctor will talk to you about other treatment options. Consistently rising PSA levels can mean the hormone therapy is not working well.