Androgen Deprivation Therapy (ADT)

What is ADT?

• Androgens are hormones that promote male characteristics such as facial hair, sexual function and muscle mass. Testosterone is the main androgen.
• Prostate cancer cells need androgens to grow.
• Androgen deprivation therapy (ADT) is a type of treatment for prostate cancer that blocks the effects of androgens and can slow prostate cancer growth.
•  “Hormone therapy” is another name for ADT.
• This therapy affects the whole body rather than a particular area.

ADT is usually given as pills or injections. In rare cases it can involve surgery to remove one or both of the testicles.

ADT is used to slow the growth of prostate cancer and can also help manage some of the symptoms associated with advanced cancer.

• Cancer that has spread outside the prostate
• Recurrence of prostate cancer after another therapy has been used
• Men who are at high risk of experiencing cancer recurrence after surgery or radiation therapy

What are androgens?

Androgens are male sex hormones.  The two most common are testosterone and dihydrotestosterone (DHT).  Women have small amounts of androgens too.  Like all hormones, androgens affect the actions of cells and tissues in the body.  Most testosterone is produced in the testicles, but a small amount is made by the adrenal glands (just above the kidneys).  Prostate cancer cells can also produce testosterone.
 
What do androgens and prostate cancer have to do with each other?
Androgens are needed to ensure that the prostate grows and functions normally.  Androgens can lead to prostate cancer, because they bind to and activate (turn on) the ‘androgen receptor’, a protein that is produced by the cells in the prostate gland.   Once these androgen receptors have been bound to androgen, they then stimulate certain genes that cause prostate cells to grow. 
 
At early stages of prostate cancer, prostate cancers “feed off” androgens, depending on them to grow.  These types of prostate cancers are known as “androgen-dependent” or “androgen-sensitive”.  Androgen Deprivation Therapy (ADT) works to ‘deprive’ these prostate cells of androgen, thus inhibiting their development.
 
Unfortunately in men with more advanced cancer, most prostate cancers will eventually continue to grow even when there is a low level of androgens in the body – a phenomenon known as “castration resistant prostate cancer”