The condition and the treatment
When prostate cancer has spread to another part of the body, it is called advanced or metastatic prostate cancer. In most men with prostate cancer, the hormone testosterone makes the cancer grow faster. So, prostate cancer can be treated with drugs that make the body produce less testosterone, or react to it in a different way. This is called androgen deprivation treatment.
After a time, the cancer stops responding to such treatments – this is known as 'hormone-relapsed' cancer.
Abiraterone (Zytiga) can block the production of androgen, a different hormone linked to prostate cancer.
NHS Choices may be a good place to find out more.