The testicles produce testosterone, which can help prostate cancer grow. So removing the testicles can help to control the growth of prostate cancer. After removal of the testicles, the level of testosterone in the blood falls quickly. 

Removing your testicles is a type of hormone therapy for prostate cancer. It is not a common treatment. You're more likely to have injections or tablets to reduce the level of testosterone in your blood.

Some men prefer to have this surgery as it is one treatment compared to having regular injections. Orchidectomy is not reversible. You may find the removal of your testicles upsetting.