Topic Overview

Hormone therapy for prostate cancer is also known as androgen deprivation therapy (ADT). Prostate cancer cannot grow or survive without androgens, which include testosterone and other male hormones. Hormone therapy decreases the amount of androgens in a man's body. Reducing androgens can slow the growth of the cancer and even shrink the tumor.

Hormone therapy may be used along with radiation treatment when there is a high risk of the cancer returning. Or hormone therapy may be used after surgery or radiation if any cancer remains.

Hormone therapy may also help men who have cancer that has spread and who cannot have surgery or radiation. It may be used when prostate cancer has spread outside the prostate (metastatic disease). In these cases, hormone therapy reduces pain and helps men live a little longer.¹

Hormone therapy may be used to suppress prostate cancer cells, which is reflected in lower levels of prostate-specific antigen (PSA).

Hormone therapy may also be used as the main treatment for prostate cancer instead of surgery or radiation. But hormone therapy doesn't seem to help men ages 66 and older who have localized prostate cancer. These men live just as long with active surveillance.²

Taking medicines is one way to reduce androgens. Another way, used much less often, is surgery to remove the testicles, also known as an orchiectomy.

• LH-RH agonists and GnRH agonists. These drugs stop the body from making testosterone. They include goserelin (Zoladex), leuprolide (Lupron), and triptorelin (Trelstar).
• GnRH antagonists. These drugs stop the body from making testosterone. They work right away. And they avoid the flare caused by GnRH agonists, which can make symptoms worse for several weeks. One GnRH antagonist is degarelix (Firmagon).
• Antiandrogens. These drugs often are used along with LH-RH agonists. Antiandrogens help block the body's supply of testosterone. There are steroidal antiandrogens and "pure" antiandrogens. The steroidal antiandrogens include megestrol (Megace). The "pure" or nonsteroidal antiandrogens include bicalutamide (Casodex), flutamide, and nilutamide (Nilandron).
• Orchiectomy. This surgery is considered to be hormone therapy. This is because removing the testicles, where more than 90% of the body's androgens are made, decreases testosterone levels. Removing the testicles may be the simplest way to reduce androgen levels, but it is permanent.

Sometimes androgen deprivation (orchiectomy or an LH-RH agonist) and an antiandrogen are used together for treatment. This is called a combined androgen blockade (CAB). There is also a triple androgen blockade (TAB) where another medicine is added. But research doesn't yet show that TAB works better than other treatments.⁴