Overview

Hormone therapy treats prostate cancer by lowering the level of certain hormones in the body. These hormones are called androgens. Prostate cancer needs androgens to grow. The main androgen is testosterone. Reducing the level of testosterone can slow the growth of prostate cancer and even shrink the tumours.

The testicles make most of the body's testosterone. Hormone therapy can be done in two ways.

• It is often done with medicines. These medicines stop the testicles from making testosterone or they block it.
• Less often, surgery is done to remove the testicles. (This is called an orchiectomy.)

Both types of hormone therapy can cause serious side effects. These include a greater chance of getting osteoporosis, heart disease, and diabetes.

Hormone therapy may also be called androgen deprivation therapy (ADT) or androgen suppression therapy.

Types of hormone therapy

Hormone therapy for prostate cancer can be done with medicines or surgery.

Medicines that may be used include:

LHRH agonists.

These medicines stop the testicles from making testosterone. At first they may cause a brief testosterone increase (flare) that can sometimes cause problems.

LHRH antagonists.

These medicines also stop the body from making testosterone. But they avoid the testosterone flare caused by LHRH agonists.

Androgen synthesis inhibitors.

These medicines block enzymes that the body needs to make testosterone. So they can lower testosterone levels more than other treatments.

Antiandrogens.

These medicines block the adrenal glands from making testosterone. An antiandrogen may be used along with an LHRH agonist or antiagonist. This is called combined androgen blockade.

Surgery to remove the testicles (bilateral orchiectomy) is another way to reduce testosterone. The testicles make most of the body's testosterone. Removing them lowers testosterone levels immediately.

Surgery is the simplest and quickest way to reduce androgen levels. But the effects are permanent.

Side effects

The side effects of hormone therapy for prostate cancer depend in part on the type of therapy you have. Your doctor can tell you what to expect. In general, possible side effects include:

• Erection problems and reduced sex drive.
• Thin or brittle bones (osteoporosis).
• Increased risk for diabetes and heart disease.
• Weight gain.
• Changes in appearance, such as thinning hair, smaller genitals, and larger breasts.
• Reduced muscle mass.
• Hot flashes.
• Fatigue.
• Mood swings.

Some of the side effects of hormone therapy medicines may go away after you stop taking the medicine. Surgery (bilateral orchiectomy) tends to cause fewer side effects, but any side effects will be permanent.

Be sure to tell your doctor about any problems you have. Treatment and healthy lifestyle changes can help with some side effects.