Hormonal therapy for breast cancer in men

Hormones help to control how cells grow and what they do in the body. The hormone oestrogen encourages some breast cancers to grow.

Hormonal therapies reduce the levels of oestrogen in the body, or prevent it from attaching to the cancer cells. They only work for men with oestrogen-receptor (ER) positive cancers, which is about nine out of every ten men diagnosed with breast cancer. Hormonal therapy is one of the main treatments for breast cancer in men.

The most commonly used hormonal therapy is tamoxifen, but other therapies may be used. Hormonal therapy is usually given for at least five years to reduce the risk of breast cancer coming back.

You can also have hormonal therapy to treat breast cancer that comes back in the same area (recurrent cancer) or has spread to another part of the body (secondary breast cancer). If this happens, your doctor will offer you a different treatment to tamoxifen. You have it for as long as it’s working to control the cancer.

Types of hormonal therapy


Tamoxifen is an anti-oestrogen drug. It prevents oestrogen attaching to breast cancer cells and encouraging them to grow. You take it daily as a tablet, usually for five years.

Aromatase inhibitors

Aromatase inhibitors (AIs), such as letrozole, anastrozole and exemestane, also reduce oestrogen levels. You take them daily as a tablet. These drugs reduce oestrogen levels in men by stopping male hormones (androgens) being made into oestrogen. You usually have an AI if you cannot take tamoxifen, or if the cancer has come back or is no longer being helped by tamoxifen.

Some of the oestrogen in a man’s body is produced directly by the testicles, not by androgens. Because of this, your doctor may give you another drug called goserelin (Zoladex®) along with your AI.

Goserelin (Zoladex®)

The testicles are stimulated to make the hormones oestrogen and testosterone by signals received from the pituitary gland in the brain. Goserelin blocks these messages and stops the testicles making oestrogen and testosterone. Goserelin is given as a slow release implant that is injected just under the skin once every 1–3 months.

Fulvestrant (Faslodex®)

This is a newer type of anti-oestrogen that is given as an injection. Fulvestrant may occasionally be used if you have already had other hormonal therapies.

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