Hormonal therapy
Most breast cancers need the hormone oestrogen in order to grow. Oestrogen is the female sex hormone, but men have a small amount circulating in their bloodstream. Hormonal therapy is very effective in reducing the amount of oestrogen in the body, and is used to try to prevent the cancer from returning after surgery. Hormonal therapy may also be used to shrink the cancer if it returns after initial surgery.

Tamoxifen Tamoxifen is the hormonal therapy that is commonly used to treat breast cancer. It works by attaching itself to the oestrogen receptors on the surface of the cancer cells. This prevents oestrogen from entering the cells, and can stop the cells from growing or dividing. Men usually have similar side effects to women who take tamoxifen (such as hot flushes or loss of sex drive). Men may also experience difficulty in achieving erections.