Several hormonal therapies used to treat prostate cancer, including Casodex®, can cause pain and swelling of the breasts. This is called gynaecomastia.

Treatments for gynaecomastia caused by hormonal therapy for prostate cancer include tamoxifen, radiotherapy, and surgery.

Treatment depends on how long you have had the swelling for. Early changes in the breast tissue, that happen during the first year or so, may be reversible with treatments such as tamoxifen or radiotherapy. But, men who have had breast swelling for longer than this may have changes in the breast tissue that aren't reversible. This is because fibrous or scar tissue may have developed in the breast tissue. If this happens surgery may be an option.

Tamoxifen

Tamoxifen is a hormonal treatment. It is taken as a tablet and has been shown to be effective in up to 8 out of 10 men who have recent breast swelling or tenderness. Gynaecomastia is not linked to breast cancer although tamoxifen can be used to treat both conditions.

All men and women produce both oestrogen and testosterone. Normally, men’s higher levels of testosterone block (oppose) the effects of oestrogen on their bodies. But hormonal therapy for prostate cancer, can upset this balance. The effects of oestrogen on the breasts are increased, causing breast tissue to grow.

Tamoxifen works by stopping oestrogen from reaching breast tissue without altering the effectiveness of the hormonal therapy treating prostate cancer.

Radiotherapy

Radiotherapy is most effective when used to prevent breast swelling but can also be used to treat it. It can help up to about 6 out of every 10 men. It reduces breast swelling and relieves breast tenderness in about3 in10 men with gynaecomastia. And, in a further 3men in10breast symptoms stay the same and don't get any worse.

Radiotherapy is given as an out-patient treatment and takes only a few minutes. It is given to both breasts, either as a single treatment or over 2-3 days. Some men may notice a slight irritation and redness of the skin around their nipple after radiotherapy, but this usually goes away within about 5 weeks.

Surgery

If radiotherapy or tamoxifen aren’t helpful at reducing breast swelling surgery may be an option.

The operation involves removing as much of the breast tissue as possible while preserving the nipple. It is a specialised operation and should be done by a breast surgeon or a plastic surgeon.

Complications following surgery aren't common. Short term problems include; blood collecting under the skin (haematoma), fluid collecting under the skin (seroma), and infection. Long term side effects are rare but may include altered sensation of the breast or nipple, the nipple flattening or turning in or even loss of the nipple.

Liposuction, sucking out fatty tissue in the breast, is not usually helpful. This is because, in men having hormonal treatment for prostate cancer, gynaecomastia is caused by an increase in glandular tissue rather than fatty tissue.

Your specialist will be able to talk these treatment options through with you.

Reference

• Di Lorenzo, et al (2005) Management of gynaecomastia in patients with prostate cancer: a systematic review. Lancet Oncology 6 972-979.