Tamoxifen as a preventative therapy

Dr Julie Sharp, Senior Cancer Information Officer at Cancer Research UK, says:

"While the benefits of tamoxifen as a treatment for breast cancer are well known, its role in preventing the disease is still being investigated. This study has looked at the potential use of tamoxifen in general practice and has suggested that only a small number of these women are eligible for tamoxifen chemoprevention.

"A small proportion of the general population is at increased risk of breast cancer, for example because of a family history of the disease. Cancer Research UK is investigating the use of tamoxifen for chemoprevention in these high-risk women. Cancer Research UK have helped to fund large-scale clinical trial, IBIS I, that showed that tamoxifen can prevent the number of breast cancer cases by a third in women at high-risk of developing the disease. But the use of tamoxifen was also linked to a number of side-effects. For this reason, alternatives to tamoxifen are being investigated for the prevention of breast cancer in high-risk groups.

"Cancer Research UK are now co-funding a follow-on trial, IBIS-II, where doctors are looking at the use of anastrozole (arimidex) for the prevention of breast cancer in post-menopausal women at high-risk of the disease. It is thought that anastrozole may be as successful as tamoxifen in preventing breast cancer and it is also predicted to have fewer side-effects. These trials are ongoing and will provide vital information helping doctors can choose the best strategy to prevent breast cancer in women at greatest risk."

27 September 2004