Recommendations on the prevention of breast cancer with tamoxifen and raloxifene

Tamoxifen is well established as adjuvant therapy for early breast cancer. Raloxifene, currently used to prevent and treat osteoporosis, has been shown in animal models to prevent the growth of new mammary cancers. In the latest of CMAJ�s series of clinical practice guidelines for the diagnosis and management of breast cancer, the Canadian Task Force on Preventive Health care and the Steering Committee on Clinical Practice Guidelines for the Care and Treatment of Breast Cancer examine the evidence surrounding the use of these agents for the prevention of breast cancer in women at normal, low and high risk.

The committee writes that there is fair evidence to recommend against the use of tamoxifen to reduce the risk of breast cancer in women at low or normal risk of disease. The committee also states that evidence supports counselling women at high risk � although the cutoff for defining high risk is arbitrary � on the potential benefits and harms of breast cancer prevention with tamoxifen. They also provide guidelines to assist physicians in counselling patients about the potential benefits and harms of chemoprevention.

Chemoprevention of breast cancer: a joint guideline from the Canadian Task Force on Preventive Health Care and the Steering Committee on CPGs for the Care and Treatment of Breast Cancer

� M. Levine, J-M. Moutquin, R. Walton, J. Feightner

Dr. Mark Levine is Chair of Health Canada�s Steering Committee on Clinical Practice Guidelines for the Care and Treatment of Breast Cancer, Hamilton.