Biological approaches to breast cancer prevention

Breast cancer prevention is one of the most challenging issues modern oncology is trying to address. Different strategies for risk avoidance, chemopreventive measures and chemosuppressive treatments are being investigated from both experimental and clinical points of view. Unfortunately, age - the main risk factor - is unavoidable. Data available on other potentially modifiable aspects such as diet, childbearing and hormone-related risk factors are controversial. 'Westernization' of lifestyle, fatty diet and late pregnancies combined with manipulation of sex hormones by oral contraceptives and oestrogen replacement therapy are likely to increase the risk of developing breast cancer. Chemoprevention denotes prevention of cancer by use of pharmacological agents to inhibit or reverse the process of carcinogenesis. Among the compounds proposed for breast cancer prevention, major research is being conducted on retinoids (particulary the synthetic molecule, 4-hydroxyphenil retinamide), selenium and difluoromethylornithine. Chemosuppression relates to the action of antioestrogens such as tamoxifen on the promotion of breast cancer in postmenopausal women. A careful evaluation of the cost/benefit ratio for proposed measures of breast cancer prevention are compulsory prior to any recommendation to the public.