Abstract
Clinical trials have shown that giving anti-oestrogens to healthy women can reduce the early incidence of breast cancer by approximately 40%. However, the large numbers of women treated, compared with the few who get breast cancer, together with the not insignificant toxicity and the unknown long-term clinical benefits and risks, makes this strategy of prevention versus treatment precarious. So how can we improve the odds for the successful use of endocrine chemoprevention?