ABSTRACT
Breast cancer incidence rates vary widely around the world, influenced by population demographics and lifestyle. World age-adjusted incidence rates are 20 per 100 000 in China compared with 90 per 100 000 in the Netherlands and USA.1 Epidemiological models of breast cancer focus on lifetime exposure to the mitogenic effects of oestrogen, including early age at menarche, late age at first birth, parity, late age at menopause, use of oral contraceptive, hormone replacement therapy (HRT), obesity and lack of physical activity.2 In the UK, the age-specific incidence rate rises fourfold between the ages of 35 and 70 years; the risk of developing breast cancer by the age of 85 years is 1 in 10. Approximately 40 000 UK women and a few hundred men develop breast cancer every year. Thirteen thousand of these patients die of the disease annually, representing 22 per cent of UK cancer mortality. Between 1989 and 2002, there was a 28 per cent reduction in UK breast cancer mortality, despite rising incidence. The reduction is attributed to more effective treatments and the national mammographic screening programme.
