Advances in screening for breast cancer

Population-based mammographic screening: does 'informed choice' require any less than full disclosure to individuals of benefits, harms, limitations and consequences?

Mammographic screening is a public health intervention with benefits, harms and consequences. Assuming technical excellence and at least 70% participation, mammographic screening of women aged 50 years or over will reduce breast cancer mortality by 24%. Before the introduction of mammographic screening in Australia, the mortality rate from breast cancer for women in the target age group was 69.0 per 100,000. On the basis of this relative risk reduction, breast cancer mortality would be reduced to 46 per 100,000. However, for every breast cancer death averted, 10 additional cases of breast cancer will be diagnosed. As it is unknowable who will benefit from mammographic screening, it is unethical to claim that any given individual has been 'saved' through participation, especially in the absence of evidence that all-cause mortality will change. As women misunderstand their risks of breast cancer and the benefits and limitations of mammographic screening, public education is needed. As an individual's choice about screening is affected by the way benefits are framed, our public messages must be carefully scrutinised. It is impossible otherwise to assert that women are making an 'informed choice'. The decision of women who decline to participate must be respected. Public health expertise is crucial to ensure the rhetoric of 'informed choice' in cancer screening is realised.