ABC of Breast Diseases: Screening for Breast CancerBMJ 1994; 309 doi: https://doi.org/10.1136/bmj.309.6961.1076 (Published 22 October 1994) Cite this as: BMJ 1994;309:1076
- R W Blamey,
- A R M Wilson,
- J Patnick,
- J M Dixon
Lack of knowledge of the pathogenesis of breast cancer means that primary prevention is currently a distant prospect. Screening represents an alternative approach to try to reduce mortality from breast cancer.
The aim of screening is to detect breast cancer when it is small and before it has had the chance to spread
Methods of screening
There is no evidence that clinical examination, breast ultrasonography, and teaching self examination of the breast are effective tools in screening for breast cancer. Randomised controlled trials have shown, however, that screening by mammography can significantly reduce mortality from breast cancer. Mortality can be reduced by up to 40% in women who attend for screening, and the benefit is greatest in women aged over 50. Recently published data from the combined Swedish trials showed an overall reduction in breast cancer mortality of 29% during 12 years of follow up in women aged over 50 who were invited to attend screening and a 13% reduction in younger women.
Screening tests should be simple to apply, cheap, easy to perform, easy and unambiguous to interpret, and able to identify women with disease and exclude those without disease. Mammography is expensive; it requires high technology machinery, special film and dedicated processing, and highly trained radiologists to interpret the films; and it detects only 95% of all breast cancers. It is, however, the best screening tool available for detecting breast cancer and is the only screening method for any malignancy which has been shown to be of value in randomised trials.
Organisational aspects of screening
Over 70% of the target population must accept the invitation to participate if a screening programme is to significantly reduce mortality. If fewer participate the costs …