Is Mammography Screening for Breast Cancer Really Not Justifiable?
The consensus that breast screening is effective for women aged 50–59 years was shattered when Gotzsche and Olsen suggested that there are no reliable data to support screening by mammography. In practice, their concerns have been difficult to address because for many studies purporting to show effectiveness, adequate data have not been published to confirm that they were valid. Further, the trials in Canada for which such data are available did not show effectiveness of screening mammography. Since the 1990s, there has been an unprecedented reduction in breast cancer mortality in many countries. However, the reductions have no clear link to screening, but are probably due to the implementation of adjuvant treatment with chemotherapy and tamoxifen. Whether screening will have an additional impact in the future is unclear. After reviewing the published evidence, I conclude that the additional contribution of mammography over screening by good breast physical examinations and breast self examination is to detect good prognosis breast cancers, as the benefit of screening derives from the earlier detection of relatively advanced breast cancers, providing good therapy is given. If women choose mammography screening, they should understand that their risk of dying in the next few years may not be reduced.
KeywordsBreast Cancer Mammography Screening Breast Cancer Mortality Breast Screening Breast Screening Programme
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- Andersson I, Janzon L (1997) Reduced breast cancer mortality in women under age 50: updated results from the Malmö mammographic screening program. NCI Monogr 22:63–67Google Scholar
- Bassett AA (1985) Physical examination of the breast and breast self-examination. In: Miller AB (ed) Screening for cancer. Academic Press Inc. Orlando, pp 271–291Google Scholar
- Kerr M (1991) A case-control study of treatment adequacy and mortality from breast cancer for women age 40–49 years at entry into the National Breast Screening Study. Masters Thesis, University of Toronto, TorontoGoogle Scholar
- Miller AB (2000a) Organized breast cancer screening programs in Canada. Can Med Ass J 163:1150–1151Google Scholar
- Miller AB, Baines CJ, Turnbull C (1991) The role of the nurse-examiner in the National Breast Screening Study. Can J Pub Health 82:162–167Google Scholar
- National Institutes of Health Consensus Development Panel (1997) Consensus statement. NCI Monogr 22:vii–xiiGoogle Scholar
- Olsen O, Gotzsche PC (2001b) Screening for breast cancer with mammography (Cochrane Review). In: The Cochrane Library, Issue 4, Oxford: Update softwareGoogle Scholar
- Paquette D, Snider J, Bouchard F, Olivotto I, Bryant H, Decker K, et al (2000) Performance of screening mammography in organized programs in Canada in 1996. Can Med Ass J 163:1133–1138Google Scholar
- US Preventive Services Task Force (1996) Guide to clinical preventive services, 2nd edn. Washington DC. US Department of Health and Human ServicesGoogle Scholar