Breast cancer screening
The goal of cancer screening is to detect cancer or pre-cancerous changes at an early stage. The benefits of early detection include increased survival, increased treatment options and improved quality of life.1
Australia currently has 3 national screening programs for the early detection of various cancers.2
Population-wide testing for all early signs of various cancers can lead to overdiagnosis which may cause more harm than benefit.3 However, these particular programs have demonstrated an acceptable benefit in detecting cancer without a significant cost of overdiagnosis.2 Read more about which tests make a difference to patient outcomes.
Population screening for breast cancer
The Australian breast cancer screening program using mammography is associated with a 21–28% reduction in mortality from breast cancer in the target population – women aged 50–69 years.1 Cancers detected by the BreastScreen program are more likely to be smaller than those diagnosed outside the screening program.1
Women aged between 50 and 69 years of age should be encouraged to have a mammogram every 2 years.1,4
Overdiagnosis in breast cancer screening
Overdiagnosis is recognised as a risk factor for any screening program.3 In the UK it has been estimated that for every 10 000 women aged 50 years invited to screen for 20 years, 43 deaths from breast cancer would be prevented.5 But, 129 cases of breast cancer would be overdiagnosed. This is equal to one death from breast cancer being prevented for every three overdiagnosed breast cancer cases diagnosed and treated.5
For women aged 40–49 years the program sensitivity is lower increasing the rate of false negatives. In addition, the rate of invasive investigation to identify cancers is higher in women aged 40–44 compared with those aged 45–49.1 Because of this, routine screening for women 49 years old or younger is not recommended in the absence of risk factors.4
- Department of Health and Ageing. BreastScreen Australia Evaluation. Evaluation Final Report. 2009. http://www.cancerscreening.gov.au/internet/screening/publishing.nsf/Content/br-evaluation-report-cnt (accessed 7 June 2013).
- Australian Institute of Health and Welfare. Cancer in Australia an overview 2012. 2012. http://www.aihw.gov.au/publication-detail/?id=60129542359 (accessed 4 March 2013).
- Welch HG, Black WC. Overdiagnosis in cancer. J Natl Cancer Inst 2010;102:605–13. [PubMed]
- Guidelines for preventive activities in general practice (The Red Book) 8th Edition. Melbourne: The Royal Australian College of General Practitioners, 2012. http://www.racgp.org.au/your-practice/guidelines/redbook/ (accessed 8 January 2013).
- Independent UK Panel on Breast Cancer Screening. The benefits and harms of breast cancer screening: an independent review. Lancet 2012;380:1778–86. [PubMed]