HFHT's Practising Wisely Newsletter
For the whole healthcare team.
Issue 40: Breast Cancer Screening
October 31, 2017
Breast cancer is the most frequently diagnosed cause of death from cancer in women worldwide and the second leading cause of death from cancer in women in developed countries. Screening for breast cancer aims to reduce mortality from this cancer. Despite widespread screening programs, incidences of metastatic cancers (or advanced-stage cancers that have already spread and are therefore more deadly) have remained stable since 1975.

Twenty five year follow-up for breast cancer incidence and mortality of the Canadian National Breast Screening Study and published in the British Medical Journal concluded that:

"Annual mammography in women aged 40-59 does not reduce mortality from breast cancer beyond that of physical examination or usual care when adjuvant therapy for breast cancer is freely available." (see our Quick Links section for references made throughout this newsletter).
Data from the Surveillance, Epidemiology, and End Results (SEER) program, 1975 through 2012 and published in the New England Journal of Medicine in October, 2016 concluded that:

"Although the rate of detection of large tumours fell after the introduction of screening mammography, the more favourable size distribution was primarily the result of the additional detection of small tumours. Women were more likely to have breast cancer that was overdiagnosed than to have earlier detection of a tumour that was destined to become large. The reduction in breast cancer mortality after the implementation of screening mammography was predominantly the result of improved systemic therapy."

A Cochrane review published in June 2013 generated the data for the graphic below, essentially showing mammography screening reduced the number of deaths through breast cancer from 5 to 4 in 1,000 women:

(Trouble viewing the image below? Download a larger version )
As in the Choosing Wisely newsletter we sent on PSA and prostate cancer screening, it comes down to shared decision making in order to help women make their decision on screening mammography.

Policy needs to be re-evaluated and research needs to continue to look for better methods to reduce the illness and death associated with breast cancer.

Our next instalment will look at some patient information aids that will be useful to patients. Stay tuned!
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