6/28/23, 12:25 AM Canadian National Breast Screening Study Pathway Feedback Search Clinical Topics Home Studies Canadian National Breast Screening Study Canadian National Breast Screening Study Trial question What is the role of annual mammography screening in women for breast cancer incidence? Study design Multi-center Open label RCT Population 89835 female patients Inclusion criteria: women aged 40-59 years with no history of breast cancer Key exclusion criteria: mammography in the previous 12 months; history of breast cancer; pregnancy Interventions N=44925 mammography (annual physical breast examinations) N=44910 no mammography (a single examination followed by usual care in the community) Primary outcome Deaths from breast cancer in follow-up period 1.1 % 1.12 1.11 0.8 % 0.6 % 0.3 % No significant difference 0.0 % Mammography No mammography No significant difference in deaths from breast cancer in the follow-up period (1.11% vs. 1.12%; HR 0.99, 99% CI 0.88 to 1.12) Secondary outcomes No significant difference in death from all causes in the follow-up period (10.66% vs. 10.44%; HR 1.02, 95% CI 0.98 to 1.06) Conclusion In women aged 40-59 years with no history of breast cancer, mammography was not superior to no mammography with respect to deaths from breast cancer in the follow-up period. https://web.pathway.md/studies/rectC1sjg3kuUflvg 1/2 6/28/23, 12:25 AM Canadian National Breast Screening Study Pathway Reference Anthony B Miller, Claus Wall, Cornelia J Baines et al. Twenty five year follow-up for breast cancer incidence and mortality of the Canadian National Breast Screening Study: randomised screening trial. BMJ. 2014 Feb 11;348:g366. Open reference URL https://web.pathway.md/studies/rectC1sjg3kuUflvg 2/2