TY - JOUR T1 - Both a stage shift and changes in stage-specific survival have contributed to reductions in breast cancer mortality JF - Evidence Based Medicine JO - Evid Based Med SP - 76 LP - 76 DO - 10.1136/ebmed-2016-110632 VL - 22 IS - 2 AU - Stephen W Duffy AU - Ruth Etzioni AU - Peter Sasieni Y1 - 2017/04/01 UR - http://ebm.bmj.com/content/22/2/76.abstract N2 - Commentary on: Welch HG, Prorok PC, O'Malley AJ, et al. Breast-cancer tumor size, overdiagnosis, and mammography screening effectiveness. N Engl J Med 2016;375:1438–47.OpenUrlCrossRefPubMedSince randomised trials demonstrated a reduction in breast cancer mortality with mammographic screening, such screening has become widespread in developed countries, and mortality from breast cancer has declined in recent decades.1 There is interest in quantifying the proportion of this mortality reduction attributable to screening and that attributable to improvements in treatment.This paper reported on analysis of breast cancer incidence and case death in women aged 40 years and over in the USA by tumour size. The authors compared prescreening results (1975–1979) with postscreening (2008–2012 for size distribution, 2000–2002 for 10-year case death). They used a similar approach to Duffy et al2 positing that reductions in … ER -