Author Affiliations: Research Unit and Section for General Practice, University of Copenhagen, Copenhagen, Denmark.
We welcome the method by Welch and Frankel1 of estimating the probability (P) that a woman with a screen-detected cancer had her life saved by the screening program [P(life saved screen-detected cancer diagnosis)]. When using this model, the estimated probability ranges from 2.5% to 24.0%; for women aged 50 years, the estimated probability is 13%. We were intrigued by this number, since this probability previously has been estimated to be 4.8%.2 In his model, Keen2 used 2 parameters: (1) an estimate of the absolute risk reduction of breast cancer mortality with mammography screening and (2) the cumulative incidence of screen-detected cancers.
Heleno BM, Lindberg L, Brodersen J. Alternative Estimates for the Likelihood That a Woman With Screen-Detected Breast Cancer Has Had Her “Life Saved” by That Screening. Arch Intern Med. 2012;172(8):672-672. doi:10.1001/archinternmed.2012.352