Different estimates of overdiagnosed women and saved lives from breast cancer in different meta-analyses and trials. Euroscreen: estimates derived from a review of observational studies, where estimates of mortality reduction from case–control studies are included . UK Independent review: estimates on relative effect derived from randomized trials of mammography screening and applied to UK national rates for women aged 55 to 79 years . UK Observational: estimates based on 31% overdiagnosis  and 13 to 17% reduction in mortality from breast cancer  and applied to the observed incidence of invasive breast cancer (women aged 50 to 69 years) and mortality (women aged 55 to 74 years) in the UK in 2007 ; this resulted in 2 to 3 prevented deaths from breast cancer. Cochrane review: estimates from the randomized trials of mammography screening . The Cochrane review does not assume the effect of mammography screening to last for 20 years as is assumed in the other estimates, but relates to what was observed in the randomized trials .