Breast Cancer Mortality in Mammographic Screening in Europe: A Review of Incidence-Based Mortality Studies

Abstract

Objectives To estimate the impact of service mammography screening on breast cancer mortality using European incidence-based mortality (IBM) studies (or refined mortality studies). IBM studies include only breast cancer deaths occurring in women with breast cancer diagnosed after their first invitation to screening. Methods We conducted a literature review and identified 20 publications based on IBM studies. They were classified according to the method used for estimating the expected breast cancer mortality in the absence of screening: (1) women not yet invited; (2) historical data from the same region as well as from historical and current data from a region without screening; and (3) historical comparison group combined with data for non-participants. Results The estimated effect of mammography screening on breast cancer mortality varied across studies. The relative risks were 0.76 -0.81 in group 1; 0.75 -0.90 in group 2; and 0.52 -0.89 in group 3. Study databases overlapped in both Swedish and Finnish studies, adjustment for lead time was not optimal in all studies, and some studies had other methodological limitations. There was less variability in the relative risks after allowing for the methodological shortcomings. Conclusions Based on evidence from the most methodologically sound IBM studies, the most likely impact of European service mammography screening programmes was a breast cancer mortality reduction of 26% (95% confidence interval 13 -36%) among women invited for screening and followed up for 6-11 years.

Quantra™ should be considered a tool for two-grade scale mammographic breast density classification

“…Qualitative MBD assessment was performed by radiologists using the fourth edition BI-RADS scheme on a discrete scale (1)(2)(3)(4). For this study, BI-RADS breast density assessment was performed in two phases.…”

“…1,2 It has been shown that 30% reduction in breast cancer mortality is partly attributable to improved knowledge of its risk factors and advances in early detection and treatment strategies. 3,4 Breast density refers to the proportion of the breast that is composed of fibroglandular tissue 5 and is related to established breast cancer risk factors such as genetics, hormonal agents and lifestyle characteristics. 6,7 Most importantly, breast density reduction has been shown to be a prognostic marker of response to adjuvant tamoxifen therapy in post-menopausal females.…”

Risk Factors for Stage IV Breast Cancer at the Time of Presentation in Turkey

“…MMG screening studies were conducted in Australia to reduce mortality from BC (Roder et al, 2008;Morrell et al, 2012). In another study, mortality due to BC was reduced by 26% in patients who were invited to a screening program for BC (Njor et al, 2012). In other related studies, MMG screening resulted in less DB-related mortality (van Schoor et al, 2011;Puliti and Zappa, 2012) and reduced BC by 15% compared to self-and clinical breast examinations in patients aged 39-69 years (Nelson et al, 2009).…”

Societal costs and effects of implementing population-based mammography screening in Greenland

“…A relative risk reduction (RRR) in breast cancer mortality of 20% in women invited to screening compared with non-invited control groups was found by a UK panel and Cochrane, both only including RCT-studies in their systematic review [6,9]. Two systematic reviews over incidence based studies estimated a 25–26% RRR [10,11], while a review of quasi-experimental studies found an effect of 16–23%, depending on the type of study design [8]. Consequently, the expected screening effect on breast cancer mortality is attached with uncertainty.…”