Worldwide Review and Meta-Analysis of Cohort Studies Measuring the Effect of Mammography Screening Programmes on Incidence-Based Breast Cancer Mortality

Abstract

In 2012, the Euroscreen project published a review of incidence-based mortality evaluations of breast cancer screening programmes. In this paper, we update this review to October 2019 and expand its scope from Europe to worldwide. We carried out a systematic review of incidence-based mortality studies of breast cancer screening programmes, and a meta-analysis of the estimated effects of both invitation to screening and attendance at screening, with adjustment for self-selection bias, on incidence-based mortality from breast cancer. We found 27 valid studies. The results of the meta-analysis showed a significant 22% reduction in breast cancer mortality with invitation to screening, with a relative risk of 0.78 (95% CI 0.75-0.82), and a significant 33% reduction with actual attendance at screening (RR 0.67, 95% CI 0.61-0.75). Breast cancer screening in the routine healthcare setting continues to confer a substantial reduction in mortality from breast cancer.

Keywords: breast cancer; incidence-based mortality; mammography; screening.

Figure 1

Literature search flow diagram.

Figure 2

Effect of invitation on risk of breast cancer mortality [14,18,20,23,24,25,28,30,32,33,36,38,41,47,48,49,52,53,54,55,56].

Figure 3

Estimated effect of attendance adjusted for self-selection on risk of breast cancer mortality ($R{R}_2$) [14,15,17,20,23,32,33,38,40,45,49,50,54].

Figure 4

Effect of invitation on risk of breast cancer mortality in women aged 50 and over [18,25,28,30,32,33,36,38,41,47,48,49,52,54,56].

Figure 5

Estimated effect of attendance adjusted for self-selection on risk of breast cancer mortality ($R{R}_2$) in women aged 50 and over [15,32,33,38,40,45,49,50,54].