The Impact of Mammographic Screening on Breast Cancer Mortality in Europe: A Review of Observational Studies

Abstract

Objectives To assess the impact of population-based mammographic screening on breast cancer mortality in Europe, considering different methodologies and limitations of the data. Methods We conducted a systematic literature review of European trend studies (n ¼ 17), incidencebased mortality (IBM) studies (n ¼ 20) and case-control (CC) studies (n ¼ 8). Estimates of the reduction in breast cancer mortality for women invited versus not invited and/or for women screened versus not screened were obtained. The results of IBM studies and CC studies were each pooled using a random effects meta-analysis. Results Twelve of the 17 trend studies quantified the impact of population-based screening on breast cancer mortality. The estimated breast cancer mortality reductions ranged from 1% to 9% per year in studies reporting an annual percentage change, and from 28% to 36% in those comparing post-and prescreening periods. In the IBM studies, the pooled mortality reduction was 25% (relative risk [RR] 0.75, 95% confidence interval [CI] 0.69 -0.81) among invited women and 38% (RR 0.62, 95% CI 0.56 -0.69) among those actually screened. The corresponding pooled estimates from the CC studies were 31% (odds ratio [OR] 0.69, 95% CI 0.57 -0.83), and 48% (OR 0.52, 95% CI 0.42 -0.65) adjusted for self-selection. Conclusions Valid observational designs are those where sufficient longitudinal individual data are available, directly linking a woman's screening history to her cause of death. From such studies, the best 'European' estimate of breast cancer mortality reduction is 25 -31% for women invited for screening, and 38 -48% for women actually screened. Much of the current controversy on breast cancer screening is due to the use of inappropriate methodological approaches that are unable to capture the true effect of mammographic screening.

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

“…The cumulated risk was adjusted for time of diagnosis, since women diagnosed with breast cancer before age 50 can inherently not benefit from a screening invitation after age 50. The RRR in breast cancer mortality because of invitation to mammography screening was assumed to be 20% on the basis of the literature search [6,8–11]. The absolute number of lives saved during a 10-year screening and follow-up period were estimated using the total number of women aged 50–69 years in Greenland from 2013.…”

“…The cost effectiveness of a breast cancer screening programme is influenced also by contextual factors in the healthcare system, the healthcare costs, the chosen screening interval, the chosen age interval of the women invited and the breast cancer epidemiology [7]. The magnitude of the effect of breast cancer screening is still disputed [8–11]. 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].…”

“…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.…”

Breast Cancer Screening Panels Continue to Confuse the Facts and Inject Their Own Biases

“…On the other hand, numerous studies show that screening results in declining deaths [14][15][16][17][18][19][27][28][29][30][31][32][33][34][35] , separate from access to therapy.…”

Is pain from mammography reduced by the use of a radiolucent MammoPad? Local experience in Hong Kong

“…1,2 Although most women are informed of the importance of mammography, a significant number avoid this screening procedure. The three most common reasons given are fear of pain, fear of the mammogram results, and fear of radiation.…”