Systematic reviews as a “lens of evidence”: determinants of participation in breast cancer screening

OBJECTIVE: To assess determinants of the participation rate in breast cancer screening (BCS) programs by conducting a systematic review of reviews. METHODS: We conducted a systematic search in Pubmed via Medline, Scopus, Embase, and Cochrane identifying the literature up to April 2019. Out of 2,258 revealed unique abstracts, we included 31 reviews from which 25 were considered as systematic. We applied the Walsh & McPhee Systems Model of Clinical Preventive Care to systematise the determinants of screening participation. RESULTS: The reviews, mainly in high-income settings, reported a wide range for BCS participation rate: 16-90%. The determinants of BCS participation were simple low-cost interventions, such as invitation letters, basic information on screening, multiple reminders, fixed appointments, prompts from healthcare professionals, and healthcare organizational factors (eg. close proximity to screening facility). More complex interventions (such as face-to-face counselling or home visits), mass media or improved access to transport should not be encouraged by policy makers unless other information appears. The repeated participation in mammography screening was consistently high, above 62%. Previous positive experience with screening influenced the repeated participation in screening programs. The reviews were inconsistent in the use of terminology related to BCS participation, which may have contributed to the heterogeneity in the reported outcomes. CONCLUSIONS: This study shows that consistent findings of systematic reviews bring more certainty into the conclusions on effects of simple invitation techniques, fixed appointments and prompts, as well as healthcare organizational factors on promoting participation rate in screening mammography

What determines the effects and costs of breast cancer screening?

__Background:__ Multiple reviews demonstrated high variability in effectiveness and cost-effectiveness outcomes among studies on breast cancer screening (BCS) programmes. No study to our knowledge has summarized the current evidence on determinants of effectiveness and cost-effectiveness of the most used BCS approaches or tried to explain differences in conclusions of systematic reviews on this topic. Based on published reviews, this systematic review aims to assess the degree of variability of determinants for (a) effectiveness and (b) cost-effectiveness of BCS programmes using mammography, clinical breast examination, breast self-examination, ultrasonography, or their combinations among the general population. __Methods:__ We will perform a comprehensive systematic literature search in Cochrane, Scopus, Embase, and Medline (via Pubmed). The search will be supplemented with hand searching of references of the included reviews, with hand searching in the specialized journals, and by contacting prominent experts in the field. Additional search for grey literature will be conducted on the websites of international cancer associations and networks. Two trained research assistants will screen titles and abstracts of publications independently, with at least random 10% of all abstracts being also screened by the principal researcher. The full texts of the systematic reviews will then be screened independently by two authors, and disagreements will be solved by consensus. The included reviews will be grouped by publication year, outcomes, designs of original studies, and quality. Additionally, for reviews published since 2011, transparency in reporting will be assessed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist for the review on determinants of effectiveness and a modified PRISMA checklist for the review on determinants for cost-effectiveness. The study will apply the Assessing the Methodological Quality of Systematic Reviews checklist to assess the methodological quality of systematic reviews. We will report the data extracted from the systematic reviews in a systematic format. Meta-meta-analysis of extracted data will be conducted when feasible. __Discussion:__ This systematic review of reviews will examine the degree of variability in the effectiveness and cost-effectiveness of BCS programmes. _Systematic review registration:_ PROSPERO CRD42016050764and CRD42016050765

What determines the effects and costs of breast cancer screening?

__Background:__ Multiple reviews demonstrated high variability in effectiveness and cost-effectiveness outcomes among studies on breast cancer screening (BCS) programmes. No study to our knowledge has summarized the current evidence on determinants of effectiveness and cost-effectiveness of the most used BCS approaches or tried to explain differences in conclusions of systematic reviews on this topic. Based on published reviews, this systematic review aims to assess the degree of variability of determinants for (a) effectiveness and (b) cost-effectiveness of BCS programmes using mammography, clinical breast examination, breast self-examination, ultrasonography, or their combinations among the general population. __Methods:__ We will perform a comprehensive systematic literature search in Cochrane, Scopus, Embase, and Medline (via Pubmed). The search will be supplemented with hand searching of references of the included reviews, with hand searching in the specialized journals, and by contacting prominent experts in the field. Additional search for grey literature will be conducted on the websites of international cancer associations and networks. Two trained research assistants will screen titles and abstracts of publications independently, with at least random 10% of all abstracts being also screened by the principal researcher. The full texts of the systematic reviews will then be screened independently by two authors, and disagreements will be solved by consensus. The included reviews will be grouped by publication year, outcomes, designs of original studies, and quality. Additionally, for reviews published since 2011, transparency in reporting will be assessed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist for the review on determinants of effectiveness and a modified PRISMA checklist for the review on determinants for cost-effectiveness. The study will apply the Assessing the Methodological Quality of Systematic Reviews checklist to assess the methodological quality of systematic reviews. We will report the data extracted from the systematic reviews in a systematic format. Meta-meta-analysis of extracted data will be conducted when feasible. __Discussion:__ This systematic review of reviews will examine the degree of variability in the effectiveness and cost-effectiveness of BCS programmes. _Systematic review registration:_ PROSPERO CRD42016050764and CRD42016050765

Effect of organised cervical cancer screening on cervical cancer mortality in Europe: a systematic review

Background: Organised cervical cancer (CC) screening programmes are delivered in many different ways across the European Union and its regions. Our aim was to systematically review the impact of these programs on CC mortality. Methods: Two independent reviewers identified all eligible studies investigating the effect of organised screening on CC mortality in Europe. Six databases including Embase, Medline and Web of Science were searched (March 2018) with predefined inclusion and exclusion criteria. Only original studies with at least five years of follow-up were considered. Validated tools were used to assess the risk of bias of the included studies. Results: Ten observational studies were included: seven cohort and three case-control studies. No randomised controlled trials were found, and there were no eligible studies from the eastern and southern part of Europe. Among the eligible studies, seven were conducted in the twentieth century; they scored lower on the risk of bias assessment. CC mortality reduction for women attending organised screening vs. non-attenders ranged from 41% to 92% in seven studies. Reductions were similar in Western (45–92%) and Northern (41–8

Impact of colorectal cancer screening on cancer-specific mortality in Europe: A systematic review

Background: Populations differ with respect to their cancer risk and screening preferences, which may influence the performance of colorectal cancer (CRC) screening programs. This review aims to

Evidence for reducing cancer-specific mortality due to screening for breast cancer in Europe: A systematic review

Background: The aim of this study was to quantify the impact of organised mammography screening on breast cancer mortality across European regions. Therefore, a systematic review was performed including different types of studies from all European regions and stringently used clearly defined quality appraisal to summarise the best evidence. Methods: Six databases were searched including Embase, Medline and Web of Science from inception to March 2018. To identify all eligible studies which assessed the effect of organised screening on breast cancer mortality, two reviewers independently applied predefined inclusion and exclusion criteria. Original studies in English with a minimum follow-up of five years that were randomised controlled trials (RCTs) or observational studies were included. The Cochrane risk of bias instrument and the Newcastle–Ottawa Scale were used to assess the risk of bias. Results: Of the 5015 references initially retrieved, 60 were included in the final analysis. Those comprised 36 cohort studies, 17 case–control studies and 7 RCTs. None were from Eastern Europe. The quality of the included studies varied: Nineteen of these studies were of very good or good quality. Of those, the reduction in breast cancer mortality in attenders versus non-attenders ranged between 33% and 43% (Northern Europe), 43%–45% (Southern Europe) and 12%–58% (Western Europe). The estimates ranged between 4% and 31% in invited versus non-invited. Conclusion: This systematic review provides evidence that organised screening reduces breast cancer mortality in all European regions wh

Systematic reviews as a 'lens of evidence': Determinants of benefits and harms of breast cancer screening

This systematic review, stimulated by inconsistency in secondary evidence, reports the benefits and harms of breast cancer (BC) screening and their determinants according to systematic reviews. A systematic search, which identified 9,976 abstracts, led to the inclusion of 58 reviews. BC mortality reduction with screening mammography was 15–25% in trials and 28–56% in observational studies in all age groups, and the risk of stage III+ cancers was reduced for women older than 49 years. Overdiagnosis due to mammography was 1–60% in trials and 1–12% in studies with a low risk of bias, and cumulative falsepositive rates were lower with biennial than annual screening (3–17% vs 0.01–41%). There is no consistency in the reviews’ conclusions about the magnitude of BC mortality reduction among women younger than 50 years or older than 69 years, or determinants of benefits and harms of mammography, including the type of mammography (digital vs screen-film), the number of views and the screening interval. Similarly, there was no solid evidence on determinants of benefits and harms or BC mortality reduction with screening by ultrasonography or clinical breast examination (sensitivity ranges, 54–84% and 47–69%, respectively), and strong evidence of unfavourable benefit-to-harm ratio with breast self-examination. The reviews’ conclusions were not dependent on the quality of the reviews or publication date. Systematic reviews on mammography screening, mainly from high-income countries, systematically disagree on the interpretation of the benefit-to-harm ratio. Future reviews are unlikely to clarify the discrepancies unless new original studies are published

Effect of organised cervical cancer screening on cervical cancer mortality in Europe: a systematic review.

BACKGROUND: Organised cervical cancer (CC) screening programmes are delivered in many different ways across the European Union and its regions. Our aim was to systematically review the impact of these programs on CC mortality. METHODS: Two independent reviewers identified all eligible studies investigating the effect of organised screening on CC mortality in Europe. Six databases including Embase, Medline and Web of Science were searched (March 2018) with predefined inclusion and exclusion criteria. Only original studies with at least five years of follow-up were considered. Validated tools were used to assess the risk of bias of the included studies. RESULTS: Ten observational studies were included: seven cohort and three case-control studies. No randomised controlled trials were found, and there were no eligible studies from the eastern and southern part of Europe. Among the eligible studies, seven were conducted in the twentieth century; they scored lower on the risk of bias assessment. CC mortality reduction for women attending organised screening vs. non-attenders ranged from 41% to 92% in seven studies. Reductions were similar in Western (45-92%) and Northern (41-87%) Europe and were higher in the three more recent studies (66-92%). For invited vs. non-invited women, this reduction ranged from 17% to 79% in five studies. CONCLUSION: Although data were lacking in Southern and Eastern Europe and the effect size varied between countries and studies, this systematic review provides evidence that organised CC screening reduces CC mortality in those parts of Europe where CC screening was implemented and monitored

The potential of breast cancer screening in Europe.

Currently, all European countries offer some form of breast cancer screening. Nevertheless, disparities exist in the status of implementation, attendance and the extent of opportunistic screening. As a result, breast cancer screening has not yet reached its full potential. We examined how many breast cancer deaths could be prevented if all European countries would biennially screen all women aged 50 to 69 for breast cancer. We calculated the number of breast cancer deaths already prevented due to screening as well as the number of breast cancer deaths which could be additionally prevented if the total examination coverage (organised plus opportunistic) would reach 100%. The calculations are based on total examination coverage in women aged 50 to 69, the annual number of breast cancer deaths for women aged 50 to 74 and the maximal possible mortality reduction from breast cancer, assuming similar effectiveness of organised and opportunistic screening. The total examination coverage ranged from 49% (East), 62% (West), 64% (North) to 69% (South). Yearly 21 680 breast cancer deaths have already been prevented due to mammography screening. If all countries would reach 100% examination coverage, 12 434 additional breast cancer deaths could be prevented annually, with the biggest potential in Eastern Europe. With maximum coverage, 23% of their breast cancer deaths could be additionally prevented, while in Western Europe it could be 21%, in Southern Europe 15% and in Northern Europe 9%. Our study illustrates that by further optimising screening coverage, the number of breast cancer deaths in Europe can be lowered substantially