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Contains fulltext : 292920.pdf (Publisher’s version ) (Open Access) Women tend to make a decision about participation in breast cancer screening and adhere to this for future invitations. Therefore, our study aimed to provide high-quality information on cumulative risks of false-positive (FP) recall and screen-detected breast cancer over multiple screening examinations. Individual Dutch screening registry data (2005-2018) were gathered on subsequent screening examinations of 92 902 women age 49 to 51 years in 2005. Survival analyses were used to calculate cumulative risks of a FP and a true-positive (TP) result after seven examinations. Data from 66 472 women age 58 to 59 years were used to extrapolate to 11 examinations. Participation, detection and additional FP rates were calculated for women who previously received FP results compared to women with true negative (TN) results. After 7 examinations, the cumulative risk of a TP result was 3.7% and the cumulative risk of a FP result was 9.1%. After 11 examinations, this increased to 7.1% and 13.5%, respectively. Following a FP result, participation was lower (71%-81%) than following a TN result (>90%). In women with a FP result, more TP results (factor 1.59 [95% CI: 1.44-1.72]), more interval cancers (factor 1.66 [95% CI: 1.41-1.91]) and more FP results (factor 1.96 [95% CI: 1.87-2.05]) were found than in women with TN results. In conclusion, due to a low recall rate in the Netherlands, the cumulative risk of a FP recall is relatively low, while the cumulative risk of a TP result is comparable. Breast cancer diagnoses and FP results were more common in women with FP results than in women with TN results, while participation was lower.

Background: Many European countries offer organised population-based breast, cervical, and colorectal cancer screening programmes. Around age 55 and 60, Dutch women are invited to all three screening programmes. We examined the extent to which participation concurs and identified factors influencing concurrent participation. Materials and methods: Individual level data from breast, cervical, and colorectal cancer screening invitations between 2017 and 2019 were extracted from the Dutch screening registry. The percentages of women participating in all three, two, one, or none of the programmes around age 55 and 60, and before subsequent round invitation were determined. Multivariate ordinal regression analyses were performed to estimate whether population density, socio-economic status (SES) per postal code area, and time between the three invitations (6 months) were associated with concurrent participation. Results: Data from 332,484 women were analysed. At age 55, 53.7% participated in all three programmes, 22.1% in two, 11.7% in one, and 12.6% did not participate at all. At age 60, a similar participation pattern was observed. Women living in areas with higher population density were less likely (odds ratios 0.75–0.94) and women in higher SES groups were more likely (odds ratios 1.12–1.60) to participate in more screening programmes, although this positive association was smaller for the highest SES group. No substantial association was found between concurrent participation and timing of invitations. Conclusions: More than half of Dutch women participated in all three screening programmes and around 12% did not participate in any. Concurrent participation was lower in cities and lower SES groups.

Objectives Organized breast cancer screening may not achieve its full potential due to organizational and cultural barriers. In Italy, two identified barriers were low attendance in Southern Italy and, in Italy as a whole, underscreening and overscreening in parts of the eligible population. The objective of this study was to identify potential changes to overcome these barriers and to quantify their costs and effects. Methods To assess the impact of potential measures to improve breast cancer screening in Italy, we performed an evaluation of costs and effects for increasing adherence for Southern Italy and harmonizing screening intervals (biennial screening) for the whole of Italy, using an online tool (EU-TOPIA evaluation tool) based on the MIcrosimulation SCreening ANalysis (MISCAN) model. Results Increasing adherence in Southern Italy through investing in mobile screening units has an acceptable cost-effectiveness ratio of €9531 per quality-adjusted life year gained. Harmonizing the screening interval by investing in measures to reduce opportunistic screening and simultaneously investing in mobile screening units to reduce underscreening is predicted to gain 1% fewer life-years, while saving 19% of total screening costs compared to the current situation. Conclusions Increasing adherence in Southern Italy and harmonizing the screening interval could result in substantial improvements at acceptable costs, or in the same benefits at lower costs. This example illustrates a systematic approach that can be easily applied to other European countries, as the online tools can be used by stakeholders to quantify effects and costs of a broad range of specific barriers, and ways to overcome them.

Purpose Normative utility scores represent the health related quality of life of the general population, are of utmost importance in cost-effectiveness studies and should reflect relevant sexes and age groups. The aim of this study was to estimate EQ-5D-5L normative utility scores in a population of Dutch females, stratified by age, and to compare these scores to those of female populations of three other countries. Methods Dutch women completed the EQ-5D-5L online between January and July 2020. Mean normative utilities were computed using the Dutch EQ-5D-5L value set, stratified by age, tested for differences using the Kruskall–Wallis test, and compared to normative utility scores of female populations elsewhere. Additionally, to support the use of the Dutch EQ-5D-5L data in other settings, normative utility scores were also calculated by applying the value sets of Germany, United Kingdom and USA. Results Data of 9037 women were analyzed and the weighted mean utility score was 0.911 (SD 0.155, 95% CI 0.908–0.914). The mean normative utility scores differed between age groups, showing lower scores in older females. Compared to other normative utility scores of female populations, Dutch mean utilities were consistently higher except for age groups 18–24 and 25–34. With the three country-specific value sets, new age-specific mean normative utility scores were provided. Conclusion This study provides mean normative utility scores of a large cohort of Dutch females per age group, which were found to be lower in older age groups. Utility scores calculated with three other value sets were made available.

Background A paucity of research addresses breast cancer screening strategies for women at lower-than-average breast cancer risk. The aim of this study was to examine screening harms and benefits among women aged 50-74 years at lower-than-average breast cancer risk by breast density. Methods Three well-established, validated Cancer Intervention and Surveillance Network models were used to estimate the lifetime benefits and harms of different screening scenarios, varying by screening interval (biennial, triennial). Breast cancer deaths averted, life-years and quality-adjusted life-years gained, false-positives, benign biopsies, and overdiagnosis were assessed by relative risk (RR) level (0.6, 0.7, 0.85, 1 [average risk]) and breast density category, for US women born in 1970. Results Screening benefits decreased proportionally with decreasing risk and with lower breast density. False-positives, unnecessary biopsies, and the percentage overdiagnosis also varied substantially by breast density category; false-positives and unnecessary biopsies were highest in the heterogeneously dense category. For women with fatty or scattered fibroglandular breast density and a relative risk of no more than 0.85, the additional deaths averted and life-years gained were small with biennial vs triennial screening. For these groups, undergoing 4 additional screens (screening biennially [13 screens] vs triennially [9 screens]) averted no more than 1 additional breast cancer death and gained no more than 16 life-years and no more than 10 quality-adjusted life-years per 1000 women but resulted in up to 232 more false-positives per 1000 women. Conclusion Triennial screening from age 50 to 74 years may be a reasonable screening strategy for women with lower-than-average breast cancer risk and fatty or scattered fibroglandular breast density.

OBJECTIVES: Value of information (VOI) analysis can support health technology assessment decision making, but it is a long way from being standard use. The objective of this study was to understand barriers to the implementation of VOI analysis and propose actions to overcome these.METHODS: We performed a process evaluation of VOI analysis use within decision making on tomosynthesis versus digital mammography for use in the Dutch breast cancer population screening. Based on steering committee meeting attendance and regular meetings with analysts, we developed a list of barriers to VOI use, which were analyzed using an established diffusion model. We proposed actions to address these barriers. Barriers and actions were discussed and validated in a workshop with stakeholders representing patients, clinicians, regulators, policy advisors, researchers, and the industry.RESULTS: Consensus was reached on groups of barriers, which included characteristics of VOI analysis itself, stakeholder's attitudes, analysts' and policy makers' skills and knowledge, system readiness, and implementation in the organization. Observed barriers did not only pertain to VOI analysis itself but also to formulating the objective of the assessment, economic modeling, and broader aspects of uncertainty assessment. Actions to overcome these barriers related to organizational changes, knowledge transfer, cultural change, and tools.CONCLUSIONS: This in-depth analysis of barriers to implementation of VOI analysis and resulting actions and tools may be useful to health technology assessment organizations that wish to implement VOI analysis in technology assessment and research prioritization. Further research should focus on application and evaluation of the proposed actions in real-world assessment processes.

Breast cancer screening is associated with harms, such as false-positives and overdiagnoses, and, thus, novel screen tests can be considered. Liquid biopsies have been proposed as a novel method for the early detection of cancer, but low cell-free DNA tumor fraction might pose a problem for the use in population screening. Using breast cancer microsimulation model MISCAN-Fadia, we estimated the outcomes of using liquid biopsies in breast cancer screening in women aged 50 to 74 in the United States. For varying combinations of test sensitivity and specificity, we quantify the impact of the use of liquid biopsies on the harms and benefits of screening, and we estimate the maximum liquid biopsy price for cost-effective implementation in breast cancer screening at a cost-effectiveness threshold of USD 50,000. We investigate under what conditions liquid biopsies could be a suitable alternative to digital mammography and compare these conditions to a CCGA substudy. Outcomes were compared to digital mammography screening, and include mortality reduction, overdiagnoses, quality-adjusted life-years (QALYs), and the maximum price of a liquid biopsy for cost-effective implementation. When liquid biopsies are unable to detect DCIS, a large proportion of overdiagnosed cases is prevented but overall breast cancer mortality reduction and quality of life are lower, and costs are higher compared to digital mammography screening. Liquid biopsies prices should be restricted to USD 187 per liquid biopsy depending on test performance. Overall, liquid biopsies that are unable to detect ductal carcinoma in situ (DCIS) need to be able to detect small, early-stage tumors, with high specificity, at low costs in order to be an alternative to digital mammography. Liquid biopsies might be more suitable as an addition to digital mammography than as an alternative.

Background We assessed the clinical utility of a first-degree breast cancer family history and polygenic risk score (PRS) to inform screening decisions among women aged 30-50 years. Methods Two established breast cancer models evaluated digital mammography screening strategies in the 1985 US birth cohort by risk groups defined by family history and PRS based on 313 single nucleotide polymorphisms. Strategies varied in initiation age (30, 35, 40, 45, and 50 years) and interval (annual, hybrid, biennial, triennial). The benefits (breast cancer deaths averted, life-years gained) and harms (false-positive mammograms, overdiagnoses) were compared with those seen with 3 established screening guidelines. Results Women with a breast cancer family history who initiated biennial screening at age 40 years (vs 50 years) had a 36% (model range = 29%-40%) increase in life-years gained and 20% (model range = 16%-24%) more breast cancer deaths averted, but 21% (model range = 17%-23%) more overdiagnoses and 63% (model range = 62%-64%) more false positives. Screening tailored to PRS vs biennial screening from 50 to 74 years had smaller positive effects on life-years gained (20%) and breast cancer deaths averted (11%) but also smaller increases in overdiagnoses (10%) and false positives (26%). Combined use of family history and PRS vs biennial screening from 50 to 74 years had the greatest increase in life-years gained (29%) and breast cancer deaths averted (18%). Conclusions Our results suggest that breast cancer family history and PRS could guide screening decisions before age 50 years among women at increased risk for breast cancer but expected increases in overdiagnoses and false positives should be expected.

Background: Limited research is available on the cost-effectiveness of breast cancer screening programs in Asian countries. We evaluated the cost-effectiveness of Singapore's national mammography screening program, implemented in 2002, recommending annual screening between ages 40 and 49 and biennial screening between ages 50 and 69, and alternative screening scenarios taking into account important country-specific factors. Methods: We used national data from Singapore in the MIcrosimulation SCreening ANalysis-Fatal diameter (MISCAN-Fadia) model to simulate 302 screening scenarios for 10 million women born between 1910 and 1969. Screening scenarios varied by starting and ending age, screening interval, and attendance. Outcome measures included life-years gained (LYG), breast cancer deaths averted, false positives, overdiagnosis, quality-adjusted life years (QALY), costs (in 2002 Singapore dollars; S$), and incremental cost-effectiveness ratios (ICER). Costs and effects were calculated and discounted with 3% using a health care provider's perspective. Results: Singapore's current screening program at observed attendance levels required 54,158 mammograms per 100,000 women, yielded 1,054 LYG, and averted 57 breast cancer deaths. At attendance rates ≥50%, the current program was near the efficiency frontier. Most scenarios on the efficiency frontier started screening at age 40. The ICERs of the scenarios on the efficiency frontiers ranged between S$10,186 and S$56,306/QALY, which is considered cost-effective at a willingness-to-pay threshold of S$70,000/QALY gained. Conclusions: Singapore's current screening program lies near the efficiency frontier, and starting screening at age 40 or 45 is cost-effective. Furthermore, enhancing screening attendance rates would increase benefits while maintaining cost-effectiveness. Impact: Screening all women at age 40 or 45 is cost-efficient in Singapore, and a policy change may be considered.

Background: Digital breast tomosynthesis (DBT) is a promising screening test, but its outcomes and cost-effectiveness remain uncertain.Purpose: To determine if biennial DBT is cost-effective in a screening setting, when compared with digital mammography (DM) in the Netherlands, and to quantify the uncertainty.Materials and Methods: In this study, performed from March 2018 to February 2019, the MIcrosimulation SCreening ANalysis model was used to conduct a probabilistic sensitivity analysis (PSA), consisting of 10 000 model runs with 1 000 000 women simulated per run. The Bayesian Cost-Effectiveness Analysis package and the Sheffield Accelerated Value of Information tool were used to process PSA outcomes. Two simulated cohorts born in 1970 were invited to undergo biennial screening between ages 50 and 74 years-one cohort was assigned to DM screening, and one was assigned to DBT screening. DM input parameters were based on data from the Dutch breast cancer screening program. DBT parameters were based on literature and expert opinion. Willingness-to-pay thresholds of 20000 ($22 000) and C35000 ($38500) per life-year gained (LYG) were considered. Effects and costs were discounted at 3.5% per year.Results: DBT resulted in a gain of 13 additional life-years per 1000 women invited to screening (7% increase, 13 of 193), followed over lifetime, compared with DM and led to 2% (four of 159) fewer false-positive results. DBT screening led to incremental discounted lifetime effects of 5.09 LYGs (95% confidence interval: -0.80, 9.70) and an increase in lifetime costs of (sic)137 555 ($151 311) per 1000 women (95% confidence interval: (sic)31 093 [$34 202], (sic)263 537 [$289 891]) compared with DM, resulting in a mean incremental cost-effectiveness ratio of (sic)27 023 ($29 725) per LYG. The probability of DBT being more cost-effective was 0.36 at (sic)20 000 and 0.66 at (sic)35 000 per LYG.Conclusion: Switching from digital mammography to biennial digital breast tomosynthesis is not cost-effective at a willingness-to-pay threshold of (sic)20 000 per life-year gained, but digital breast tomosynthesis has a higher probability of being more cost-effective than digital mammography at a threshold of (sic)35 000 per life-year gained. (C) RSNA, 2020

Background Extremely dense breast tissue is associated with increased breast cancer risk and limited sensitivity of mammography. The DENSE trial showed that additional magnetic resonance imaging (MRI) screening in women with extremely dense breasts resulted in a substantial reduction in interval cancers. The cost-effectiveness of MRI screening for these women is unknown. Methods We used the MISCAN-breast microsimulation model to simulate several screening protocols containing mammography and/or MRI to estimate long-term effects and costs. The model was calibrated using results of the DENSE trial and adjusted to incorporate decreases in breast density with increasing age. Screening strategies varied in the number of MRIs and mammograms offered to women ages 50-75 years. Outcomes were numbers of breast cancers, life-years, quality-adjusted life-years (QALYs), breast cancer deaths, and overdiagnosis. Incremental cost-effectiveness ratios (ICERs) were calculated (3% discounting), with a willingness-to-pay threshold of €22 000. Results Calibration resulted in a conservative fit of the model regarding MRI detection. Both strategies of the DENSE trial were dominated (biennial mammography; biennial mammography plus MRI). MRI alone every 4 years was cost-effective with €15 620 per QALY. Screening every 3 years with MRI alone resulted in an incremental cost-effectiveness ratio of €37 181 per QALY. All strategies with mammography and/or a 2-year interval were dominated because other strategies resulted in more additional QALYs per additional euro. Alternating mammography and MRI every 2 years was close to the efficiency frontier. Conclusions MRI screening is cost-effective for women with extremely dense breasts, when applied at a 4-year interval. For a willingness to pay more than €22 000 per QALY gained, MRI at a 3-year interval is cost-effective as well.

The COVID-19 pandemic affects mortality and morbidity, with disruptions expected to continue for some time, with access to timely cancer-related services a concern. For breast cancer, early detection and treatment is key to improved survival and longer-term quality of life. Health services generally have been strained and in many settings with population breast mammography screening, efforts to diagnose and treat breast cancers earlier have been paused or have had reduced capacity. The resulting delays to diagnosis and treatment may lead to more intensive treatment requirements and, potentially, increased mortality. Modelled evaluations can support responses to the pandemic by estimating short- and long-term outcomes for various scenarios. Multiple calibrated and validated models exist for breast cancer screening, and some have been applied in 2020 to estimate the impact of breast screening disruptions and compare options for recovery, in a range of international settings. On behalf of the Covid and Cancer Modelling Consortium (CCGMC) Working Group 2 (Breast Cancer), we summarize and provide examples of such in a range of settings internationally, and propose priorities for future modelling exercises. International expert collaborations from the CCGMC Working Group 2 (Breast Cancer) will conduct analyses and modelling studies needed to inform key stakeholders recovery efforts in order to mitigate the impact of the pandemic on early diagnosis and treatment of breast cancer.

Background Aiming to support European countries in improving their breast, cervical, and colorectal cancer (CRC) screening programmes, the EU-TOPIA consortium has developed an online user-friendly tool (the EU-TOPIA evaluation tool; https://miscan.eu-topia.org ) based on the Microsimulation Screening Analysis (MISCAN) model. Methods We designed an online platform that allows stakeholders to use their country-specific data (demographic, epidemiological, and cancer screening information) to quantify future harms and benefits of different cancer screening scenarios in their country. Current cancer screening programmes and impacts of potential changes in screening protocols (such as extending target ages or increasing screening attendance) can be simulated. Results are scaled to the country-specific population. To illustrate the tool, we used the tool to simulate two different CRC screening scenarios in the Netherlands: biennial fecal immunochemical testing (FIT) in ages 55–75 and colonoscopy every ten years in ages 55–75. Data from the Dutch screening programme was used to inform both scenarios. Results A total of 482,700 CRC cases and 178,000 CRC deaths were estimated in the Netherlands with FIT screening (for individuals aged 40–100 years, 2018–2050), with 47.3 million FITs performed (1.92 million positives of which 1.64 million adhered to diagnostic colonoscopy). With colonoscopy screening, CRC incidence and mortality were, respectively, up to 17% and 14% lower than in the current FIT screening programme, requiring, however, a colonoscopy demand that was 7-fold higher. Conclusions Our study presents an essential online tool for stakeholders and medical societies to quantify estimates of benefits and harms of early cancer detection in Europe.

Women with Down syndrome have a lower breast cancer risk and significantly lower life expectancies than women without Down syndrome. Therefore, it is not clear whether mammography screening strategies used for women without Down syndrome would benefit women with Down syndrome in the same way. To determine the benefits and harms of various mammography screening strategies for women with Down syndrome using collaborative simulation modeling. Two established Cancer Intervention and Surveillance Modeling Network (CISNET) simulation models estimated the benefits and harms of various screening strategies for women with Down syndrome over a lifetime horizon. We modeled a hypothetical cohort of US women with Down syndrome who were born in 1970. Annual, biennial, triennial, and one-time digital mammography screenings during the ages 40–74. The models estimated numbers of mammograms, false-positives, benign biopsies, breast cancer deaths prevented, and life-years gained per 1000 screened women when compared with no screening. In average-risk women 50–74, biennial screening incurred 122 mammograms, 10 false-positive mammograms, and 1.4 benign biopsies per one life-year gained compared with no screening. In women with Down syndrome, the same screening strategy incurred 2752 mammograms, 242 false-positive mammograms, and 34 benign biopsies per one life-year gained compared with no screening. The harm/benefit ratio varied for other screening strategies, and was most favorable for one-time screening at age 50, which incurred 1629 mammograms, 144 false-positive mammograms, and 20 benign biopsies per one life-year gained compared with no screening. The harm/benefit ratios for various mammography screening strategies in women with Down syndrome are not as favorable as those for average-risk women. The benefit of screening mammography for women with Down syndrome is less pronounced due to lower breast cancer risk and shorter life expectancy.

Simple Summary Breast cancer screening causes harms and benefits. The balance between the two varies by age. By applying microsimulation modelling, we compared several age ranges of screening in four European countries (the Netherlands, Finland, Italy and Slovenia) and evaluated the respective harm-to-benefit ratios. In all countries, adding screening between the ages 45 and 49 or 70 and 74 resulted in more life-years gained and more breast cancer deaths averted, but at the expense of increases in harms. Adapting the age range of breast cancer screening is an option to improve harm-to-benefit ratios in all four countries. The prioritization of considered harms and benefits affects the interpretation of results. Abstract The main benefit of breast cancer (BC) screening is a reduction in mortality from BC. However, screening also causes harms such as overdiagnosis and false-positive results. The balance between benefits and harms varies by age. This study aims to assess how harm-to-benefit ratios of BC screening vary by age in the Netherlands, Finland, Italy and Slovenia. Using microsimulation models, we simulated biennial screening with 100% attendance at varying ages for cohorts of women followed over a lifetime. The number of overdiagnoses, false-positive diagnoses, BC deaths averted and life-years gained (LYG) were calculated per 1000 women. We compared four strategies (50–69, 45–69, 45–74 and 50–74) by calculating four harm-to-benefit ratios, respectively. Compared to the reference strategy 50–69, screening women at 45–74 or 50–74 years would be less beneficial in any of the four countries than screening women at 45–69, which would result in relatively fewer overdiagnoses per death averted or LYG. At the same time, false-positive results per death averted would increase substantially. Adapting the age range of BC screening is an option to improve harm-to-benefit ratios in all four countries. Prioritization of considered harms and benefits affects the interpretation of results.

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., What's new? Breast cancer is the leading cause of death among European women. Although screening for breast cancer is available in all European countries, not all eligible women aged 50‐69 get screened. Here, the authors calculated how many deaths could be prevented if screening coverage reached 100%, considering both organized and opportunistic screening. Already, screening prevents 21 680 deaths per year, and if all countries reached full examination coverage, an additional 12 434 deaths per year could be prevented across Europe.

Background. Collaborative modeling has been used to estimate the impact of potential cancer screening strategies worldwide. A necessary step in the interpretation of collaborative cancer screening model results is to understand how model structure and model assumptions influence cancer incidence and mortality predictions. In this study, we examined the relative contributions of the pre-clinical duration of breast cancer, the sensitivity of screening, and the improvement in prognosis associated with treatment of screen-detected cases to the breast cancer incidence and mortality predictions of 5 Cancer Intervention and Surveillance Modeling Network (CISNET) models. Methods. To tease out the impact of model structure and assumptions on model predictions, the Maximum Clinical Incidence Reduction (MCLIR) method compares changes in the number of breast cancers diagnosed due to clinical symptoms and cancer mortality between 4 simplified scenarios: 1) no-screening; 2) one-time perfect screening exam, which detects all existing cancers and perfect treatment (i.e., cure) of all screen-detected cancers; 3) one-time digital mammogram and perfect treatment of all screen-detected cancers; and 4) one-time digital mammogram and current guideline-concordant treatment of all screen-detected cancers. Results. The 5 models predicted a large range in maximum clinical incidence (19% to 71%) and in breast cancer mortality reduction (33% to 67%) from a one-time perfect screening test and perfect treatment. In this perfect scenario, the models with assumptions of tumor inception before it is first detectable by mammography predicted substantially higher incidence and mortality reductions than models with assumptions of tumor onset at the start of a cancer’s screen-detectable phase. The range across models in breast cancer clinical incidence (11% to 24%) and mortality reduction (8% to 18%) from a one-time digital mammogram at age 62 y with observed sensitivity and current guideline-concordant treatment was considerably smaller than achievable under perfect conditions. Conclusions. The timing of tumor inception and its effect on the length of the pre-clinical phase of breast cancer had a substantial impact on the grouping of models based on their predictions for clinical incidence and breast cancer mortality reduction. This key finding about the timing of tumor inception will be included in future CISNET breast analyses to enhance model transparency. The MCLIR approach should aid in the interpretation of variations in model results and could be adopted in other disease screening settings to enhance model transparency.

The MISCAN-Fadia microsimulation model uses continuous tumor growth to simulate the natural history of breast cancer and has been used extensively to estimate the impact of screening and adjuvant treatment on breast cancer incidence and mortality trends. The model simulates individual life histories from birth to death, with and without breast cancer, in the presence and in the absence of screening and treatment. Life histories are simulated according to discrete events such as birth, tumor inception, the tumor’s clinical diagnosis diameter in the absence of screening, and death from breast cancer or death from other causes. MISCAN-Fadia consists of 4 main components: demography, natural history of breast cancer, screening, and treatment. Screening impact on the natural history of breast cancer is assessed by simulating continuous tumor growth and the “fatal diameter” concept. This concept implies that tumors diagnosed at a size that is between the screen detection threshold and the fatal diameter are cured, while tumors diagnosed at a diameter larger than the fatal tumor diameter metastasize and lead to breast cancer death. MISCAN-Fadia has been extended by including a different natural history for molecular subtypes based on a tumor’s estrogen receptor (ER) status and human epidermal growth factor receptor 2 (HER2) status. In addition, personalized screening strategies that target women based on their risk such as breast density have been incorporated into the model. This personalized approach to screening will continue to develop in light of potential polygenic risk stratification possibilities and new screening modalities.

The benefits of population-based screening for breast cancer are now accepted although, in practice, programmes often fail to achieve their full potential. In this paper, we propose a conceptual model that situates screening programmes within the broader health system to understand the factors that influence their outcomes. We view the overall screening system as having multiple sub-systems to identify the population at risk, generate knowledge of effectiveness, maximise uptake, operate the programme, and optimise follow-up and assurance of subsequent treatment. Based on this model we have developed the Barriers to Effective Screening Tool (BEST) for analysing government-led, population-based screening programmes from a health systems perspective. Conceived as a self-assessment tool, we piloted the tool with key informants in six European countries (Estonia, Finland, Hungary, Italy, The Netherlands and Slovenia) to identify barriers to the optimal operation of population-based breast cancer screening programmes. The pilot provided valuable feedback on the barriers affecting breast cancer screening programmes and stimulated a greater recognition among those operating them of the need to take a health systems perspective. In addition, the pilot led to further development of the tool and provided a foundation for further research into how to overcome the identified barriers.

Background. The UK Age trial compared annual mammography screening of women ages 40 to 49 years with no screening and found a statistically significant breast cancer mortality reduction at the 10-year follow-up but not at the 17-year follow-up. The objective of this study was to compare the observed Age trial results with the Cancer Intervention and Surveillance Modeling Network (CISNET) breast cancer model predicted results. Methods. Five established CISNET breast cancer models used data on population demographics, screening attendance, and mammography performance from the Age trial together with extant natural history parameters to project breast cancer incidence and mortality in the control and intervention arm of the trial. Results. The models closely reproduced the effect of annual screening from ages 40 to 49 years on breast cancer incidence. Restricted to breast cancer deaths originating from cancers diagnosed during the intervention phase, the models estimated an average 15% (range across models, 13% to 17%) breast cancer mortality reduction at the 10-year follow-up compared with 25% (95% CI, 3% to 42%) observed in the trial. At the 17-year follow-up, the models predicted 13% (range, 10% to 17%) reduction in breast cancer mortality compared with the non-significant 12% (95% CI, -4% to 26%) in the trial. Conclusions. The models underestimated the effect of screening on breast cancer mortality at the 10-year follow-up. Overall, the models captured the observed long-term effect of screening from age 40 to 49 years on breast cancer incidence and mortality in the UK Age trial, suggesting that the model structures, input parameters, and assumptions about breast cancer natural history are reasonable for estimating the impact of screening on mortality in this age group.

Importance: In 2018, only half of US women obtained all evidence-based cancer screenings. This proportion may have declined during the COVID-19 pandemic because of social distancing, high-risk factors, and fear.Objective: To evaluate optimal screening strategies in women who obtain some, but not all, US Preventive Services Task Force (USPSTF)-recommended cancer screenings.Design, Setting, and Participants: This modeling study was conducted from January 31, 2017, to July 20, 2020, and used 4 validated mathematical models from the National Cancer Institute's Cancer Intervention and Surveillance Modeling Network using data from 20 million simulated women born in 1965 in the US.Interventions: Forty-five screening strategies were modeled that combined breast, cervical, colorectal, and/or lung cancer (LC) screenings; restricted to 1, 2, 3 or 4 screenings per year; or all eligible screenings once every 5 years.Main Outcomes and Measures: Modeled life-years gained from restricted cancer screenings as a fraction of those attainable from full compliance with USPSTF recommendations (maximum benefits). Results were stratified by LC screening eligibility (LC-eligible/ineligible). We repeated the analysis with 2018 adherence rates, evaluating the increase in adherence required for restricted screenings to have the same population benefit as USPSTF recommendations.Results: This modeling study of 20 million simulated US women found that it was possible to reduce screening intensity to 1 carefully chosen test per year in women who were ineligible for LC screening and 2 tests per year in eligible women while maintaining 94% or more of the maximum benefits. Highly ranked strategies screened for various cancers, but less often than recommended by the USPSTF. For example, among LC-ineligible women who obtained just 1 screening per year, the optimal strategy frequently delayed breast and cervical cancer screenings by 1 year and skipped 3 mammograms entirely. Among LC-eligible women, LC screening was essential; strategies omitting it provided 25% or less of the maximum benefits. The top-ranked strategy restricted to 2 screenings per year was annual LC screening and alternating fecal immunochemical test with mammography (skipping mammograms when due for cervical cancer screening, 97% of maximum benefits). If adherence in a population of LC-eligible women obtaining 2 screenings per year were to increase by 1% to 2% (depending on the screening test), this model suggests that it would achieve the same benefit as USPSTF recommendations at 2018 adherence rates.Conclusions and Relevance: This modeling study of 45 cancer screening strategies suggests that women who are noncompliant with cancer screening guidelines may be able to reduce USPSTF-recommended screening intensity with minimal reduction in overall benefits.

Long-term follow-up data on the effects of screening are scarce, and debate exists on the relative contribution of screening versus treatment to breast cancer mortality reduction. Our aim was therefore to assess the long-term effect of screening by age and time of implementation. We obtained data on 69,630 breast cancer deaths between 1980 and 2010 by municipality (N = 431) and age of death (40-79) in the Netherlands. Breast cancer mortality trends were analyzed by defining the municipality-specific calendar year of introduction of screening as Year 0. Additionally, log-linear Poisson regression was used to estimate the turning point in the trend after Year 0, per municipality, and the annual percentage change (APC) before and after this point. Twenty years after introduction of screening breast cancer mortality was reduced by 30% in women aged 55-74 and by 34% in women aged 75-79, compared to Year 0. A similar and significant decrease was present in municipalities that started early (1987-1992) and late (1995-1997) with screening, despite the difference in availability of effective adjuvant treatment. In the age groups 55-74 and 75-79, the turning point in the trend in breast cancer mortality was estimated in Years 2 and 6 after the introduction of screening, respectively, after which mortality decreased significantly by 1.9% and 2.6% annually. These findings show that the implementation of mammography screening in Dutch municipalities is associated with a significant decline in breast cancer mortality in women aged 55-79, irrespective of time of implementation.

To assess the effect of an information leaflet on knowledge, explicit attitudes, implicit associations, and attendance for breast cancer screening.Dutch women (aged 49-75 years) were approached three months before their breast cancer screening invitation. After providing informed consent, participants were randomised to receiving the information leaflet (intervention condition) or not (control condition). Screening knowledge, explicit attitudes, and implicit associations were assessed through web-based questionnaires, at baseline and two weeks later. Actual screening attendance data were collected.In total, 988 women completed both questionnaires. Participants in the leaflet condition scored higher on knowledge (9.9 versus 9.6, p 0.001, scale 0-11), and more often had positive explicit attitudes (97 % versus 95 %, p = 0.03), than those in the control condition. This contrast was bigger among first-time invitees. Implicit associations were not correlated with explicit attitudes or attendance. Explicit attitudes were moderately correlated with attendance (r=.30, p 0.001).The information leaflet led to more knowledge and more positive explicit attitudes. Implicit associations towards breast cancer screening were not correlated with attendance.Encouragement to learn about the screening programme can increase levels of knowledge of invitees and therefore support their decision-making about participation. This might be especially relevant for first-time invitees.

In mammography screening programmes, women are screened according to a one-size-fits-all principle. Tailored screening, based on risk levels, may lead to a better balance of benefits and harms. With microsimulation modelling, we determined optimal mammography screening strategies for women at lower (relative risk [RR] 0.75) and higher (RR 1.8) than average risk of breast cancer, eligible for screening, using the incremental cost-effectiveness ratio (ICER) of current uniform screening in the Netherlands (biennial [B] 50-74) as a threshold ICER. Strategies varied by interval (annual [A], biennial, triennial [T]) and age range. The number of life-years gained (LYG), breast cancer deaths averted, overdiagnosed cases, false-positive mammograms, ICERs and harm-benefit ratios were calculated. Optimal risk-based screening scenarios, below the threshold ICER of €8883/LYG, were T50-71 (€7840/LYG) for low-risk and B40-74 (€6062/LYG) for high-risk women. T50-71 screening in low-risk women resulted in a 33% reduction in false-positive findings, a similar reduction in costs and improved harm-benefit ratios compared to the current screening schedule. B40-74 in high-risk women led to an increase in screening benefit, compared to current B50-74 screening, but a relatively higher increase in false-positive findings. In conclusion, optimal screening consisted of a longer interval and lower stopping age than current uniform screening for low-risk women, and a lower starting age for high-risk women. Extending the interval for women at lower risk from biennial to triennial screening reduced harms and costs while maintaining most of the screening benefit.

10500 Background: Inherited pathogenic variants in ATM, CHEK2, and PALB2 confer moderate to high risks of breast cancer. The optimal approach to screening in these women has not been established. Methods: We used two simulation models from the Cancer Intervention and Surveillance Modeling Network (CISNET) and data from the Cancer Risk Estimates Related to Susceptibility consortium (CARRIERS) to project lifetime breast cancer incidence and mortality in ATM, CHEK2, and PALB2 carriers. We simulated screening with annual mammography from ages 40-74 alone and with annual magnetic resonance imaging (MRI) starting at ages 40, 35, 30, and 25. Joint and separate mammography and MRI screening performance was based on published literature. Lifetime outcomes per 1,000 women were reported as means and ranges across both models. Results: Estimated risk of breast cancer by age 80 was 22% (21-23%) for ATM, 28% (26-30%) for CHEK2, and 40% (38-42%) for PALB2. Screening with MRI and mammography reduced breast cancer mortality by 52-60% across variants (Table). Compared to no screening, starting MRI at age 30 increased life years (LY)/1000 women by 501 (478-523) in ATM, 620 (587-652) in CHEK2, and 1,025 (998-1,051) in PALB2. Starting MRI at age 25 versus 30 gained 9-12 LY/1000 women with 517-518 additional false positive screens and 197-198 benign biopsies. Conclusions: For women with ATM, CHEK2, and PALB2 pathogenic variants, breast cancer screening with MRI and mammography halves breast cancer mortality. These mortality benefits are similar to those for MRI screening for BRCA1/2 mutation carriers and should inform practice guidelines.[Table: see text]

Background. Ductal carcinoma in situ (DCIS) can be a precursor to invasive breast cancer. Since the advent of screening mammography in the 1980’s, the incidence of DCIS has increased dramatically. The value of screen detection and treatment of DCIS, however, is a matter of controversy, as it is unclear the extent to which detection and treatment of DCIS prevents invasive disease and reduces breast cancer mortality. The aim of this paper is to provide an overview of existing Cancer Intervention and Surveillance Modelling Network (CISNET) modeling approaches for the natural history of DCIS, and to compare these to other modeling approaches reported in the literature. Design. Five of the 6 CISNET models currently include DCIS. Most models assume that some, but not all, lesions progress to invasive cancer. The natural history of DCIS cannot be directly observed and the CISNET models differ in their assumptions and in the data sources used to estimate the DCIS model parameters. Results. These model differences translate into variation in outcomes, such as the amount of overdiagnosis of DCIS, with estimates ranging from 34% to 72% for biennial screening from ages 50 to 74 y. The other models described in the literature also report a large range in outcomes, with progression rates varying from 20% to 91%. Limitations. DCIS grade was not yet included in the CISNET models. Conclusion. In the future, DCIS data by grade from active surveillance trials, the development of predictive markers of progression probability, and evidence from other screening modalities, such as tomosynthesis, may be used to inform and improve the models’ representation of DCIS, and might lead to convergence of the model estimates. Until then, the CISNET model results consistently show a considerable amount of overdiagnosis of DCIS, supporting the safety and value of observational trials for low-risk DCIS.

Importance Given recent advances in screening mammography and adjuvant therapy (treatment), quantifying their separate and combined effects on US breast cancer mortality reductions by molecular subtype could guide future decisions to reduce disease burden. Objective To evaluate the contributions associated with screening and treatment to breast cancer mortality reductions by molecular subtype based on estrogen-receptor (ER) and human epidermal growth factor receptor 2 ( ERBB2 , formerly HER2 or HER2/neu ). Design, Setting, and Participants Six Cancer Intervention and Surveillance Network (CISNET) models simulated US breast cancer mortality from 2000 to 2012 using national data on plain-film and digital mammography patterns and performance, dissemination and efficacy of ER /ERBB2 -specific treatment, and competing mortality. Multiple US birth cohorts were simulated. Exposures Screening mammography and treatment. Main Outcomes and Measures The models compared age-adjusted, overall, and ER /ERBB2 -specific breast cancer mortality rates from 2000 to 2012 for women aged 30 to 79 years relative to the estimated mortality rate in the absence of screening and treatment (baseline rate); mortality reductions were apportioned to screening and treatment. Results In 2000, the estimated reduction in overall breast cancer mortality rate was 37% (model range, 27%-42%) relative to the estimated baseline rate in 2000 of 64 deaths (model range, 56-73) per 100 000 women: 44% (model range, 35%-60%) of this reduction was associated with screening and 56% (model range, 40%-65%) with treatment. In 2012, the estimated reduction in overall breast cancer mortality rate was 49% (model range, 39%-58%) relative to the estimated baseline rate in 2012 of 63 deaths (model range, 54-73) per 100 000 women: 37% (model range, 26%-51%) of this reduction was associated with screening and 63% (model range, 49%-74%) with treatment. Of the 63% associated with treatment, 31% (model range, 22%-37%) was associated with chemotherapy, 27% (model range, 18%-36%) with hormone therapy, and 4% (model range, 1%-6%) with trastuzumab. The estimated relative contributions associated with screening vs treatment varied by molecular subtype: for ER +/ERBB2− , 36% (model range, 24%-50%) vs 64% (model range, 50%-76%); for ER+ /ERBB2+ , 31% (model range, 23%-41%) vs 69% (model range, 59%-77%); for ER− /ERBB2+ , 40% (model range, 34%-47%) vs 60% (model range, 53%-66%); and for ER− /ERBB2− , 48% (model range, 38%-57%) vs 52% (model range, 44%-62%). Conclusions and Relevance In this simulation modeling study that projected trends in breast cancer mortality rates among US women, decreases in overall breast cancer mortality from 2000 to 2012 were associated with advances in screening and in adjuvant therapy, although the associations varied by breast cancer molecular subtype.

In the Netherlands, routine mammography screening starts at age 50. This starting age may have to be reconsidered because of the increasing breast cancer incidence among women aged 40 to 49 and the recent implementation of digital mammography. We assessed the cost-effectiveness of digital mammography screening that starts between age 40 and 49, using a microsimulation model. Women were screened before age 50, in addition to the current programme (biennial 50-74). Screening strategies varied in starting age (between 40 and 50) and frequency (annual or biennial). The numbers of breast cancers diagnosed, life-years gained (LYG) and breast cancer deaths averted were predicted and incremental cost-effectiveness ratios (ICERs) were calculated to compare screening scenarios. Biennial screening from age 50 to 74 (current strategy) was estimated to gain 157 life years per 1,000 women with lifelong follow-up, compared to a situation without screening, and cost €3,376/LYG (3.5% discounted). Additional screening increased the number of LYG, compared to no screening, ranging from 168 to 242. The costs to generate one additional LYG (i.e., ICER), comparing a screening strategy to the less intensive alternative, were estimated at €5,329 (biennial 48-74 vs. current strategy), €7,628 (biennial 45-74 vs. biennial 48-74), €10,826 (biennial 40-74 vs. biennial 45-74) and €18,759 (annual 40-49-‰+-‰biennial 50-74 vs. biennial 40-74). Other strategies (49-‰+-‰biennial 50-74 and annual 45-49-‰+-‰biennial 50-74) resulted in less favourable ICERs. These findings show that extending the Dutch screening programme by screening between age 40 and 49 is cost-effective, particularly for biennial strategies. What's New? Women in the Netherlands are supposed to start routine mammograms at 50, but that recommendation is under review. Considering advances in technology and increasing cancer rates among younger women, these authors studied the cost-effectiveness of digital mammography starting before age 50. The current protocol, biennial screening from ages 50 to 74, costs €3,376 per life-year-gained (LYG). Extending biennial screening to 48 year olds, the authors found, cost €5,329 per additional LYG, and beginning at age 45 increased the cost to €7,628 per additional LYG. Thus, earlier screening could be a cost-effective strategy.

Introduction The National Breast and Cervical Cancer Early Detection Program (NBCCEDP) provides mammograms and diagnostic services for low-income, uninsured women aged 40-64 years. Mammography facilities within the NBCCEDP gradually shifted from plain-film to digital mammography. The purpose of this study is to assess the impact of replacing film with digital mammography on health effects (deaths averted, life-years gained [LYG]); costs (for screening and diagnostics); and number of women reached. Methods NBCCEDP 2010 data and data representative of the program's target population were used in two established microsimulation models. Models simulated observed screening behavior including different screening intervals (annual, biennial, irregular) and starting ages (40, 50 years) for white, black, and Hispanic women. Model runs were performed in 2012. Results The models predicted 8.0-8.3 LYG per 1,000 film screens for black women, 5.9-7.5 for white women, and 4.0-4.5 for Hispanic women. For all race/ethnicity groups, digital mammography had more LYG than film mammography (2%-4%), but had higher costs (34%-35%). Assuming a fixed budget, 25%-26% fewer women could be served, resulting in 22%-24% fewer LYG if all mammograms were converted to digital. The loss in LYG could be reversed to an 8%-13% increase by only including biennial screening. Conclusions Digital could result in slightly more LYG than film mammography. However, with a fixed budget, fewer women may be served with fewer LYG. Changes in the program, such as only including biennial screening, will increase LYG/screen and could offset the potential decrease in LYG when shifting to digital mammography.

Background: There are no publicly available tools designed specifically to assist policy makers to make informed decisions about the optimal ages of breast cancer screening initiation for different populations of US women. Objective: To use three established simulation models to develop a web-based tool called Mammo OUTPuT. Methods: The simulation models use the 1970 US birth cohort and common parameters for incidence, digital screening performance, and treatment effects. Outcomes include breast cancers diagnosed, breast cancer deaths averted, breast cancer mortality reduction, false-positive mammograms, benign biopsies, and overdiagnosis. The Mammo OUTPuT tool displays these outcomes for combinations of age at screening initiation (every year from 40 to 49), annual versus biennial interval, lifetime versus 10-year horizon, and breast density, compared to waiting to start biennial screening at age 50 and continuing to 74. The tool was piloted by decision makers (n = 16) who completed surveys. Results: The tool demonstrates that benefits in the 40s increase linearly with earlier initiation age, without a specific threshold age. Likewise, the harms of screening increase monotonically with earlier ages of initiation in the 40s. The tool also shows users how the balance of benefits and harms varies with breast density. Surveys revealed that 100% of users (16/16) liked the appearance of the site; 94% (15/16) found the tool helpful; and 94% (15/16) would recommend the tool to a colleague. Conclusions: This tool synthesizes a representative subset of the most current CISNET (Cancer Intervention and Surveillance Modeling Network) simulation model outcomes to provide policy makers with quantitative data on the benefits and harms of screening women in the 40s. Ultimate decisions will depend on program goals, the population served, and informed judgments about the weight of benefits and harms.

Item does not contain fulltext Background: Overdiagnosis is the main harm of cancer screening programs but is difficult to quantify. This review aims to evaluate existing approaches to estimate the magnitude of overdiagnosis in cancer screening in order to gain insight into the strengths and limitations of these approaches and to provide researchers with guidance to obtain reliable estimates of overdiagnosis in cancer screening. Methods: A systematic review was done of primary research studies in PubMed that were published before January 1, 2016, and quantified overdiagnosis in breast cancer screening. The studies meeting inclusion criteria were then categorized by their methods to adjust for lead time and to obtain an unscreened reference population. For each approach, we provide an overview of the data required, assumptions made, limitations, and strengths. Results: A total of 442 studies were identified in the initial search. Forty studies met the inclusion criteria for the qualitative review. We grouped the approaches to adjust for lead time in two main categories: the lead time approach and the excess incidence approach. The lead time approach was further subdivided into the mean lead time approach, lead time distribution approach, and natural history modeling. The excess incidence approach was subdivided into the cumulative incidence approach and early vs late-stage cancer approach. The approaches used to obtain an unscreened reference population were grouped into the following categories: control group of a randomized controlled trial, nonattenders, control region, extrapolation of a prescreening trend, uninvited groups, adjustment for the effect of screening, and natural history modeling. Conclusions: Each approach to adjust for lead time and obtain an unscreened reference population has its own strengths and limitations, which should be taken into consideration when estimating overdiagnosis.

BACKGROUND US breast cancer mortality is declining, but thousands of women still die each year. METHODS Two established simulation models examine 6 strategies that include increased screening and/or treatment or elimination of obesity versus continuation of current patterns. The models use common national data on incidence and obesity prevalence, competing causes of death, mammography characteristics, treatment effects, and survival/cure. Parameters are modified based on obesity (defined as BMI ≥ 30 kg/m2). Outcomes are presented for the year 2025 among women aged 25+ and include numbers of cases, deaths, mammograms and false-positives; age-adjusted incidence and mortality; breast cancer mortality reduction and deaths averted; and probability of dying of breast cancer. RESULTS If current patterns continue, the models project that there would be about 50,100-57,400 (range across models) annual breast cancer deaths in 2025. If 90% of women were screened annually from ages 40 to 54 and biennially from ages 55 to 99 (or death), then 5100-6100 fewer deaths would occur versus current patterns, but incidence, mammograms, and false-positives would increase. If all women received the indicated systemic treatment (with no screening change), then 11,400-14,500 more deaths would be averted versus current patterns, but increased toxicity could occur. If 100% received screening plus indicated therapy, there would be 18,100-20,400 fewer deaths. Eliminating obesity yields 3300-5700 fewer breast cancer deaths versus continuation of current obesity levels. CONCLUSIONS Maximal reductions in breast cancer deaths could be achieved through optimizing treatment use, followed by increasing screening use and obesity prevention. Cancer 2013;119:2541–2548. © 2013 American Cancer Society.

Background: To compare the contribution of 'population' and 'high-risk' approaches to prevention, with regard to their impact on population health in the Netherlands between 1970 and 2010. Methods: Preventive interventions that have had an impact on mortality and morbidity rates were identified using published evaluation studies and routinely collected mortality and morbidity data. These interventions were then classified into population versus high-risk approaches, depending on whether they were targeted to groups identified on the basis of their risk of disease. Results: In the period 1970-2010, 22 new preventive interventions were introduced, which altogether avoided about 16 000 deaths and several hundred thousand disease cases per year in the Netherlands. Tobacco control and road safety measures had the largest impact. Preventive interventions based on a high-risk approach, such as hypertension detection and control and cancer screening, accounted for approximately one quarter of the total health gain. Conclusions: In the period 1970-2010, considerably larger health gains have been achieved with the population approach than with the high-risk approach to prevention. National prevention policies should make judicious use of these complementary approaches to maximize health gain.

Objective Fluctuations in the incidence of breast cancer in Norway in the last three decades are partly explained by the use of hormone replacement therapy and mammography screening, but overdiagnosis has also been suggested as a cause. We assessed the trends in breast cancer incidence and overdiagnosis in Norway. Methods We calibrated our microsimulation model to Norwegian Cancer Registration data. The model takes into account the use of mammography (both within and outside the Norwegian Breast Cancer Screening Programme) and of hormone replacement therapy. We obtained a proper fit of breast cancer incidence in recent years, when assuming an increase in the background risk for breast cancer, and estimated overdiagnosis. Results We estimated a 2% overdiagnosis rate as a fraction of all cancers diagnosed in women aged 50–100, and a 3% overdiagnosis rate as a fraction of all cancers diagnosed in women aged 50–70 (i.e. screening age). If all of the increased incidence would be the result of the detection of slow growing tumours, these estimates were 7% and 11%, respectively. Conclusion Besides mammography and hormone replacement therapy use, additional risk factors contributed to the sudden increase in breast cancer incidence in Norway. Overdiagnosis estimates due to screening were within the range of international plausible estimates.

© 2016 American College of Physicians.Background: Biennial screening is generally recommended for average-risk women aged 50 to 74 years, but tailored screening may provide greater benefits. Objective: To estimate outcomes for various screening intervals after age 50 years based on breast density and risk for breast cancer. Design: Collaborative simulation modeling using national incidence, breast density, and screening performance data. Setting: United States. Patients: Women aged 50 years or older with various combinations of breast density and relative risk (RR) of 1.0, 1.3, 2.0, or 4.0. Intervention: Annual, biennial, or triennial digital mammography screening from ages 50 to 74 years (vs. no screening) and ages 65 to 74 years (vs. biennial digital mammography from ages 50 to 64 years). Measurements: Lifetime breast cancer deaths, life expectancy and quality-adjusted life-years (QALYs), false-positive mammograms, benign biopsy results, overdiagnosis, cost-effectiveness, and ratio of false-positive results to breast cancer deaths averted. Results: Screening benefits and overdiagnosis increase with breast density and RR. False-positive mammograms and benign results on biopsy decrease with increasing risk. Among women with fatty breasts or scattered fibroglandular density and an RR of 1.0 or 1.3, breast cancer deaths averted were similar for triennial versus biennial screening for both age groups (50 to 74 years, median of 3.4 to 5.1 vs. 4.1 to 6.5 deaths averted; 65 to 74 years, median of 1.5 to 2.1 vs. 1.8 to 2.6 deaths averted). Breast cancer deaths averted increased with annual versus biennial screening for women aged 50 to 74 years at all levels of breast density and an RR of 4.0, and those aged 65 to 74 years with heterogeneously or extremely dense breasts and an RR of 4.0. However, harms were almost 2-fold higher. Triennial screening for the average-risk subgroup and annual screening for the highest-risk subgroup cost less than $100 000 per QALY gained. Limitation: Models did not consider women younger than 50 years, those with an RR less than 1, or other imaging methods. Conclusion: Average-risk women with low breast density undergoing triennial screening and higher-risk women with high breast density receiving annual screening will maintain a similar or better balance of benefits and harms than average-risk women receiving biennial screening.

BackgroundControversy persists about optimal mammography screening strategies.ObjectiveTo evaluate screening outcomes, taking into account advances in mammography and treatment of breast cancer.DesignCollaboration of 6 simulation models using national data on incidence, digital mammography performance, treatment effects, and other-cause mortality.SettingUnited States.PatientsAverage-risk U.S. female population and subgroups with varying risk, breast density, or comorbidity.InterventionEight strategies differing by age at which screening starts (40, 45, or 50 years) and screening interval (annual, biennial, and hybrid [annual for women in their 40s and biennial thereafter]). All strategies assumed 100% adherence and stopped at age 74 years.MeasurementsBenefits (breast cancer-specific mortality reduction, breast cancer deaths averted, life-years, and quality-adjusted life-years); number of mammograms used; harms (false-positive results, benign biopsies, and overdiagnosis); and ratios of harms (or use) and benefits (efficiency) per 1000 screens.ResultsBiennial strategies were consistently the most efficient for average-risk women. Biennial screening from age 50 to 74 years avoided a median of 7 breast cancer deaths versus no screening; annual screening from age 40 to 74 years avoided an additional 3 deaths, but yielded 1988 more false-positive results and 11 more overdiagnoses per 1000 women screened. Annual screening from age 50 to 74 years was inefficient (similar benefits, but more harms than other strategies). For groups with a 2- to 4-fold increased risk, annual screening from age 40 years had similar harms and benefits as screening average-risk women biennially from 50 to 74 years. For groups with moderate or severe comorbidity, screening could stop at age 66 to 68 years.LimitationOther imaging technologies, polygenic risk, and nonadherence were not considered.ConclusionBiennial screening for breast cancer is efficient for average-risk populations. Decisions about starting ages and intervals will depend on population characteristics and the decision makers' weight given to the harms and benefits of screening.Primary funding sourceNational Institutes of Health.

Microsimulation modeling was introduced to the social sciences in the 1950s, but did not play any significant role in health care until the 1980s. The rapid growth and plunging cost of computing power in that era supported a sustained penetration of simulation modeling into health services research and policy analysis. In this chapter we provide an overview of how modeling of breast cancer screening is done and review how microsimulations have been used to interpret and understand the results of clinical trials and observational studies, to project results of modifying screening programs and to estimate cost-effectiveness. The limitations of modeling as a method of gaining reliable information are reviewed; the most important potential sources of uncertainty, and how they are dealt with, are discussed. New applications of microsimulation in the field of breast cancer control are mentioned as possible future directions.

Obesity affects multiple points along the breast cancer control continuum from prevention to screening and treatment, often in opposing directions. Obesity is also more prevalent in Blacks than Whites at most ages so it might contribute to observed racial disparities in mortality. We use two established simulation models from the Cancer Intervention and Surveillance Modeling Network (CISNET) to evaluate the impact of obesity on race-specific breast cancer outcomes. The models use common national data to inform parameters for the multiple US birth cohorts of Black and White women, including age- and race-specific incidence, competing mortality, mammography characteristics, and treatment effectiveness. Parameters are modified by obesity (BMI of a parts per thousand yen30 kg/m(2)) in conjunction with its age-, race-, cohort- and time-period-specific prevalence. We measure age-standardized breast cancer incidence and mortality and cases and deaths attributable to obesity. Obesity is more prevalent among Blacks than Whites until age 74; after age 74 it is more prevalent in Whites. The models estimate that the fraction of the US breast cancer cases attributable to obesity is 3.9-4.5 % (range across models) for Whites and 2.5-3.6 % for Blacks. Given the protective effects of obesity on risk among women < 50 years, elimination of obesity in this age group could increase cases for both the races, but decrease cases for women a parts per thousand yen50 years. Overall, obesity accounts for 4.4-9.2 % and 3.1-8.4 % of the total number of breast cancer deaths in Whites and Blacks, respectively, across models. However, variations in obesity prevalence have no net effect on race disparities in breast cancer mortality because of the opposing effects of age on risk and patterns of age- and race-specific prevalence. Despite its modest impact on breast cancer control and race disparities, obesity remains one of the few known modifiable risks for cancer and other diseases, underlining its relevance as a public health target.

Aim The objective of this study was to assess the reliability of a mobility questionnaire (MobQues) that was developed to measure the mobility limitations of children with cerebral palsy (CP) as rated by their parents. A clinical version of the questionnaire, consisting of 47 items (MobQues47), is available, as well as a research version with 28 items for a specific population (MobQues28). Total scores are expressed on a scale of 0 to 100. Method We assessed the interrater reliability between both parents of 289 children with CP (168 males, 121 females, age range 2–13y, Gross Motor Function Classification System levels I–IV) and the intrarater reliability within a subgroup of 38 parents (of 23 children) who completed the MobQues twice. Results For the interrater reliability, high intraclass correlation coefficients (ICCs) were found for the MobQues47 (ICC 0.92) and MobQues28 (ICC 0.87). The standard error of measurement (SEM) was 7.8 and 8.9 respectively. As expected, the intrarater reliability was higher, as represented by higher ICCs (0.96–0.99) and lower SEMs (3.5–4.9) for both MobQues versions. Interpretation The results of this study indicate that the MobQues is a reliable instrument to measure the mobility limitations of children with CP.

BackgroundMany states have laws requiring mammography facilities to tell women with dense breasts and negative results on screening mammography to discuss supplemental screening tests with their providers. The most readily available supplemental screening method is ultrasonography, but little is known about its effectiveness.ObjectiveTo evaluate the benefits, harms, and cost-effectiveness of supplemental ultrasonography screening for women with dense breasts.DesignComparative modeling with 3 validated simulation models.Data sourcesSurveillance, Epidemiology, and End Results Program; Breast Cancer Surveillance Consortium; and medical literature.Target populationContemporary cohort of women eligible for routine screening.Time horizonLifetime.PerspectivePayer.InterventionSupplemental ultrasonography screening for women with dense breasts after a negative screening mammography result.Outcome measuresBreast cancer deaths averted, quality-adjusted life-years (QALYs) gained, biopsies recommended after a false-positive ultrasonography result, and costs.Results of base-case analysisSupplemental ultrasonography screening after a negative mammography result for women aged 50 to 74 years with heterogeneously or extremely dense breasts averted 0.36 additional breast cancer deaths (range across models, 0.14 to 0.75), gained 1.7 QALYs (range, 0.9 to 4.7), and resulted in 354 biopsy recommendations after a false-positive ultrasonography result (range, 345 to 421) per 1000 women with dense breasts compared with biennial screening by mammography alone. The cost-effectiveness ratio was $325,000 per QALY gained (range, $112,000 to $766,000). Supplemental ultrasonography screening for only women with extremely dense breasts cost $246,000 per QALY gained (range, $74,000 to $535,000).Results of sensitivity analysisThe conclusions were not sensitive to ultrasonography performance characteristics, screening frequency, or starting age.LimitationProvider costs for coordinating supplemental ultrasonography were not considered.ConclusionSupplemental ultrasonography screening for women with dense breasts would substantially increase costs while producing relatively small benefits.Primary funding sourceNational Cancer Institute.

In the Netherlands, routine mammography screening starts at age 50. This starting age may have to be reconsidered because of the increasing breast cancer incidence among women aged 40 to 49 and the recent implementation of digital mammography. We assessed the cost-effectiveness of digital mammography screening that starts between age 40 and 49, using a microsimulation model. Women were screened before age 50, in addition to the current programme (biennial 50-74). Screening strategies varied in starting age (between 40 and 50) and frequency (annual or biennial). The numbers of breast cancers diagnosed, life-years gained (LYG) and breast cancer deaths averted were predicted and incremental cost-effectiveness ratios (ICERs) were calculated to compare screening scenarios. Biennial screening from age 50 to 74 (current strategy) was estimated to gain 157 life years per 1,000 women with lifelong follow-up, compared to a situation without screening, and cost €3,376/LYG (3.5% discounted). Additional screening increased the number of LYG, compared to no screening, ranging from 168 to 242. The costs to generate one additional LYG (i.e., ICER), comparing a screening strategy to the less intensive alternative, were estimated at €5,329 (biennial 48-74 vs. current strategy), €7,628 (biennial 45-74 vs. biennial 48-74), €10,826 (biennial 40-74 vs. biennial 45-74) and €18,759 (annual 40-49 + biennial 50-74 vs. biennial 40-74). Other strategies (49 + biennial 50-74 and annual 45-49 + biennial 50-74) resulted in less favourable ICERs. These findings show that extending the Dutch screening programme by screening between age 40 and 49 is cost-effective, particularly for biennial strategies.

Background: Harms and benefits of cancer screening depend on age and comorbid conditions, but reliable estimates are lacking. Objective: To estimate the harms and benefits of cancer screening by age and comorbid conditions to inform decisions about screening cessation. Design: Collaborative modeling with 7 cancer simulation models and common data on average and comorbid condition level-specific life expectancy. Setting: U. S. population. Patients: U. S. cohorts aged 66 to 90 years in 2010 with average health or 1 of 4 comorbid condition levels: none, mild, moderate, or severe. Intervention: Mammography, prostate-specific antigen testing, or fecal immunochemical testing. Measurements: Lifetime cancer deaths prevented and life-years gained (benefits); false-positive test results and overdiagnosed cancer cases (harms). For each comorbid condition level, the age at which harms and benefits of screening were similar to that for persons with average health having screening at age 74 years. Results: Screening 1000 women with average life expectancy at age 74 years for breast cancer resulted in 79 to 96 (range across models) false-positive results, 0.5 to 0.8 overdiagnosed cancer cases, and 0.7 to 0.9 prevented cancer deaths. Although absolute numbers of harms and benefits differed across cancer sites, the ages at which to cease screening were consistent across models and cancer sites. For persons with no, mild, moderate, and severe comorbid conditions, screening until ages 76, 74, 72, and 66 years, respectively, resulted in harms and benefits similar to average-health persons. Limitation: Comorbid conditions influenced only life expectancy. Conclusion: Comorbid conditions are an important determinant of harms and benefits of screening. Estimates of screening benefits and harms by comorbid condition can inform discussions between providers and patients about personalizing screening cessation decisions.