The value of models in informing resource allocation in colorectal cancer screening: the case of The Netherlands

Modelling the impact of bias in fecal immunochemical testing on long-term outcomes of colorectal cancer screening

BACKGROUND

As the impact of unmanaged bias (i.e. systematic source of inaccuracy) in fecal immunochemical test (FIT) analytical performance on long-term colorectal cancer (CRC) outcomes is unknown, we assessed the impact bias in FIT performance in an ongoing FIT-based CRC screening program.

METHODS

This study consisted of two parts: cross-sectional observational data analysis to estimate change in short-term outcomes and microsimulation modelling to estimate change in long-term outcomes assuming different levels of bias by assuming 15 % lower up to 15 % higher Hemoglobin detected in the stool compared to observed. Two scenarios were considered: bias occurring 1) one-time only, due to the occasional bias associated with the FIT kits used in 2020 and 2) consistently due to a constant bias associated with the FIT kits used from 2020 onwards.

RESULTS

With a hypothetical bias of -15 % to +15 %, we observed a positivity rate ranging from 6.7 % to 7.8 %, and a detection rate for CRC between 0.65 % and 0.68 %. Single biases in FIT performance resulted in less than 0.1 % change in long-term CRC screening outcomes, while consistent biases resulted in a much larger change (up to 1.4 % in CRC cases and CRC-related deaths and up to 2.07 % in total costs). Detecting lower Hemoglobin concentrations resulted in a relatively larger change on long-term CRC outcomes in comparison to positive bias.

CONCLUSIONS

Because of the substantial impact of consistent FIT bias, it is important to set evidence-based acceptance criteria of bias on long-term CRC screening outcomes and in particular, the introduction of an asymmetrical or upward shifted tolerance interval for FIT bias.

Population-level impact of the BMJ Rapid Recommendation for colorectal cancer screening: a microsimulation analysis

OBJECTIVE

In 2019, a BMJ Rapid Recommendation advised against colorectal cancer (CRC) screening for adults with a predicted 15-year CRC risk below 3%. Using Switzerland as a case study, we estimated the population-level impact of this recommendation.

DESIGN

We predicted the CRC risk of all respondents to the population-based Swiss Health Survey. We derived the distribution of risk-based screening start age, assuming predicted risk was calculated every 5 years between ages 25 and 70 and screening started when this risk exceeded 3%. Next, the MISCAN-Colon microsimulation model evaluated biennial faecal immunochemical test (FIT) screening with this risk-based start age. As a comparison, we simulated screening initiation based on age and sex.

RESULTS

Starting screening only when predicted risk exceeded 3% meant 82% of women and 90% of men would not start screening before age 65 and 60, respectively. This would require 43%-57% fewer tests, result in 8%-16% fewer CRC deaths prevented and yield 19%-33% fewer lifeyears gained compared with screening from age 50. Screening women from age 65 and men from age 60 had a similar impact as screening only when predicted risk exceeded 3%.

CONCLUSION

With the recommended risk prediction tool, the population impact of the BMJ Rapid Recommendation would be similar to screening initiation based on age and sex only. It would delay screening initiation by 10-15 years. Although halving the screening burdens, screening benefits would be reduced substantially compared with screening initiation at age 50. This suggests that the 3% risk threshold to start CRC screening might be too high.

Evaluation of the "Burgenland PREvention trial of colorectal cancer Disease with ImmunologiCal Testing" (B-PREDICT)-a population-based colorectal cancer screening program

BACKGROUND

The colorectal cancer (CRC) screening program B-PREDICT is a population based invited two stage screening project using a faecal immunochemical test (FIT) for initial screening followed by a colonoscopy for those with a positive FIT. B-PREDICT was compared with the opportunistic screening colonoscopy (OPP-COL), performed in course of the nationwide screening program.

METHODS

Within B-PREDICT all residents of the Austrian federal state Burgenland, aged between 40 and 80 are annually invited to FIT testing. All individuals who underwent initial colonoscopy in Burgenland between 01/2003 and 12/2014, were included in this study. Individuals from the FIT-triggered invited screening program B-PREDICT were compared with those from the non-FIT triggered OPP-COL.

RESULTS

15 133 individuals from B-PREDICT were compared to 10 045 individuals with OPP-COL. CRC detection rates were 1.34% (CI-95%, [1.15; 1.52]) in B-PREDICT compared to 0.54% in OPP-COL (95%-CI, [0.39; 0.68] p < 0.001). The decrease in the age standardized incidence rates of CRC was more pronounced in the population screened with FIT than in the general population screened with colonoscopy. Changes in incidence rates per year were -4.4% (95%-CI, [-5.1; -3.7]) vs. -1.8% (95%-CI, [-1.9; -1.6] p < 0.001).

CONCLUSIONS

B-PREDICT shows a two-fold higher detection rate of CRC as well as HRA compared to OPP-COL.

Modelling the cost-effectiveness of a newborn hearing screening programme; usability and pitfalls

OBJECTIVE

The EUSCREEN project concerns the study of European vision and hearing screening programmes. Part of the project was the development of a cost-effectiveness model to analyse such programmes. We describe the development and usability of an online tool to enable stakeholders to design, analyse or modify a newborn hearing screening (NHS) programme.

DESIGN

Data from literature, from existing NHS programmes, and observations by users were used to develop and refine the tool. Required inputs include prevalence of the hearing impairment, test sequence and its timing, attendance, sensitivity, and specificity of each screening step. Outputs include the number of cases detected and the costs of screening and diagnostics.

STUDY SAMPLE

Eleven NHS programmes with reliable data.

RESULTS

Three analyses are presented, exploring the effect of low attendance, number of screening steps, testing in the maternity ward, or screening at a later age, on the benefits and costs of the programme. Knowledge of the epidemiology of a staged screening programme is crucial when using the tool.

CONCLUSIONS

This study presents a tool intended to aid stakeholders to design a new or analyse an existing hearing screening programme in terms of benefits and costs.

Potential global loss of life expected due to COVID-19 disruptions to organised colorectal cancer screening

Background

Screening for colorectal cancer (CRC) decreases cancer burden through removal of precancerous lesions and early detection of cancer. The COVID-19 pandemic has disrupted organised CRC screening programs worldwide, with some programs completely suspending screening and others experiencing significant decreases in participation and diagnostic follow-up. This study estimated the global impact of screening disruptions on CRC outcomes, and potential effects of catch-up screening.

Methods

Organised screening programs were identified in 29 countries, and data on participation rates and COVID-related changes to screening in 2020 were extracted where available. Four independent microsimulation models (ASCCA, MISCAN-Colon, OncoSim, and Policy1-Bowel) were used to estimate the long-term impact on CRC cases and deaths, based on decreases to screening participation in 2020. For countries where 2020 participation data were not available, changes to screening were approximated based on excess mortality rates. Catch-up strategies involving additional screening in 2021 were also simulated.

Findings

In countries for which direct data were available, organised CRC screening volumes at a country level decreased by an estimated 1.3-40.5% in 2020. Globally, it is estimated that COVID-related screening decreases led to a deficit of 7.4 million fewer faecal screens performed in 2020. In the absence of any organised catch-up screening, this would lead to an estimated 13,000 additional CRC cases and 7,900 deaths globally from 2020 to 2050; 79% of the additional cases and 85% of additional deaths could have been prevented with catch-up screening, respectively.

Interpretation

COVID-19-related disruptions to screening will cause excess CRC cases and deaths, but appropriately implemented catch-up screening could have reduced the burden by over 80%. Careful management of any disruption is key to improving the resilience of colorectal cancer screening programs.

Funding

The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This work was supported by Cancer Council New South Wales, Health Canada, and Dutch National Institute for Public Health and Environment.

Personalized colorectal cancer screening: study protocol of a mixed-methods study on the effectiveness of tailored intervals based on prior f-Hb concentration in a fit-based colorectal cancer screening program (PERFECT-FIT)

BACKGROUND

In 2014, the national population-based colorectal cancer (CRC) screening program was implemented in the Netherlands. Biennial fecal immunochemical testing (FIT) for hemoglobin (Hb) is used at a cut-off of 47 µg Hb per gram feces. The CRC screening program successfully started, with high participation rates and yield of screening. Now that the program has reached a steady state, there is potential to further optimize the program. Previous studies showed that prior fecal Hb (f-Hb) concentrations just below the FIT cut-off are associated with a higher risk for detection of advanced neoplasia (AN) at subsequent screening rounds. We aim to achieve a better balance between the harms and benefits of CRC screening by offering participants tailored invitation intervals based on prior f-Hb concentrations after negative FIT.

METHODS

This mixed-methods study will be performed within the Dutch national CRC screening program and will consist of: (1) a randomized controlled trial (RCT), (2) focus group studies, and (3) decision modelling. The primary outcome is the yield of AN per screened individual in personalized screening vs. uniform screening. Secondary outcomes are perspectives on, acceptability of and adherence to personalized screening, as well as long-term outcomes of personalized vs. uniform screening. The RCT will include 20,000 participants of the Dutch CRC screening program; 10,000 in the intervention and 10,000 in the control arm. The intervention arm will receive a personalized screening interval based on the prior f-Hb concentration (1, 2 or 3 years). The control arm will receive a screening interval according to current practice (2 years). The focus group studies are designed to understand individuals' perspectives on and acceptability of personalized CRC screening. Results of the RCT will be incorporated into the MISCAN-Colon model to determine long-term benefits, harms, and costs of personalized vs. uniform CRC screening.

DISCUSSION

The aim of this study is to evaluate the yield, feasibility, acceptability and (cost-) effectiveness of personalized CRC screening through tailored invitation intervals based on prior f-Hb concentrations. This knowledge may be of guidance for health policy makers and may provide evidence for implementing personalized CRC screening in The Netherlands and/or other countries using FIT as screening modality.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT05423886, June 21, 2022, https://clinicaltrials.gov/ct2/show/NCT05423886.

Impact of surgical versus endoscopic management of complex nonmalignant polyps in a colorectal cancer screening program

BACKGROUND

When complex nonmalignant polyps are detected in colorectal cancer (CRC) screening programs, patients may be referred directly to surgery or may first undergo additional endoscopy for attempted endoscopic removal by an expert. We compared the impact of both strategies on screening effectiveness and costs.

METHODS

We used MISCAN-Colon to simulate the Dutch screening program, and projected CRC deaths prevented, quality-adjusted life-years (QALYs) gained, and costs for two scenarios: 1) surgery for all complex nonmalignant polyps; 2) attempted removal by an expert endoscopist first. We made the following assumptions: 3.9 % of screen-detected large nonmalignant polyps were complex; associated surgery mortality was 0.7 %; the rate of successful removal by an expert was 87 %, with 0.11 % mortality.

RESULTS

The screening program was estimated to prevent 11.2 CRC cases (-16.7 %) and 10.1 CRC deaths (-27.1 %), resulting in 32.9 QALYs gained (+ 17.2 %) per 1000 simulated individuals over their lifetimes compared with no screening. The program would also result in 2.1 surgeries for complex nonmalignant polyps with 0.015 associated deaths per 1000 individuals. If, instead, these patients were referred to an expert endoscopist first, only 0.2 patients required surgery, reducing associated deaths by 0.013 at the expense of 0.003 extra colonoscopy deaths. Compared with direct referral to surgery, referral to an expert endoscopist gained 0.2 QALYs and saved €12 500 per 1000 individuals in the target population.

CONCLUSION

Referring patients with complex polyps to an expert endoscopist first reduced some surgery-related deaths while substantially improving cost-effectiveness of the screening program.

Cost-effectiveness of colorectal cancer screening in Slovakia

BACKGROUND

Colorectal cancer (CRC) is an ideal disease for screening due to known and detectable precursor lesions and slow progression from benign adenoma to invasive cancer. The introduction of organized population-based screening programs reduces the burden of colorectal cancer and increases the quality of the screening process with a more favorable harm to benefit ratio compared to opportunistic screening.

METHODS

The study used the microsimulation screening analysis-colon simulation model for the estimation of the effect of various factors on cancer incidence and mortality. The model simulated the Slovakian population from 2018 to 2050. Study includes the analysis of two screening strategies the fecal immunochemical test (FIT) every 2 years and annual FIT. Cost-effectiveness parameters were evaluated comparing each simulated screening scenario with no screening.

RESULTS

Compared to no screening, the biennial FIT would detect 29 600 CRC cases and annual FIT 37 800 CRC cases. Mortality due to CRC showed benefits for both strategies with 17,38% reduction in biennial FIT and 24,67% reduction in annual FIT approach. Both screening programs were more costly as well as more effective compared to no screening. The ICER for biennial FIT strategy was 1776 EUR per 1 QALY and for the annual FIT 3991 EUR per 1 QALY.

CONCLUSIONS

In summary, this is the first cost-effectiveness analysis focusing on multiple national CRC screening strategies in Slovakia. Both strategies demonstrated cost-effectiveness compared to no screening. However, for optimal population-based programmatic screening strategy, the policymakers should also consider human resources availability, acceptability of screening test among the population or additional resources including the screening funding.

Cost-effectiveness analysis of colorectal cancer screening in Shanghai, China: a modelling study

•

The current Shanghai CRC screening program is cost-effective.

•

Changing to a validated FIT would make the program more efficient.

•

The results were sensitive to an increase in the cost of the validated FIT.

•

The results were sensitive to more participation in screening and colonoscopy.

Background

The current community-based colorectal cancer (CRC) screening program in Shanghai, launched in 2013, invited individuals aged 50–74 years to triennial screening with a qualitative faecal immunochemical test (FIT) and questionnaire-based risk assessment (RA). We aimed to evaluate the effectiveness and cost-effectiveness of the existing Shanghai screening program and compare it to using a validated two-sample quantitative FIT.

Methods

We simulated four strategies (no screening, Shanghai FIT, Shanghai FIT + RA and validated FIT) for the Shanghai screening program and evaluated CRC incidence, CRC mortality, the number of life years gained (LYG), the number of FITs, and colonoscopies required for each. An incremental cost-effectiveness analysis was performed to assess the cost- effectiveness of each strategy.

Results

All screening modalities reduced CRC incidence and CRC mortality, gained extra number of LYG compared to no screening. Screening using the Shanghai FIT and validated FIT reduced CRC incidence from 45 cases to 43 per 1,000 simulated individuals (4.4%). Incidence was reduced to 42 cases (6.7%) using the Shanghai FIT + RA. All screening strategies reduced CRC mortality by 10.0% (from 10 to 9 deaths) and resulted in 6 to 7 LYG. The validated FIT was the most cost-effective among the evaluated strategies (ICER ¥26,461 per LYG).

Conclusions

Our findings show that the current Shanghai screening program is (cost-) effective compared to no screening, but changing to a validated FIT would make the program more efficient.

Modelling optimal use of temporarily restricted colonoscopy capacity in a FIT-based CRC screening program: Application during the COVID-19 pandemic

Objective

The COVID-19 pandemic forced colorectal cancer (CRC) screening programs to downscale their colonoscopy capacity. In this study, we assessed strategies to deal with temporary restricted colonoscopy capacity in a FIT-based CRC screening program while aiming to retain the maximum possible preventive effect of the screening program.

Design

We simulated the Dutch national CRC screening program inviting individuals between ages 55 and 75 for biennial FIT using the MISCAN-Colon model including the 3-month disruption in the first half of 2020 due to the COVID-19 pandemic. For the second half of 2020 and 2021, we simulated three different strategies for the total target population: 1) increasing the FIT cut-off, 2) skipping one screening for specific screening ages, and 3) extending the screening interval. We estimated the impact on required colonoscopy capacity in 2020–2021 and life years (LYs) lost in the long-term.

Results

Increasing the FIT cut-off, skipping screening ages and extending the screening interval resulted in a maximum reduction of 25,100 (-17.0%), 16,100(-10.9%) and 19,000 (-12.9%) colonoscopies, respectively. Modelling an increased FIT cut-off, the number of LYs lost ranged between 1,400 and 4,400. Skipping just a single screening age resulted in approximately 2,700 LYs lost and this was doubled in case of skipping two screening ages. Extending the screening interval up to 34 months had the smallest impact on LYs lost (up to 1,100 LYs lost).

Conclusion

This modelling study shows that to anticipate on restricted colonoscopy capacity, temporarily extending the screening interval retains the maximum possible preventive effect of the CRC screening program.

Optimising colorectal cancer screening in Shanghai, China: a modelling study

INTRODUCTION

To reduce the burden of colorectal cancer (CRC) in Shanghai, China, a CRC screening programme was commenced in 2013 inviting those aged 50-74 years to triennial screening with a faecal immunochemical test (FIT) and risk assessment. However, it is unknown whether this is the optimal screening strategy for this population. We aimed to determine the optimal CRC screening programme for Shanghai in terms of benefits, burden, harms and cost-effectiveness.

METHODS

Using Microsimulation Screening Analysis-Colon (MISCAN-Colon), we estimated the costs and effects of the current screening programme compared with a situation without screening. Subsequently, we estimated the benefits (life years gained (LYG)), burden (number of screening events, colonoscopies and false-positive tests), harms (number of colonoscopy complications) and costs (Renminb (¥)) of screening for 324 alternative screening strategies. We compared several different age ranges, screening modalities, intervals and FIT cut-off levels. An incremental cost-effectiveness analysis determined the optimal strategy assuming a willingness-to-pay of ¥193 931 per LYG.

RESULTS

Compared with no screening, the current screening programme reduced CRC incidence by 40% (19 cases per 1000 screened individuals) and CRC mortality by 67% (7 deaths). This strategy gained 32 additional life years, increased colonoscopy demand to 1434 per 1000 individuals and cost an additional ¥199 652. The optimal screening strategy was annual testing using a validated one-sample FIT, with a cut-off of 10 µg haemoglobin per gram from ages 45 to 80 years (incremental cost-effectiveness ratio, ¥62 107). This strategy increased LY by 0.18% and costs by 27%. Several alternative cost-effective strategies using a validated FIT offered comparable benefits to the current programme but lower burden and costs.

CONCLUSIONS

Although the current screening programme in Shanghai is effective at reducing CRC incidence and mortality, the programme could be optimised using a validated FIT. When implementing CRC screening, jurisdictions with limited health resources should use a validated test.

Microsimulation Model for Prevention and Intervention of Coloretal Cancer in China (MIMIC-CRC): Development, Calibration, Validation, and Application

Introduction

A microsimulation model provides important references for decision-making regarding colorectal cancer (CRC) prevention strategies, yet such a well-validated model is scarce in China.

Methods

We comprehensively introduce the development of MIcrosimulation Model for the prevention and Intervention of Colorectal Cancer in China (MIMIC-CRC). The MIMIC-CRC was first constructed to simulate the natural history of CRC based on the adenoma-carcinoma pathway. The parameters were calibrated and validated using data from population-based cancer registry data and CRC screening programs. Furthermore, to assess the model’s external validity, we compared the model-derived results to outcome patterns of a sigmoidoscopy screening trial in the UK [UK Flexible Sigmoidoscopy Screening (UKFSS) trial]. Finally, we evaluated the application potential of the MIMIC-CRC model in CRC screening by comparing the 8 different strategies.

Results

We found that most of the model-predicted colorectal lesion prevalence was within the 95% CIs of observed prevalence in a large population-based CRC screening program in China. In addition, model-predicted sex- and age-specific CRC incidence and mortality were equivalent to the registry-based data. The hazard ratios of model-estimated CRC-related incidence and mortality for sigmoidoscopy screening compared to no screening were 0.60 and 0.51, respectively, which were comparable to the reported results of the UKFSS trial. Moreover, we found that all 8 strategies could reduce CRC incidence and mortality compared to no screening.

Conclusions

The well-calibrated and validated MIMIC-CRC model may represent a valid tool to assess the comparative effectiveness of CRC screening strategies and will be useful for further decision-making to CRC prevention.

Optimizing screening with faecal immunochemical test for both sexes - Cost-effectiveness analysis from Finland

A faecal immunochemical test (FIT) screening pilot was introduced in Finland in 2019 with sex-specific screening strategies. This study aims to model cost-effectiveness of sex-specific strategies for the whole population, and to assess whether the current strategies are optimal. We developed separate MISCAN-Colon models, including different FIT performances, for the Finnish men and women using the first-year data of the FIT screening pilot. We evaluated 180 FIT strategies varying in FIT cut-off, screening interval, age to start, and age to stop screening, and compared them to no-screening by sex. We used incremental cost-effectiveness ratios (ICERs) to identify the optimal strategy after combining all male and female strategies and restricting the analysis by costs and referral rate to diagnostic colonoscopies. Offering annual FIT screening with a cut-off of 25 μg/g at 50-79 years in men and with a cut-off of 10 μg/g at 55-69 years in women was optimal. This combined strategy prevented 28% of colorectal cancer (CRC) cases and 55% of CRC deaths with acceptable costs (ICER = 9000€/life-years gained). Screening at the current target age of 60-74 years was suboptimal for both sexes. Among strategies with the same target age and interval for both sexes, expected benefits from optimal screening were lower but still reasonable. Our results support a wider age range of screening in men, and a lower cut-off for a positive test in women when restrictions on colonoscopy capacity and costs are in place. National FIT screening program should start at younger age.

Colorectal Cancer Screening within Colonoscopy Capacity Constraints: Can FIT-Based Programs Save More Lives by Trading off More Sensitive Test Cutoffs against Longer Screening Intervals?

Introduction. Colorectal cancer (CRC) prevention programs using fecal immunochemical testing (FIT) in screening rely on colonoscopy for secondary and surveillance testing. Colonoscopy capacity is an important constraint. Some European programs lack sufficient capacity to provide optimal screening intensity regarding age ranges, intervals, and FIT cutoffs. It is currently unclear how to optimize programs within colonoscopy capacity constraints. Design. Microsimulation modeling, using the MISCAN-Colon model, was used to determine if more effective CRC screening programs can be identified within constrained colonoscopy capacity. A total of 525 strategies were modeled and compared, varying 3 key screening parameters: screening intervals, age ranges, and FIT cutoffs, including previously unevaluated 4- and 5-year screening intervals (using a lifetime horizon and 100% adherence). Results were compared with the policy decisions taken in Ireland to provide CRC screening within available colonoscopy capacity. Outcomes estimated net costs, quality-adjusted life-years (QALYs), and required colonoscopies. The optimal strategies within finite colonoscopy capacity constraints were identified. Results. Combining a reduced FIT cutoff of 10 µg Hb/g, an extended screening interval of 4 y and an age range of 60–72 y requires 6% fewer colonoscopies, reduces net costs by 23% while preventing 15% more CRC deaths and saving 16% more QALYs relative to a strategy (FIT 40 µg Hb/g, 2-yearly, 60–70 year) approximating current policy. Conclusion. Previously overlooked longer screening intervals may optimize cancer prevention with finite colonoscopy capacity constraints. Changes could save lives, reduce costs, and relieve colonoscopy capacity pressures. These findings are relevant to CRC screening programs across Europe that employ FIT-based testing, which face colonoscopy capacity constraints.

Risk-stratified strategies in population screening for colorectal cancer

Colorectal cancer (CRC) screening has been demonstrated to reduce CRC incidence and mortality. However, besides such benefits, CRC screening is also associated with potential harmful effects. In an ideal world, screening would only be directed to the small proportion of the population that might potentially benefit. Risk‐based screening can be seen as a first step towards this ideal world, by redistributing screening resources from low‐risk to high‐risk individuals. In theory, this should result in scarce resources being used in individuals who benefit most, while intensity of screening is reduced in individuals who benefit less, hence improving the benefit‐harm ratio among all invitees. Available strategies that have been proposed for risk‐based CRC screening include using information on age, sex, prior screening history, lifestyle and/or genetic information. Implementation of risk‐based screening requires careful consideration of reliable risk prediction models, participation with screening and informed decision‐making. While it is important to recognise the limitations of current approaches, available evidence suggests that it might be feasible to start planning the introduction of tailored strategies within screening programmes. Implementing risk‐based screening based on age, sex and prior screening history alone would already represent a substantial improvement over current uniform screening approaches. We propose that it is time that screening programmes start there and continue striving towards more comprehensive approaches embedding primary prevention as an effective approach to lower risk for everyone.

Comparative benefit and cost-effectiveness of mailed-out faecal immunochemical tests vs collection at the general practitioner

BACKGROUND

Participation in the colorectal cancer screening programme in France has been well below the 45% considered acceptable by European guidelines, potentially attributable to the need to collect the faecal immunochemical test (FIT) at the general practitioner.

AIM

To estimate the potential benefits and costs of including the FIT in the invitation letter.

METHODS

A well-established microsimulation model was used to simulate the French population 35 years and older in 2018. We estimated quality-adjusted life-years (QALY) gained, costs and cost-effectiveness of the current screening programme, and compared it to a variation of the programme where the FIT was mailed to participants and adherence was assumed to increase to 45%. We also estimated the threshold increase in participation needed to make this intervention cost-effective.

RESULTS

Under the current programme, 53.8 colorectal cancer (CRC) cases and 25.2 CRC deaths per 1000 individuals are expected to occur over a lifetime. If sending out the FIT increases screening participation to 45%, this intervention would result in 6% fewer CRC deaths and 3% fewer CRC cases, resulting in an estimated cost-effectiveness ratio of €2149 per QALY gained. Sending out the FIT would only need to increase participation by 0.7% point for this intervention to be considered cost-effective.

CONCLUSION

Including the FIT in the invitation letter is likely a very cost-effective intervention to increase participation in CRC screening. These results for France are also informative for many other countries around the world where FIT needs to be collected at pharmacies or general practitioners.

Cost-Effectiveness of Multitarget Stool DNA Testing vs Colonoscopy or Fecal Immunochemical Testing for Colorectal Cancer Screening in Alaska Native People

OBJECTIVE

To estimate the cost-effectiveness of multitarget stool DNA testing (MT-sDNA) compared with colonoscopy and fecal immunochemical testing (FIT) for Alaska Native adults.

PATIENTS AND METHODS

A Markov model was used to evaluate the 3 screening test effects over 40 years. Outcomes included colorectal cancer (CRC) incidence and mortality, costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios (ICERs). The study incorporated updated evidence on screening test performance and adherence and was conducted from December 15, 2016, through November 6, 2019.

RESULTS

With perfect adherence, CRC incidence was reduced by 52% (95% CI, 46% to 56%) using colonoscopy, 61% (95% CI, 57% to 64%) using annual FIT, and 66% (95% CI, 63% to 68%) using MT-sDNA. Compared with no screening, perfect adherence screening extends life by 0.15, 0.17, and 0.19 QALYs per person with colonoscopy, FIT, and MT-sDNA, respectively. Colonoscopy is the most expensive strategy: approximately $110 million more than MT-sDNA and $127 million more than FIT. With imperfect adherence (best case), MT-sDNA resulted in 0.12 QALYs per person vs 0.05 and 0.06 QALYs per person by FIT and colonoscopy, respectively. Probabilistic sensitivity analyses supported the base-case analysis. Under varied adherence scenarios, MT-sDNA either dominates or is cost-effective (ICERs, $1740-$75,868 per QALY saved) compared with FIT and colonoscopy.

CONCLUSION

Each strategy reduced costs and increased QALYs compared with no screening. Screening by MT-sDNA results in the largest QALY savings. In Markov model analysis, screening by MT-sDNA in the Alaska Native population was cost-effective compared with screening by colonoscopy and FIT for a wide range of adherence scenarios.

Impact of the COVID-19 pandemic on faecal immunochemical test-based colorectal cancer screening programmes in Australia, Canada, and the Netherlands: a comparative modelling study

BACKGROUND

Colorectal cancer screening programmes worldwide have been disrupted during the COVID-19 pandemic. We aimed to estimate the impact of hypothetical disruptions to organised faecal immunochemical test-based colorectal cancer screening programmes on short-term and long-term colorectal cancer incidence and mortality in three countries using microsimulation modelling.

METHODS

In this modelling study, we used four country-specific colorectal cancer microsimulation models-Policy1-Bowel (Australia), OncoSim (Canada), and ASCCA and MISCAN-Colon (the Netherlands)-to estimate the potential impact of COVID-19-related disruptions to screening on colorectal cancer incidence and mortality in Australia, Canada, and the Netherlands annually for the period 2020-24 and cumulatively for the period 2020-50. Modelled scenarios varied by duration of disruption (3, 6, and 12 months), decreases in screening participation after the period of disruption (0%, 25%, or 50% reduction), and catch-up screening strategies (within 6 months after the disruption period or all screening delayed by 6 months).

FINDINGS

Without catch-up screening, our analysis predicted that colorectal cancer deaths among individuals aged 50 years and older, a 3-month disruption would result in 414-902 additional new colorectal cancer diagnoses (relative increase 0·1-0·2%) and 324-440 additional deaths (relative increase 0·2-0·3%) in the Netherlands, 1672 additional diagnoses (relative increase 0·3%) and 979 additional deaths (relative increase 0·5%) in Australia, and 1671 additional diagnoses (relative increase 0·2%) and 799 additional deaths (relative increase 0·3%) in Canada between 2020 and 2050, compared with undisrupted screening. A 6-month disruption would result in 803-1803 additional diagnoses (relative increase 0·2-0·4%) and 678-881 additional deaths (relative increase 0·4-0·6%) in the Netherlands, 3552 additional diagnoses (relative increase 0·6%) and 1961 additional deaths (relative increase 1·0%) in Australia, and 2844 additional diagnoses (relative increase 0·3%) and 1319 additional deaths (relative increase 0·4%) in Canada between 2020 and 2050, compared with undisrupted screening. A 12-month disruption would result in 1619-3615 additional diagnoses (relative increase 0·4-0·9%) and 1360-1762 additional deaths (relative increase 0·8-1·2%) in the Netherlands, 7140 additional diagnoses (relative increase 1·2%) and 3968 additional deaths (relative increase 2·0%) in Australia, and 5212 additional diagnoses (relative increase 0·6%) and 2366 additional deaths (relative increase 0·8%) in Canada between 2020 and 2050, compared with undisrupted screening. Providing immediate catch-up screening could minimise the impact of the disruption, restricting the relative increase in colorectal cancer incidence and deaths between 2020 and 2050 to less than 0·1% in all countries. A post-disruption decrease in participation could increase colorectal cancer incidence by 0·2-0·9% and deaths by 0·6-1·6% between 2020 and 2050, compared with undisrupted screening.

INTERPRETATION

Although the projected effect of short-term disruption to colorectal cancer screening is modest, such disruption will have a marked impact on colorectal cancer incidence and deaths between 2020 and 2050 attributable to missed screening. Thus, it is crucial that, if disrupted, screening programmes ensure participation rates return to previously observed rates and provide catch-up screening wherever possible, since this could mitigate the impact on colorectal cancer deaths.

FUNDING

Cancer Council New South Wales, Health Canada, and Dutch National Institute for Public Health and Environment.

Implementation of lung cancer screening: what are the main issues?

Two large-scale RCTs have shown computed tomography (CT) lung cancer screening to be efficacious in reducing lung cancer mortality (8–24% in men, 26–59% in women). However, lung cancer screening implicitly means personalised and risk-based approaches. Health care systems’ implementation of personalised screening and prevention is still sparse, and likely to be of variable quality, because of important remaining uncertainties, which have been incompletely addressed or not at all so far. Further optimisation of lung cancer screening programs is expected to reduce harms and maintain or enhance benefit for eligible European citizens, whilst significantly reducing health care costs. Some main uncertainties (e.g., Risk-based eligibility, Risk-based screening intervals, Volume CT screening, Smoking Cessation, Gender and Sex differences, Cost-Effectiveness) are discussed in this review. 4-IN-THE-LUNG-RUN (acronym for: Towards INdividually tailored INvitations, screening INtervals and INtegrated co-morbidity reducing strategies in lung cancer screening) is the first multi-centred implementation trial on volume CT lung cancer screening amongst 24,000 males and females, at high risk for developing lung cancer, across five European countries, started in January 2020. Through providing answers to the remaining questions with this trial, many EU citizens will swiftly benefit from this high-quality screening technology, others will face less harms than previously anticipated, and health care costs will be substantially reduced. Implementing a new cancer screening programme is a major task, with many stakeholders and many possible facilitators but also barriers and obstacle.

Development and Validation of Three Regional Microsimulation Models for Predicting Colorectal Cancer Screening Benefits in Europe

Background. Validated microsimulation models have been shown to be useful tools in providing support for colorectal cancer (CRC) screening decisions. Aiming to assist European countries in reducing CRC mortality, we developed and validated three regional models for evaluating CRC screening in Europe. Methods. Microsimulation Screening Analysis–Colon (MISCAN-Colon) model versions for Italy, Slovenia, and Finland were quantified using data from different national institutions. These models were validated against the best available evidence for the effectiveness of screening from their region (when available): the Screening for COlon REctum (SCORE) trial and the Florentine fecal immunochemical test (FIT) screening study for Italy; the Norwegian Colorectal Cancer Prevention (NORCCAP) trial and the guaiac fecal occult blood test (gFOBT) Finnish population-based study for Finland. When published evidence was not available (Slovenia), the model was validated using cancer registry data. Results. Our three models reproduced age-specific CRC incidence rates and stage distributions in the prescreening period. Moreover, the Italian and Finnish models replicated CRC mortality reductions (reasonably) well against the best available evidence. CRC mortality reductions were predicted slightly larger than those observed (except for the Florentine FIT study), but consistently within the corresponding 95% confidence intervals. Conclusions. Our findings corroborate the MISCAN-Colon reliability in supporting decision making on CRC screening. Furthermore, our study provides the model structure for an additional tool (EU-TOPIA CRC evaluation tool: http://miscan.eu-topia.org) that aims to help policymakers and researchers monitoring or improving CRC screening in Europe.

Modeling costs and benefits of the organized colorectal cancer screening programme and its potential future improvements in Hungary

OBJECTIVE

The national population-based colorectal cancer screening programme in Hungary was initiated in December 2018. We aimed to evaluate the current programme and investigate the costs and benefits of potential future changes to overcome the low coverage of the target population.

METHODS

We performed an economic evaluation from a healthcare payer perspective using an established micro-simulation model (Microsimulation Screening Analysis-Colon). We simulated costs and benefits of screening with fecal immunochemical test in the Hungarian population aged 50-100, investigating also the impact of potential future scenarios which were assumed to increase invitation coverage: improvement of the IT platform currently used by GPs or distributing the tests through pharmacies instead of GPs.

RESULTS

The model predicted that the current screening programme could lead to 6.2% colorectal cancer mortality reduction between 2018 and 2050 compared to no screening. Even higher reductions, up to 16.6%, were estimated when tests were distributed through pharmacies and higher coverage was assumed. This change in the programme was estimated to require up to 26 million performed fecal immunochemical tests and 1 million colonoscopies for the simulated period. These future scenarios have acceptable cost-benefit ratios of €8000-€8700 per life-years gained depending on the assumed adherence of invited individuals.

CONCLUSIONS

With its limitations, the current colorectal cancer screening programme in Hungary will have a modest impact on colorectal cancer mortality. Significant improvements in mortality reduction could be made at acceptable costs, if the tests were to be distributed by pharmacies allowing the entire target population to be invited.

Effect and cost-effectiveness of national gastric cancer screening in Japan: a microsimulation modeling study

BACKGROUND

A national endoscopic screening program for gastric cancer was rolled out in Japan in 2015. We used a microsimulation model to estimate the cost-effectiveness of current screening guidelines and alternative screening strategies in Japan.

METHODS

We developed a microsimulation model that simulated a virtual population corresponding to the Japanese population in risk factor profile and life expectancy. We evaluated 15 endoscopic screening scenarios with various starting ages, stopping ages, and screening intervals. The primary outcomes were quality-adjusted life-years (QALYs), costs, and incremental cost-effectiveness ratio. Cost-effective screening strategies were determined using a willingness-to-pay threshold of $50,000 per QALY gained. One-way sensitivity and probabilistic sensitivity analyses were done to explore model uncertainty.

RESULTS

Using the threshold of $50,000 per QALY, a triennial screening program for individuals aged 50 to 75 years was the cost-effective strategy, with an incremental cost-effectiveness ratio of $45,665. Compared with no endoscopic screening, this strategy is predicted to prevent 63% of gastric cancer mortality and confer 27.2 QALYs gained per 1000 individuals over a lifetime period. Current screening guidelines were not on the cost-effectiveness efficient frontier. The results were robust on one-way sensitivity analyses and probabilistic sensitivity analysis.

CONCLUSIONS

This modeling study suggests that the endoscopic screening program in Japan would be cost-effective when implemented between age 50 and 75 years, with the screening repeated every 3 years. These findings underscore the need for further evaluation of the current gastric cancer screening recommendations.

Risk-Adapted Cutoffs in Colorectal Cancer Screening by Fecal Immunochemical Tests

INTRODUCTION

Fecal immunochemical tests (FITs) for hemoglobin are increasingly used in colorectal cancer (CRC) screening. The use of uniform positivity thresholds (cutoffs) within screening populations is expected to imply lower positive predictive values (PPVs) and higher numbers of colonoscopies needed (numbers needed to scope [NNSs]) to detect advanced neoplasms among screening participants at lower risk compared with those at higher risk. We aimed to assess such variation and its potential implications in a large screening cohort.

METHODS

A quantitative FIT (FOB Gold; Sentinel Diagnostics, Milan, Italy) was conducted in fecal samples collected by 4,332 participants of screening colonoscopy before bowel preparation. Participants were classified into 3 risk groups (low, medium, and high) by tertiles of a previously derived risk-factor-based risk score. We determined the variation of PPVs and NNSs for detecting advanced neoplasms (i.e., CRC or advanced adenoma) when using the same FIT cutoffs and variation of FIT cutoffs that would yield uniform PPVs across risk groups.

RESULTS

When a fixed FIT cutoff of 10 μg/g was used, the PPV increased from 23.3% to 41.8% from the low- to the high-risk group, with NNS decreasing from 4.3 to 2.4 (P < 0.001). Similar variations of PPVs and NNSs across risk groups were observed at higher FIT cutoffs. When risk group-specific cutoffs were defined to achieve fixed PPVs of 25%, 30%, and 35% across all risk groups, cutoffs varied from 5.3 to 11.4, 6.5 to 18.7, and 7.5 to 31.0 μg hemoglobin/g feces, respectively, between high- and low-risk groups (P < 0.05 for all differences).

DISCUSSION

Using risk-adapted cutoffs may help to achieve target levels of PPV and NNS and might be an option to consider for personalized FIT-based CRC screening.

Simulation modeling validity and utility in colorectal cancer screening delivery: A systematic review

OBJECTIVE

This study sought to assess the impact and validity of simulation modeling in informing decision making in a complex area of healthcare delivery: colorectal cancer (CRC) screening.

MATERIALS AND METHODS

We searched 10 electronic databases for English-language articles published between January 1, 2008, and March 1, 2019, that described the development of a simulation model with a focus on average-risk CRC screening delivery. Included articles were reviewed for evidence that the model was validated, and provided real or potential contribution to informed decision making using the GRADE EtD (Grading of Recommendations Assessment, Development, and Evaluation Evidence to Decision) framework.

RESULTS

A total of 43 studies met criteria. The majority used Markov modeling (n = 31 [72%]) and sought to determine cost-effectiveness, compare screening modalities, or assess effectiveness of screening. No study reported full model validation and only (58%) reported conducting any validation. Majority of models were developed to address a specific health systems or policy question; few articles report the model's impact on this decision (n = 39 [91%] vs. n = 5 [12%]). Overall, models provided evidence relevant to every element important to decision makers as outlined in the GRADE EtD framework.

DISCUSSION AND CONCLUSION

Simulation modeling contributes evidence that is considered valuable to decision making in CRC screening delivery, particularly in assessing cost-effectiveness and comparing screening modalities. However, the actual impact on decisions and validity of models is lacking in the literature. Greater validity testing, impact assessment, and standardized reporting of both is needed to understand and demonstrate the reliability and utility of simulation modeling.

Colorectal cancer screening with faecal immunochemical testing, sigmoidoscopy or colonoscopy: a microsimulation modelling study

OBJECTIVE

To estimate benefits and harms of different colorectal cancer screening strategies, stratified by (baseline) 15-year colorectal cancer risk.

DESIGN

Microsimulation modelling study using MIcrosimulation SCreening ANalysis-Colon (MISCAN-Colon).

SETTING

A parallel guideline committee (BMJ Rapid Recommendations) defined the time frame and screening interventions, including selection of outcome measures.

POPULATION

Norwegian men and women aged 50-79 years with varying 15-year colorectal cancer risk (1-7%).

COMPARISONS

Four screening strategies were compared with no screening: biennial or annual faecal immunochemical test (FIT) or single sigmoidoscopy or colonoscopy at 100% adherence.

MAIN OUTCOME MEASURES

Colorectal cancer mortality and incidence, burdens, and harms over 15 years of follow-up. The certainty of the evidence was assessed using the GRADE approach.

RESULTS

Over 15 years of follow-up, screening individuals aged 50-79 at 3% risk of colorectal cancer with annual FIT or single colonoscopy reduced colorectal cancer mortality by 6 per 1000 individuals. Single sigmoidoscopy and biennial FIT reduced it by 5 per 1000 individuals. Colonoscopy, sigmoidoscopy, and annual FIT reduced colorectal cancer incidence by 10, 8, and 4 per 1000 individuals, respectively. The estimated incidence reduction for biennial FIT was 1 per 1000 individuals. Serious harms were estimated to be between 3 per 1000 (biennial FIT) and 5 per 1000 individuals (colonoscopy); harms increased with older age. The absolute benefits of screening increased with increasing colorectal cancer risk, while harms were less affected by baseline risk. Results were sensitive to the setting defined by the guideline panel. Because of uncertainty associated with modelling assumptions, we applied a GRADE rating of low certainty evidence to all estimates.

CONCLUSIONS

Over a 15 year period, all screening strategies may reduce colorectal cancer mortality to a similar extent. Colonoscopy and sigmoidoscopy may also reduce colorectal cancer incidence, while FIT shows a smaller incidence reduction. Harms are rare and of similar magnitude for all screening strategies.

Treatment capacity required for full-scale implementation of lung cancer screening in the United States

BACKGROUND

Full-scale implementation of lung cancer screening in the United States will increase detection of early stages. This study was aimed at assessing the capacity required for treating those cancers.

METHODS

A well-established microsimulation model was extended with treatment data from the National Cancer Database. We assessed how treatment demand would change when implementing lung cancer screening in 2018. Three policies were assessed: 1) annual screening of current smokers and former smokers who quit fewer than 15 years ago, aged 55 to 80 years, with a smoking history of at least 30 pack-years (US Preventive Services Task Force [USPSTF] recommendations); 2) annual screening of current smokers and former smokers who quit fewer than 15 years ago, aged 55 to 77 years, with a smoking history of at least 30 pack-years (Centers for Medicare and Medicaid Services [CMS] recommendations); and 3) annual screening of current smokers and former smokers who quit fewer than 10 years ago, aged 55 to 75 years, with a smoking history of at least 40 pack-years (the most cost-effective policy in Ontario [Ontario]). The base-case screening adherence was a constant 50%. Sensitivity analyses assessed other adherence levels, including a linear buildup to 50% between 2018 and 2027.

RESULTS

The USPSTF policy would require 37.0% more lung cancer surgeries in 2015-2040 than no screening, 2.2% less radiotherapy, and 5.4% less chemotherapy; 5.7% more patients would require any therapy. The increase in surgical demand would be 96.1% in 2018, 46.0% in 2023, 38.3% in 2028, and 24.9% in 2040. Adherence strongly influenced results. By 2018, surgical demand would range from 52,619 (20% adherence) to 96,121 (80%). With a gradual buildup of adherence, the increase in surgical demand would be 9.6% in 2018, 38.3% in 2023, 42.0% in 2028, and 24.4% in 2040. Results for the CMS and Ontario policies were similar, although the changes in comparison with no screening were smaller.

CONCLUSIONS

Full-scale implementation of lung cancer screening causes a major increase in surgical demand, with a peak within the first 5 years. A gradual buildup of adherence can spread this peak over time. Careful surgical capacity planning is essential for successfully implementing screening.

Optimal age for screening colonoscopy: a modeling study

BACKGROUND AND AIMS

Recent guidelines on colorectal cancer (CRC) screening recommend starting screening earlier than before. We performed a simulation study to examine and compare the optimal ages to have once-only screening colonoscopy and repeated colonoscopies.

METHODS

A Markov model was set up using data from the German national screening colonoscopy registry to simulate the natural history of the adenoma-carcinoma process. CRC deaths and years of potential life lost (YPLL) for a hypothetical unscreened 50-year-old German population were estimated for a single screening colonoscopy or 2 or 3 screening colonoscopies with 10-year intervals at various ages.

RESULTS

One single screening colonoscopy performed between 50 and 65 years of age was expected to reduce CRC death by 49% to 69% and YPLL by 51% to 68%. An inverted U-shaped association was found between screening age and proportion of CRC deaths or YPLL prevented. The optimal age for once-only colonoscopy that yielded the highest reductions in YPLL was around 54 years for men and 56 years for women. Estimates were approximately 6 to 8 years higher when proportions of CRC deaths prevented were examined. For 2 or 3 screening colonoscopies, the optimal starting age fell to around 50 years or even younger for both genders.

CONCLUSIONS

Based on the YPLL estimates, in a high CRC incidence and high life expectancy country like Germany, the optimal age for once-only screening colonoscopy is around 55 years and possibly slightly younger for men than for women. When 2 or more screening colonoscopies are offered with 10-year intervals, screening should start at age 50 at the latest or possibly even younger for both genders.

Evidence-based sizing of non-inferiority trials using decision models

Background

There are significant challenges to the successful conduct of non-inferiority trials because they require large numbers to demonstrate that an alternative intervention is “not too much worse” than the standard. In this paper, we present a novel strategy for designing non-inferiority trials using an approach for determining the appropriate non-inferiority margin (δ), which explicitly balances the benefits of interventions in the two arms of the study (e.g. lower recurrence rate or better survival) with the burden of interventions (e.g. toxicity, pain), and early and late-term morbidity.

Methods

We use a decision analytic approach to simulate a trial using a fixed value for the trial outcome of interest (e.g. cancer incidence or recurrence) under the standard intervention (p_S) and systematically varying the incidence of the outcome in the alternative intervention (p_A). The non-inferiority margin, p_A – p_S = δ, is reached when the lower event rate of the standard therapy counterbalances the higher event rate but improved morbidity burden of the alternative. We consider the appropriate non-inferiority margin as the tipping point at which the quality-adjusted life-years saved in the two arms are equal.

Results

Using the European Polyp Surveillance non-inferiority trial as an example, our decision analytic approach suggests an appropriate non-inferiority margin, defined here as the difference between the two study arms in the 10-year risk of being diagnosed with colorectal cancer, of 0.42% rather than the 0.50% used to design the trial. The size of the non-inferiority margin was smaller for higher assumed burden of colonoscopies.

Conclusions

The example demonstrates that applying our proposed method appears feasible in real-world settings and offers the benefits of more explicit and rigorous quantification of the various considerations relevant for determining a non-inferiority margin and associated trial sample size.

Modeling in Colorectal Cancer Screening: Assessing External and Predictive Validity of MISCAN-Colon Microsimulation Model Using NORCCAP Trial Results

BACKGROUND

Microsimulation models are increasingly being used to inform colorectal cancer (CRC) screening recommendations. MISCAN-Colon is an example of such a model, used to inform the Dutch CRC screening program and US Preventive Services Task Force guidelines. Assessing the validity of these models is essential to provide transparency regarding their performance. In this study, we tested the external and predictive validity of MISCAN-Colon.

METHODS

We validated MISCAN-Colon using the Norwegian Colorectal Cancer Prevention (NORCCAP) trial, a randomized controlled trial that examined the effectiveness of once-only flexible sigmoidoscopy (FS) screening. We simulated the study population and design of the NORCCAP trial in MISCAN-Colon and compared 10- to 12-year model-predicted hazard ratios (HRs) for overall and distal CRC incidence and mortality to those observed. In addition, we compared the numbers of screen-detected neoplasia. Finally, we predicted the trial's future results to allow for the assessment of predictive validity.

RESULTS

MISCAN-Colon predicted an HR for overall CRC incidence (0.85), distal CRC incidence (0.82), overall CRC mortality (0.68), and distal CRC mortality (0.62). These were within the limits of the 95% confidence intervals of the NORCCAP trial results. Similar results were observed for the number of screen-detected cancers. The model significantly underestimated the number of screen-detected adenomas. Model-predicted HRs for CRC incidence and mortality up to 15- to 17-year follow-up were 0.84 and 0.72, respectively.

CONCLUSION

Although the underestimation of screen-detected adenomas requires further investigation, MISCAN-Colon is able to make a valid replication of the CRC incidence and mortality reduction of an FS screening trial, which suggests that it can be considered a useful tool to support decision making on CRC screening.

The colorectal cancer epidemic: challenges and opportunities for primary, secondary and tertiary prevention

Colorectal cancer (CRC) is both one of the most common and one of the most preventable cancers globally, with powerful but strongly missed potential for primary, secondary and tertiary prevention. CRC incidence has traditionally been the highest in affluent Western countries, but it is now increasing rapidly with economic development in many other parts of the world. CRC shares several main risk factors, such as smoking, excessive alcohol consumption, physical inactivity and being overweight, with other common diseases; therefore, primary prevention efforts to reduce these risk factors are expected to have multiple beneficial effects that extend beyond CRC prevention, and should have high public health impact. A sizeable reduction in the incidence and mortality of CRC can also be achieved by offering effective screening tests, such as faecal immunochemical tests, flexible sigmoidoscopy and colonoscopy, in organised screening programmes which have been implemented in an increasing number of countries. Countries with early and high uptake rates of effective screening have exhibited major declines in CRC incidence and mortality, in contrast to most other countries. Finally, increasing evidence shows that the prognosis and quality of life of CRC patients can be substantially improved by tertiary prevention measures, such as the administration of low-dose aspirin and the promotion of physical activity.

Rolling-out Screening Volume Affecting Compliance Rate and Waiting Time of FIT-based Colonoscopy

BACKGROUND AND STUDY AIMS

The population-based colorectal cancer screening program with fecal immunochemical test (FIT) from the inaugural period to the rolling-out period may create a higher demand for colonoscopies, but such a change has not been quantified. We intended to assess the change in the compliance rate and the waiting time (WT) for a colonoscopy and the associated geographic and institutional variations across the 2 periods.

MATERIALS AND METHODS

Data from the Taiwanese nationwide colorectal cancer screening program were analyzed. The data included a total of 46,235 FIT-positive cases of 1,258,560 tests in the inaugural period (2004 to 2009) and 270,700 FIT-positive cases of 3,723,789 tests in the rolling-out period (2010 to 2013). The compliance rate and WT for colonoscopy after positive FIT was ascertained and compared between the 2 periods.

RESULTS

The rolling-out period resulted in a decline of 16.0% for compliance rate and yielded an additional 1,778,499 waiting days with variation across geography and institution. After adjusting for relevant factors, a decrease in compliance rate by 8.5% and an increase of 714,648 waiting days were still noted. In the rolling-out period, a remarkable decline in compliance rate by 9.8% was found in middle Taiwan, and the longest WT (1,260,109 d) was observed in southern Taiwan. Screening at public health centers led to a 19% decrease in compliance rate and an increase of 2,546,746 waiting days.

CONCLUSIONS

The decrease in compliance rate and an increase in the WT with variation across geography and institution resulting from the increased volume of rolling-out FIT screening provide an insight into optimal resource allocation of clinical capacity for colonoscopy.

Screening Women Aged 50-59 for CRC Using Fecal Occult Blood Test Produces Outcomes Similar to Men Undergoing Screening Colonoscopy

BACKGROUND

Average-risk women aged 50-59 years have a lower incidence and mortality of colorectal cancer relative to age-matched men, calling into question the benefit of screening colonoscopy in this age group.

AIMS

We aimed to determine whether FOBT is an effective initial screening test in 50-59-year-old women.

METHODS

We conducted a cross-sectional study using a computerized endoscopic report generator. We identified 320,906 individuals who had average-risk screening colonoscopy and 32,369 who had colonoscopy for positive FOBT. The primary outcome was the positive predictive value (PPV) of FOBT for large polyp(s) greater than 9 mm, as a surrogate for advanced neoplasia.

RESULTS

Among patients aged 50-59 years undergoing screening colonoscopy, men were more likely than women to have large polyps (6.3 vs 4.2%, p < 0.0001). Black women undergoing screening colonoscopy had higher rates of large polyps compared to non-Black women. The PPV in FOBT-positive men aged 50-54 (11.5%) and 55-59 (14.4%) was higher than in women aged 50-54 (6.1%) and 55-59 (5.4%). Despite this lower PPV, women aged 50-54 with a positive FOBT had a similar rate of large polyps as 50-54-year-old men undergoing screening colonoscopy (6.1 vs 6.3%, p = 0.626).

CONCLUSIONS

CRC screening with FOBT identifies 50-59-year-old men and women with a higher risk of large polyps. Since younger women have a lower risk of large polyps than men, screening with FOBT in 50-59-year-old non-Black women could be an effective screening strategy, with outcomes similar to the use of screening colonoscopy in 50-59-year-old men.

Cost-effectiveness and budget impact analyses of a colorectal cancer screening programme in a high adenoma prevalence scenario using MISCAN-Colon microsimulation model

Background

The Basque Colorectal Cancer Screening Programme began in 2009 and the implementation has been complete since 2013. Faecal immunological testing was used for screening in individuals between 50 and 69 years old. Colorectal Cancer in Basque country is characterized by unusual epidemiological features given that Colorectal Cancer incidence is similar to other European countries while adenoma prevalence is higher. The object of our study was to economically evaluate the programme via cost-effectiveness and budget impact analyses with microsimulation models.

Methods

We applied the Microsimulation Screening Analysis (MISCAN)-Colon model to predict trends in Colorectal Cancer incidence and mortality and to quantify the short- and long-term effects and costs of the Basque Colorectal Cancer Screening Programme. The model was calibrated to the Basque demographics in 2008 and age-specific Colorectal Cancer incidence data in the Basque Cancer Registry from 2005 to 2008 before the screening begun. The model was also calibrated to the high adenoma prevalence observed for the Basque population in a previously published study. The multi-cohort approach used in the model included all the cohorts in the programme during 30 years of implementation, with lifetime follow-up. Unit costs were obtained from the Basque Health Service and both cost-effectiveness analysis and budget impact analysis were carried out.

Results

The goodness-of-fit of the model adaptation to observed programme data was evidence of validation. In the cost-effectiveness analysis, the savings from treatment were larger than the added costs due to screening. Thus, the Basque programme was dominant compared to no screening, as life expectancy increased by 29.3 days per person. The savings in the budget analysis appeared 10 years after the complete implementation of the programme. The average annual budget was €73.4 million from year 2023 onwards.

Conclusions

This economic evaluation showed a screening intervention with a major health gain that also produced net savings when a long follow-up was used to capture the late economic benefit. The number of colonoscopies required was high but remain within the capacity of the Basque Health Service. So far in Europe, no other population Colorectal Cancer screening programme has been evaluated by budget impact analysis.

Electronic supplementary material

The online version of this article (10.1186/s12885-018-4362-1) contains supplementary material, which is available to authorized users.

Variation of diagnostic performance of fecal immunochemical testing for hemoglobin by sex and age: results from a large screening cohort

Objective

Fecal immunochemical tests (FITs) for hemoglobin in stool are increasingly used for colorectal cancer screening. Reported sensitivities and specificities have strongly varied between studies, but it is unclear to what extent such variation reflects differences between tests or between study population characteristics. We aimed to evaluate the key parameters of FIT performance for detecting advanced neoplasia (AN) according to sex and age.

Methods

Sex- and age-specific sensitivity, specificity, positive predictive values (PPVs) and negative predictive values (NPVs) for detecting AN of a quantitative FIT (FOB Gold®) were evaluated among 3211 men and women aged 50–79 years who underwent screening colonoscopy in Germany.

Results

At the cutoff recommended by the manufacturer (17 µg hemoglobin/g feces), sensitivity was higher (51.2% versus 34.7%, p=0.004) and specificity was lower (91.0% versus 94.8%, p<0.001) among 65–79 year-old participants compared with 50–64 year-old participants. PPVs and NPVs did not differ significantly between age groups. However, higher NPVs were observed among women compared with men (94.7% versus 92.5%, p=0.015). Specificity was also higher among women compared with men (94.7% versus 92.3%, p=0.007), while there was only a little variation in sensitivity (40.3% versus 41.8%, p=0.789) according to sex. In joint stratification by both factors, sensitivity ranged from 34.1% (95% CI 24.2%–45.2%) in 50–64 year-old women to 51.4% (95% CI 39.3%–63.3%) in 65–79 year-old men (p=0.029). The observed age and sex differences were highly consistent across a wide range of alternative cutoffs from 10 to 50 µg hemoglobin/g feces.

Conclusion

There are major differences in diagnostic performance parameters according to sex and age, which should receive careful attention in the interpretation and comparison of results of FIT-based colorectal cancer screening studies.

Lung cancer screening: latest developments and unanswered questions

The US National Lung Screening Trial showed that individuals randomly assigned to screening with low-dose CT scans had 20% lower lung cancer mortality than did those screened with conventional chest radiography. On the basis of a review of the literature and a modelling study, the US Preventive Services Task Force recommends annual screening for lung cancer for individuals aged 55-80 years who have a 30 pack-year smoking history and either currently smoke or quit smoking within the past 15 years. However, the balance between benefits and harms of lung cancer screening is still greatly debated. The large number of false-positive results and the potential for overdiagnosis are causes for concern. Some investigators suggest the ratio between benefits and harms could be improved through various means. Nevertheless, many questions remain with regard to the implementation of lung cancer screening. This paper highlights the latest developments in CT lung cancer screening and provides an overview of the main unanswered questions.

Impact of adenoma detection on the benefit of faecal testing vs. colonoscopy for colorectal cancer

Colonoscopy quality, as measured by adenoma detection rates, varies widely across providers and is inversely related to patients' post-colonoscopy cancer risk. This has unknown consequences for the benefits of faecal immunochemical testing (FIT) vs. primary colonoscopy screening for colorectal cancer. Using an established microsimulation model, we predicted the lifetime colorectal cancer incidence and mortality benefits of annual FIT vs. 10-yearly colonoscopy screening at differing ADR levels (quintiles; averages 15.3-38.7%), with colonoscopy performance assumptions estimated from community-based data on physician ADRs and patients' post-colonoscopy risk of cancer. For patients receiving FIT screening with follow-up colonoscopy by physicians from the highest ADR quintile, simulated lifetime cancer incidence and mortality were 28.8 and 5.4 per 1,000, respectively, vs. 20.6 and 4.4 for primary colonoscopy screening (risk ratios, RR = 1.40; 95% probability interval (PI), 1.19-1.71 for incidence, and RR = 1.22; 95%PI, 1.02-1.54 for mortality). With every 5% point ADR decrease, lifetime cancer incidence was predicted to increase on average 9.0% for FIT vs. 12.3% for colonoscopy, and mortality increased 9.9% vs. 13.3%. In ADR quintile 1, simulated mortality was lower for FIT than colonoscopy screening (10.1 vs. 11.8; RR = 0.85; 95%PI, 0.83-0.90), while incidences were more similar. This suggests that relative cancer incidence and mortality reductions for FIT vs. colonoscopy screening may differ by ADR, with fewer predicted deaths with colonoscopy screening in higher ADR settings and fewer deaths with annual FIT screening in lower ADR settings.

Association Between Concentrations of Hemoglobin Determined by Fecal Immunochemical Tests and Long-term Development of Advanced Colorectal Neoplasia

BACKGROUND & AIMS

Colorectal cancer (CRC) screening using quantitative fecal immunochemical tests (FITs) is rapidly gaining ground worldwide. FITs are invariably used in a dichotomous manner using pre-specified cut-off values. To optimize FIT-based screening programs, we investigated the association between fecal hemoglobin (_fHb) concentrations below the FIT cut-off value and later development of colorectal advanced neoplasia (AN).

METHODS

We analyzed data collected from a population-based study of 9561 average-risk subjects (50-74 years old) in the Netherlands who were offered 4 rounds of FIT screening for CRC from November 2006 through December 2014. We analyzed data from 7663 participants screened at least once and found to have a negative FIT result at baseline (below the cut-off value of 10 μg Hb/ g feces). Participants were followed for a median of 4.7 years (interquartile range, 2.0-6.1 years); CRCs diagnosed outside the screening program were identified from the Dutch Comprehensive Cancer Centre database. Hazard ratios for AN were determined using Cox proportional hazard regression analyses. Logistic regression techniques were used to calculate risks of AN after consecutive fHb concentrations below the cut-off value.

RESULTS

After 8 years of follow-up, participants with baseline concentrations of 8-10 μg fHb/g had a higher cumulative incidence of AN (33%) than participants with 0 μg fHb/g (5%) (P < .001). Multi-variate hazard ratios increased from 1.2 for subjects with concentrations of 0-2 μg fHb/g to 8.2 for subjects with concentrations of 8-10 μg fHb/g (P < .001). Participants with 2 consecutive fHb concentrations of 8 μg Hb/g had a 14-fold increase in risk of AN compared with participants with 2 consecutive fHb concentrations of 0 μg Hb/g (P < .001).

CONCLUSIONS

In a population-based study of average-risk individuals with a FIT result below the cut-off value, we associated baseline concentrations of 8-10 μg fHb/g with an increased risk of AN compared with baseline concentrations of 0 μg fHb/g. Baseline and consecutive fHb concentrations are independent predictors for incident AN. This information might be used in designing personalized strategies for population-based CRC screening and reduce unnecessary repeat tests. Trialregister.nl no: first round, NTR1096; second round and additional invitees, NTR1512.

Cost-effectiveness of the faecal immunochemical test at a range of positivity thresholds compared with the guaiac faecal occult blood test in the NHS Bowel Cancer Screening Programme in England

OBJECTIVES

Through the National Health Service (NHS) Bowel Cancer Screening Programme (BCSP), men and women in England aged between 60 and 74 years are invited for colorectal cancer (CRC) screening every 2 years using the guaiac faecal occult blood test (gFOBT). The aim of this analysis was to estimate the cost-utility of the faecal immunochemical test for haemoglobin (FIT) compared with gFOBT for a cohort beginning screening aged 60 years at a range of FIT positivity thresholds.

DESIGN

We constructed a cohort-based Markov state transition model of CRC disease progression and screening. Screening uptake, detection, adverse event, mortality and cost data were taken from BCSP data and national sources, including a recent large pilot study of FIT screening in the BCSP.

RESULTS

Our results suggest that FIT is cost-effective compared with gFOBT at all thresholds, resulting in cost savings and quality-adjusted life years (QALYs) gained over a lifetime time horizon. FIT was cost-saving (p<0.001) and resulted in QALY gains of 0.014 (95% CI 0.012 to 0.017) at the base case threshold of 180 µg Hb/g faeces. Greater health gains and cost savings were achieved as the FIT threshold was decreased due to savings in cancer management costs. However, at lower thresholds, FIT was also associated with more colonoscopies (increasing from 32 additional colonoscopies per 1000 people invited for screening for FIT 180 µg Hb/g faeces to 421 additional colonoscopies per 1000 people invited for screening for FIT 20 µg Hb/g faeces over a 40-year time horizon). Parameter uncertainty had limited impact on the conclusions.

CONCLUSIONS

This is the first published economic analysis of FIT screening in England using data directly comparing FIT with gFOBT in the NHS BSCP. These results for a cohort starting screening aged 60 years suggest that FIT is highly cost-effective at all thresholds considered. Further modelling is needed to estimate economic outcomes for screening across all age cohorts simultaneously.

[Colorectal cancer screening programme in Aragon (Spain): preliminary results]

OBJECTIVE

To describe preliminary findings from the colorectal cancer screening programme in Aragon (Spain) to evaluate its implementation.

METHODS

We have collected data from the first year of the program (2014) based on faecal occult blood immunochemical (FOBTi) test in patients 60-69 years old. We report "indicators" defined by the "Red Nacional de Cribado".

RESULTS

Invited population after exclusions: 12,518. Program participation rate: 45.28% (95%CI: 44.41-46.15). Inadequate tests: 0.21% (95%CI: 0.12-0.37); positive FOBTi test 10.75% (95%CI: 9.97-11.58) and colonoscopy acceptance 95.07% (95%CI: 93.04-96.52). Colonoscopy was appropriate and complete in 97.58% (95%CI: 95.98-98.55) of cases. The high- and low-risk adenoma detection rates were 14.7‰ (95%CI: 11.9-18.2) and 5.55‰ (95%CI: 3.9-7.8) respectively. The positive predictive value for any adenoma was 58.55% (95%CI: 54.49-62.49) and for invasive cancer was 5.36% (95%CI: 3.8-7.51).

CONCLUSION

The indicator analysis of the ongoing programme suggests the programme is being implemented correctly in our community.

Selecting a Cut-off for Colorectal Cancer Screening With a Fecal Immunochemical Test

OBJECTIVES

Fecal immunochemical tests (FITs) for hemoglobin (Hb) are increasingly used for colorectal cancer (CRC) screening. However, cut-offs for defining test positivity are varying widely. We aimed to evaluate the impact of cut-off selection on key indicators of diagnostic performance in a true screening setting.

METHODS

We evaluated diagnostic performance of FOB Gold, a widely used quantitative FIT, for detecting advanced neoplasms (AN) across a wide range of possible cut-offs among 1822 participants of screening colonoscopy aged 50-79 years in Germany.

RESULTS

The positive predictive value (PPV) for detecting AN showed a very steep increase with increasing cut-off up to 35.2% (95% CI 29.9-40.9%) at a cut-off of 9 μg Hb/g feces at which sensitivity and specificity were 48.8% (95% CI 42.1-55.6%) and 88.5% (95% CI 86.8-89.9%), respectively. A further moderate increase of PPV up to 56.9% (95% CI 47.8-65.5%), along with a major decrease in sensitivity was observed when gradually increasing the cut-off to 25 μg Hb/g feces at which sensitivity and specificity were 31.9% (95% CI 25.9-38.5%) and 96.9% (95% CI 95.9-97.6%), respectively. Further increases of the cut-off hardly affected PPV and specificity, but went along with further relevant decline in sensitivity.

CONCLUSIONS

Our study illustrates delineation of a range of meaningful cut-offs (here: 9-25 μg Hb/g feces) according to expected diagnostic yield in a true screening setting. Selecting a cut-off within or beyond this range should consider characteristics of the specific target population, such as AN prevalence or available colonoscopy capacity.

Evaluation of the colorectal cancer screening Programme in the Basque Country (Spain) and its effectiveness based on the Miscan-colon model

Abstract

The population-based Basque Colorectal Cancer (CRC) Screening Programme started in 2009 with a biennial immunochemical quantitative test (FIT) biennial and colonoscopy under sedation in positive cases. The population target of 586,700 residents was from 50 to 69 years old and the total coverage was reached at the beginning of 2014. The aim of our study was to determine possible scenarios in terms of incidence, mortality and reduction of Life-years-Lost (L-y-L) in the medium and long term of CRC.

Methods

Invitations were sent out by the Programme from 2009 to 2014, with combined organizational strategies. Simulation was done by MISCAN-colon (Microsimulation Screening Analysis) over 30 years comparing the results of screening vs no-screening, taking the population-based Cancer Registry into account. Lifetime population and real data from the Programme were used from 2008 to 2012. The model was run differentially for men and women.

Results

924,416 invitations were sent out from 2009 to 2014. The average participation rate was 68.4%, CRC detection rate was 3.4% and the Advanced Adenoma detection rate was 24.0‰, with differences observed in sex and age. Future scenarios showed a higher decrease of incidence (17.2% vs 14.7%), mortality (28.1% vs 22.4%) and L-y-L (22.6% vs 18.4%) in men than women in 2030.

Conclusions

The Basque Country CRC Programme results are aligned to its strategy and comparable to other programmes. MISCAN model was found to be a useful tool to predict the benefits of the programme in the future. The effectiveness of the Programme has not been formally established as case control studies are required to determine long term benefits from the screening strategy.

Real-Time Monitoring of Results During First Year of Dutch Colorectal Cancer Screening Program and Optimization by Altering Fecal Immunochemical Test Cut-Off Levels

BACKGROUND & AIMS

After careful pilot studies and planning, the national screening program for colorectal cancer (CRC), with biennial fecal immunochemical tests (FITs), was initiated in The Netherlands in 2014. A national information system for real-time monitoring was developed to allow for timely evaluation. Data were collected from the first year of this screening program to determine the importance of planning and monitoring for optimal screening program performance.

METHODS

The national information system of the CRC screening program kept track of the number of invitations sent in 2014, FIT kits returned, and colonoscopies performed. Age-adjusted rates of participation, the number of positive test results, and positive predictive values (PPVs) for advanced neoplasia were determined weekly, quarterly, and yearly.

RESULTS

In 2014, there were 741,914 persons invited for FIT; of these, 529,056 (71.3%; 95% CI, 71.2%-71.4%) participated. A few months into the program, real-time monitoring showed that rates of participation and positive test results (10.6%; 95% CI, 10.5%-10.8%) were higher than predicted and the PPV was lower (42.1%; 95% CI, 41.3%-42.9%) than predicted based on pilot studies. To reduce the burden of unnecessary colonoscopies and alleviate colonoscopy capacity, the cut-off level for a positive FIT result was increased from 15 to 47 μg Hb/g feces halfway through 2014. This adjustment decreased the percentage of positive test results to 6.7% (95% CI, 6.6%-6.8%) and increased the PPV to 49.1% (95% CI, 48.3%-49.9%). In total, the first year of the Dutch screening program resulted in the detection of 2483 cancers and 12,030 advanced adenomas.

CONCLUSIONS

Close monitoring of the implementation of the Dutch national CRC screening program allowed for instant adjustment of the FIT cut-off levels to optimize program performance.

The cost of colorectal cancer according to the TNM stage

INTRODUCTION

The aim of this study was to measure the cost of treatment of colorectal cancer in the Basque public health system according to the clinical stage.

METHODS

We retrospectively collected demographic data, clinical data and resource use of a sample of 529 patients. For stagesi toiii the initial and follow-up costs were measured. The calculation of cost for stageiv combined generalized linear models to relate the cost to the duration of follow-up based on parametric survival analysis. Unit costs were obtained from the analytical accounting system of the Basque Health Service.

RESULTS

The sample included 110 patients with stagei, 171 with stageii, 158 with stageiii and 90 with stageiv colorectal cancer. The initial total cost per patient was 8,644€ for stagei, 12,675€ for stageii and 13,034€ for stageiii. The main component was hospitalization cost. Calculated by extrapolation for stageiv mean survival was 1.27years. Its average annual cost was 22,403€, and 24,509€ to death. The total annual cost for colorectal cancer extrapolated to the whole Spanish health system was 623.9million€.

CONCLUSIONS

The economic burden of colorectal cancer is important and should be taken into account in decision-making. The combination of generalized linear models and survival analysis allows estimation of the cost of metastatic stage.

The validation of electronic health records in accurately identifying patients eligible for colorectal cancer screening in safety net clinics

BACKGROUND

While electronic health records (EHRs) play a key role in increasing colorectal cancer (CRC) screening by identifying individuals who are overdue, important shortfalls remain.

OBJECTIVES

As part of the Strategies and Opportunities to STOP Colon Cancer (STOP CRC) study, we assessed the accuracy of EHR codes in identifying patients eligible for CRC screening.

METHODS

We selected a stratified random sample of 800 study participants from 26 participating clinics, in the Pacific Northwest region of the USA. We compared data obtained through codes in the EHR to conduct a manual chart audit. A trained chart abstractor completed the abstraction of eligible and ineligible patients.

RESULTS

Of 520 individuals in need of CRC screening, identified via the EHR, 459 were confirmed through chart review (positive predictive value = 88%). Of 280 individuals flagged as up-to-date in their screening per EHR data, 269 were confirmed through chart review (negative predictive value = 96%). Among the 61 patients incorrectly classified as eligible, 83.6% of disagreements were due to evidence of a prior colonoscopy or referral that was not captured in recognizable fields in the EHR.

CONCLUSIONS

Our findings highlight importance of better capture of past screening events in the EHR. While the need for better population-based data is not unique to CRC screening, it provides an important example of the use of population-based data not only for tracking care, but also for delivering interventions.