Effectiveness and Cost-Effectiveness of Colorectal Cancer Screening With a Blood Test That Meets the Centers for Medicare & Medicaid Services Coverage Decision.

BACKGROUND & AIMS: A blood-based colorectal cancer (CRC) screening test may increase screening participation. However, blood tests may be less effective than current guideline-endorsed options. The Centers for Medicare & Medicaid Services (CMS) covers blood tests with sensitivity of at least 74% for detection of CRC and specificity of at least 90%. In this study, we investigate whether a blood test that meets these criteria is cost-effective. METHODS: Three microsimulation models for CRC (MISCAN-Colon, CRC-SPIN, and SimCRC) were used to estimate the effectiveness and cost-effectiveness of triennial blood-based screening (from ages 45 to 75 years) compared to no screening, annual fecal immunochemical testing (FIT), triennial stool DNA testing combined with an FIT assay, and colonoscopy screening every 10 years. The CMS coverage criteria were used as performance characteristics of the hypothetical blood test. We varied screening ages, test performance characteristics, and screening uptake in a sensitivity analysis. RESULTS: Without screening, the models predicted 77-88 CRC cases and 32-36 CRC deaths per 1000 individuals, costing $5.3-$5.8 million. Compared to no screening, blood-based screening was cost-effective, with an additional cost of $25,600-$43,700 per quality-adjusted life-year gained (QALYG). However, compared to FIT, triennial stool DNA testing combined with FIT, and colonoscopy, blood-based screening was not cost-effective, with both a decrease in QALYG and an increase in costs. FIT remained more effective (+5-24 QALYG) and less costly (-$3.2 to -$3.5 million) than blood-based screening even when uptake of blood-based screening was 20 percentage points higher than uptake of FIT. CONCLUSION: Even with higher screening uptake, triennial blood-based screening, with the CMS-specified minimum performance sensitivity of 74% and specificity of 90%, was not projected to be cost-effective compared with established strategies for colorectal cancer screening.

Effects on Cancer Prevention from the COVID-19 Pandemic.

The COVID-19 pandemic led to disruption of health services around the world, including cancer services. We carried out a narrative review of the effect of the pandemic on cancer prevention services, including screening. Services were severely affected in the early months of the pandemic, and in some areas are still recovering. Large numbers of additional cancers or additional late-stage cancers have been predicted to arise over the coming years as a result of this disruption. To minimize the effects on cancer outcomes, it is necessary to return as quickly as possible to prepandemic levels of screening and prevention activity or indeed to exceed these levels. The recovery of services should address health inequalities.

Rationale for organized Colorectal cancer screening programs.

Colorectal cancer (CRC) is a major health problem and it is expected that the number of persons diagnosed with CRC and CRC-related deaths will continue to increase. However, recent years have shown reductions in CRC incidence and mortality particularly among individuals aged 50 years and older which can be attributed to screening, improvements in patients' management, closer adherence to treatment guideline recommendations and a higher utilization of curative surgery, chemotherapy and radiotherapy. The International Agency for Research on Cancer has concluded that there has been sufficient evidence that biennially screening using a stool-test or once-only endoscopy screening reduces CRC-related mortality. In Europe, between 2008 and 2018, nine countries have successfully implemented a population-based organized program and another six are in the roll-out phase. Population-based organized programs show higher screening participation rates and lower lack of compliance to follow-up testing after a positive screen test compared to opportunistic screening. Moreover, organized programs aim to provide high quality screening thereby reducing the risk of the harms of screening, including over-screening, and complications of screening, and poor follow-up of those who test positive. We describe how population-based organized CRC screening programs are preferred, since they reflect a more appropriate utilization of available resources, reduce inequities in access, and can integrate interventions addressing barriers to screening at the individual and health system levels.

Interval post-colonoscopy colorectal cancer following a negative colonoscopy in a fecal immunochemical test-based screening program.

BACKGROUND: In the Dutch colorectal (CRC) screening program, fecal immunochemical test (FIT)-positive individuals are referred for colonoscopy. If no relevant findings are detected at colonoscopy, individuals are reinvited for FIT screening after 10 years. We aimed to assess CRC risk after a negative colonoscopy in FIT-positive individuals. METHODS: In this cross-sectional cohort study, data were extracted from the Dutch national screening information system. Participants with a positive FIT followed by a negative colonoscopy between 2014 and 2018 were included. A negative colonoscopy was defined as a colonoscopy during which no more than one nonvillous, nonproximal adenoma < 10 mm or serrated polyp < 10 mm was found. The main outcome was interval post-colonoscopy CRC (iPCCRC) risk. iPCCRC risk was reviewed against the risk of interval CRC after a negative FIT (FIT IC) with a 2-year screening interval. RESULTS: 35 052 FIT-positive participants had a negative colonoscopy and 24 iPCCRCs were diagnosed, resulting in an iPCCRC risk of 6.85 (95 %CI 4.60-10.19) per 10 000 individuals after a median follow-up of 1.4 years. After 2.5 years of follow-up, age-adjusted iPCCRC risk was approximately equal to FIT IC risk at 2 years. CONCLUSION: Risk of iPCCRC within a FIT-based CRC screening program was low during the first years after colonos-copy but, after 2.5 years, was the same as the risk in FIT-negative individuals at 2 years, when they are reinvited for screening. Colonoscopy quality may therefore require further improvement and FIT screening interval may need to be reduced after negative colonoscopy.

Personalised colorectal cancer screening strategies: Information needs of the target population.

Prior faecal Hemoglobin (f-Hb) concentrations of a negative fecal immunochemical test (FIT) can be used for risk stratification in colorectal cancer (CRC) screening. Individuals with higher f-Hb concentrations may benefit from a shorter screening interval (1 year), whereas individuals with undetectable f-Hb concentrations could benefit from a longer screening interval (3 year). Individuals' views on personalised CRC screening and information needed to make a well-informed decision is unknown. We conducted three semi-structured focus groups among individuals eligible for CRC screening (i.e. men and women aged 55 to 75) in the Netherlands. Thematic analysis was used to analyse participants' information need on personalised CRC screening strategies. Fourteen individuals took part. The majority were positive about CRC screening and indicated that they would participate in personalised CRC screening. The rationale for a longer interval among those at lowest risk was, however, unclear for many. The preferred information on individual risk was variable: ranging from full information to only information on the personalised strategy without mentioning the risk. It was not possible to address everyone's need with a single approach. Additional communications, e.g. public media campaigns, billboards, videos on social media, were also suggested as necessary. This study showed that preferences on receiving information on individual CRC risk varied substantially and no consensus was reached. Introducing a personalised screening programme will require careful communication, particularly around the rationale for the strategy, and a layered approach to deliver information.

Colorectal Cancer Stage Distribution at First and Repeat Fecal Immunochemical Test Screening.

BACKGROUND & AIMS: For colorectal cancer (CRC) screening to be effective, it is important that screen-detected cancers are found at an early stage. Studies on stage distribution of screen-detected CRC at repeat screening of large population-based fecal immunochemical test (FIT)-based screening programs and the impact of FIT cut-off values on staging currently are lacking. METHODS: We obtained data for FIT-positive participants (FIT cut-off, 47 µg hemoglobin/g feces) at their first or second (ie, repeat) screening from the Dutch National Screening Database from 2014 to 2018. Tumor characteristics were acquired through linkage with The Netherlands Cancer Registry. We compared stage at diagnosis (I-II vs III-IV) of CRCs detected at a first or second screening. In addition, we analyzed the hypothetical yield and stage distribution of CRC for different FIT cut-off values up to 250 µg hemoglobin/g feces. RESULTS: At the first and second screenings, respectively, 15,755 and 3304 CRCs were detected. CRCs detected at the first or second screening were equally likely to be stages I to II (66.5% vs 67.7%; relative risk, 1.02; 95% CI, 1.00-1.05). A hypothetical increase of the FIT cut-off value from 47 µg to 250 µg resulted in a reduction of detected CRCs by 88.3% and 79.0% at the first or second screening, respectively. Even then, the majority of detected CRCs (63%-64%) still would be diagnosed at stages I to II. CONCLUSIONS: FIT-based screening is effective in downstaging CRC, and also at repeat screening. Increasingly, the FIT cut-off level has a limited impact on the stage distribution of detected CRCs, although it greatly affects CRC detection and thus is important to keep low.

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.

Socio-demographic and cultural factors related to non-participation in the Dutch colorectal cancer screening programme.

BACKGROUND: High participation rates are essential for a screening programme to be beneficial. To reach non-participants in a targeted manner, insight in characteristics of non-participants is needed. We investigated demographic differences between participants and non-participants in the Dutch faecal immunochemical test-based colorectal cancer (CRC) screening programme. METHODS: In this population-based cohort study, we included all invitees for CRC screening in 2018 and 2019. Participation status, birth year, and sex were extracted from the Dutch national screening information system and linked to demographic characteristics from Statistics Netherlands, including migration background, level of education, socioeconomic category, household composition, and household income. A multivariable logistic regression was used to assess the association between demographic factors and participation. RESULTS: A total of 4,383,861 individuals were invited for CRC screening in 2018 and 2019, of which 3,170,349 (72.3%) participated. Individuals were less likely to participate when they were single and/or living with others (single with other residents versus couple: odds ratio [OR] 0.34, 95% confidence interval [CI]: 0.31-0.38), had a migration background (e.g. Moroccan migrant versus Dutch background: OR 0.43, 95% CI: 0.42-0.44), or had a low income (lowest versus highest quintile: OR 0.45, 95% CI: 0.44-0.45). Although to a lesser extent, non-participation was also significantly associated with being male, being younger, receiving social welfare benefits and having a low level of education. CONCLUSION: We found that individuals who were single and/or living with others, immigrants from Morocco or individuals with low income were the least likely to participate in the Dutch CRC screening programme. Targeted interventions are needed to minimise inequities in CRC screening.

Impact of delayed screening invitations on screen-detected and interval cancers in the Dutch colorectal cancer screening programme: individual-level data analysis.

OBJECTIVE: To assess the impact of delayed invitation on screen-detected and interval colorectal cancers (CRC) within a faecal immunochemical testing (FIT)-based CRC screening programme. DESIGN: All individuals that participated in 2017 and 2018 with a negative FIT and were eligible for CRC screening in 2019 and 2020 were included using individual-level data. Multivariable logistic regression analyses were used to assess the association between either the different time periods (ie, 'before', 'during' and 'after' the first COVID-19 wave) or the invitation interval on screen-detected and interval CRCs. RESULTS: Positive predictive value for advanced neoplasia (AN) was slightly lower during (OR=0.91) and after (OR=0.95) the first COVID-19 wave, but no significant difference was observed for the different invitation intervals. Out of all individuals that previously tested negative, 84 (0.004%) had an interval CRC beyond the 24 months since their last invitation. The time period of invitation as well as the extended invitation interval was not associated with detection rates for AN and interval CRC rate. CONCLUSION: The impact of the first COVID-19 wave on screening yield was modest. A very small proportion of the FIT negatives had an interval CRC possibly due to an extended interval, which potentially could have been prevented if they had received the invitation earlier. Nonetheless, no increase in interval CRC rate was observed, indicating that an extended invitation interval up to 30 months had no negative impact on the performance of the CRC screening programme and a modest extension of the invitation interval seems an appropriate intervention.

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.

Factors associated with interval colorectal cancer after negative FIT: Results of two screening rounds in the Dutch FIT-based CRC screening program.

The interval colorectal cancer (CRC) rate after negative fecal immunochemical testing (FIT) is an important quality indicator of CRC screening programs. We analyzed the outcomes of two rounds of the FIT-based CRC screening program in the Netherlands, using data from individuals who participated in FIT-screening from 2014 to 2017. Data of individuals with one prior negative FIT (first round) or two prior negative FITs (first and second round) were included. Outcomes included the incidence of interval CRC in FIT-negative participants (<47 µg Hb/g feces [µg/g]), FIT-sensitivity, and the probability of detecting an interval CRC by fecal hemoglobin concentration (f-Hb). FIT-sensitivity was estimated using the detection method and the proportional incidence method (based on expected CRC incidence). Logistic regression analysis was performed to estimate whether f-Hb affects probability of detecting interval CRC, adjusted for sex- and age-differences. Incidence of interval CRC was 10.4 per 10 000 participants after the first and 9.6 after the second screening round. FIT-sensitivity based on the detection method was 84.4% (95%CI 83.8-85.0) in the first and 73.5% (95% CI 71.8-75.2) in the second screening round. The proportional incidence method resulted in a FIT-sensitivity of 76.4% (95%CI 73.3-79.6) in the first and 79.1% (95%CI 73.7-85.3) in the second screening round. After one negative FIT, participants with f-Hb just below the cut-off (>40-46.9 µg/g) had a higher probability of detecting an interval CRC (OR 16.9; 95%CI: 14.0-20.4) than had participants with unmeasurable f-Hb (0-2.6 µg/g). After two screening rounds, the odds ratio for interval CRC was 12.0 (95%CI: 7.8-17.6) for participants with f-Hb just below the cut-off compared with participants with unmeasurable f-Hb. After both screening rounds, the Dutch CRC screening program had a low incidence of interval CRC and an associated high FIT-sensitivity. Our findings suggest there is a potential for further optimizing CRC screening programs with the use of risk-stratified CRC screening based on prior f-Hb.

Faecal occult blood loss accurately predicts future detection of colorectal cancer. A prognostic model.

OBJECTIVES: To examine the prognostic potential of repeated faecal haemoglobin (F-Hb) concentration measurements in faecal immunochemical test (FIT)-based screening for colorectal cancer (CRC). DESIGN: Prognostic model. SETTING: Dutch biennial FIT-based screening programme during 2014-2018. PARTICIPANTS: 265 881 participants completing three rounds of FIT, with negative test results (F-Hb <47 µg Hb/g faeces) in rounds 1 and 2. INTERVENTIONS: Colonoscopy follow-up in participants with a positive FIT (F-Hb ≥47 µg Hb/g faeces). MAIN OUTCOMES: We evaluated prognostic models for detecting advanced neoplasia (AN) and CRC in round 3, with as predictors, participant age, sex, F-Hb in rounds 1 and 2, and categories/combinations/non-linear transformations of F-Hb. Primary evaluation criteria included: risk prediction accuracy (calibration), discrimination of participants with versus without AN or CRC (optimism-adjusted C-statistics, range 0.5-1.0), the degree of risk stratification and C-statistics in external validation. RESULTS: Among study participants, 8806 (3.3%) had a positive FIT result, 3254 (1.2%) had AN detected and 557 (0.2%) had cancer. F-Hb concentrations in rounds 1 and 2 were the strongest outcome predictors, with adjusted ORs of up to 9.4 (95% CI 7.5 to 11.7) for the highest F-Hb category. Risk predictions matched the observed risk for most participants (calibration intercept -0.008 to -0.099; slope 0.982-0.998), and discriminated participants with versus without AN or CRC with C-statistics of 0.78 (95% CI 0.77 to 0.79) and 0.73 (95% CI 0.71 to 0.75), respectively. The predicted risk ranged from 0.4% to 36.7% for AN and from 0.0% to 5.5% for CRC across participants. In external validation, the model retained similar discrimination accuracy for AN (C-statistic 0.77, 95% CI 0.66 to 0.87) and CRC (C-statistic 0.78, 95% CI 0.66 to 0.91). CONCLUSION: Participants at lower versus higher risk of future AN or CRC can be accurately identified based on their age, sex and particularly, prior F-Hb concentrations. Risk stratification should be considered based on this information.

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

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.

Prioritisation of colonoscopy services in colorectal cancer screening programmes to minimise impact of COVID-19 pandemic on predicted cancer burden: A comparative modelling study.

OBJECTIVES: Colorectal cancer (CRC) screening with a faecal immunochemical test (FIT) has been disrupted in many countries during the COVID-19 pandemic. Performing catch-up of missed screens while maintaining regular screening services requires additional colonoscopy capacity that may not be available. This study aimed to compare strategies that clear the screening backlog using limited colonoscopy resources. METHODS: A range of strategies were simulated using four country-specific CRC natural-history models: Adenoma and Serrated pathway to Colorectal CAncer (ASCCA) and MIcrosimulation SCreening ANalysis for CRC (MISCAN-Colon) (both in the Netherlands), Policy1-Bowel (Australia) and OncoSim (Canada). Strategies assumed a 3-month screening disruption with varying recovery period lengths (6, 12, and 24 months) and varying FIT thresholds for diagnostic colonoscopy. Increasing the FIT threshold reduces the number of referrals to diagnostic colonoscopy. Outcomes for each strategy were colonoscopy demand and excess CRC-related deaths due to the disruption. RESULTS: Performing catch-up using the regular FIT threshold in 6, 12 and 24 months could prevent most excess CRC-related deaths, but required 50%, 25% and 12.5% additional colonoscopy demand, respectively. Without exceeding usual colonoscopy demand, up to 60% of excess CRC-related deaths can be prevented by increasing the FIT threshold for 12 or 24 months. Large increases in FIT threshold could lead to additional deaths rather than preventing them. CONCLUSIONS: Clearing the screening backlog in 24 months could avert most excess CRC-related deaths due to a 3-month disruption but would require a small increase in colonoscopy demand. Increasing the FIT threshold slightly over 24 months could ease the pressure on colonoscopy resources.

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.

The national FIT-based colorectal cancer screening program in the Netherlands during the COVID-19 pandemic.

The COVID-19 pandemic has affected many healthcare services worldwide. Like many other nations, the Netherlands experienced large numbers of individuals affected by COVID-19 in 2020, leading to increased demands on hospitals and intensive care units. The Dutch Ministry of Health decided to suspend the Dutch biennial fecal immunochemical test (FIT) based colorectal cancer (CRC) screening program from March 16, 2020. FIT invitations were resumed on June 3. In this study, we describe the short-term effects of this suspension on a myriad of relevant screening outcomes. As a result of the suspension, a quarter of the individuals due for screening between March and November 2020 had not received their invitation for FIT screening by November 30, 2020. Furthermore, 57.8% of those who received a consecutive FIT between the restart and November 30, 2020, received it outside the upper limit of the standard screening interval (26 months). Median time between positive FIT and colonoscopy did not change as a result of the pandemic. Participation rates of FIT screening and follow-up colonoscopy in the months just before and during the suspension were significantly lower than expected, but returned to normal levels after the suspension. Based on the anticipated 2020 cohort size, we estimate that the number of individuals with advanced neoplasia currently detected up until November 2020 was 31.2% lower compared to what would have been expected without a pandemic. Future studies should monitor the impact on long-term screening outcomes as a result of the pandemic.

Effects of cancer screening restart strategies after COVID-19 disruption.

BACKGROUND: Many breast, cervical, and colorectal cancer screening programmes were disrupted due to the COVID-19 pandemic. This study aimed to estimate the effects of five restart strategies after the disruption on required screening capacity and cancer burden. METHODS: Microsimulation models simulated five restart strategies for breast, cervical, and colorectal cancer screening. The models estimated required screening capacity, cancer incidence, and cancer-specific mortality after a disruption of 6 months. The restart strategies varied in whether screens were caught up or not and, if so, immediately or delayed, and whether the upper age limit was increased. RESULTS: The disruption in screening programmes without catch-up of missed screens led to an increase of 2.0, 0.3, and 2.5 cancer deaths per 100 000 individuals in 10 years in breast, cervical, and colorectal cancer, respectively. Immediately catching-up missed screens minimised the impact of the disruption but required a surge in screening capacity. Delaying screening, but still offering all screening rounds gave the best balance between required capacity, incidence, and mortality. CONCLUSIONS: Strategies with the smallest loss in health effects were also the most burdensome for the screening organisations. Which strategy is preferred depends on the organisation and available capacity in a country.