Cost-effectiveness analysis of a quantitative immunochemical test for colorectal cancer screening

Optimal timing of a colonoscopy screening schedule depends on adenoma detection, adenoma risk, adherence to screening and the screening objective: A microsimulation study

Colonoscopy-based screening provides protection against colorectal cancer (CRC), but the optimal starting age and time intervals of screening colonoscopies are unknown. We aimed to determine an optimal screening schedule for the US population and its dependencies on the objective of screening (life years gained or incidence, mortality, or cost reduction) and the setting in which screening is performed. We used our established open-source microsimulation model CMOST to calculate optimized colonoscopy schedules with one, two, three or four screening colonoscopies between 20 and 90 years of age. A single screening colonoscopy was most effective in reducing life years lost from CRC when performed at 55 years of age. Two, three and four screening colonoscopy schedules saved a maximum number of life years when performed between 49-64 years; 44-69 years; and 40-72 years; respectively. However, for maximum incidence and mortality reduction, screening colonoscopies needed to be scheduled 4-8 years later in life. The optimum was also influenced by adenoma detection efficiency with lower values for these parameters favoring a later starting age of screening. Low adherence to screening consistently favored a later start and an earlier end of screening. In a personalized approach, optimal screening would start earlier for high-risk patients and later for low-risk individuals. In conclusion, our microsimulation-based approach supports colonoscopy screening schedule between 45 and 75 years of age but the precise timing depends on the objective of screening, as well as assumptions regarding individual CRC risk, efficiency of adenoma detection during colonoscopy and adherence to screening.

Comprehensive Cost Implications of Commercially Available Noninvasive Colorectal Cancer Screening Modalities

BACKGROUND

There is an increasing usage of noninvasive screening modalities for colorectal cancer (CRC), primarily the fecal immunochemical test (FIT) and multi-target stool DNA test (Cologuard [CG]). The aim of this study was to determine the comprehensive, long-term cost implications of these noninvasive screening modalities.

STUDY DESIGN

Using a national insurer-based administrative dataset, patients screened for CRC from January 1, 2019 to December 31, 2019 were analyzed. A hierarchical logic system was used to determine the primary screening modality for each patient. The total annual costs in US dollars ($) were extrapolated using number of patients screened, costs per test, screening intervals, and costs incurred from false results. Patients within our tumor registry diagnosed with CRC were matched to their claims data, and cancer stage distribution was compared.

RESULTS

Of 119,334 members who underwent noninvasive screening, 38.1% underwent screening with FIT and 40.0% with CG. The combined annual cost for these 2 screening modalities was $13.7 million. By transitioning to FIT alone for all noninvasive screening, the total annual cost would decrease to $7.9 million, resulting in a savings of approximately $5.8 million per year. Additionally, by combining data from the network cancer registry and insurer-based claims dataset, we were able to match 533 individuals who underwent screening and were later diagnosed with CRC. The rate of early-stage (stage 0 to II) disease was found to be similar between those screened with FIT and CG (59.5% FIT vs 63.2% CG; p = 0.77).

CONCLUSIONS

The adoption of FIT as the primary noninvasive CRC screening method has the potential to generate significant cost savings, and therefore, carries significant value implications for a large population health system.

A Systematic Review of Cost-Effectiveness Analyses of Colorectal Cancer Screening in Europe: Have Studies Included Optimal Screening Intensities?

OBJECTIVE

To assess the range of strategies analysed in European cost-effectiveness analyses (CEAs) of colorectal cancer (CRC) screening with respect to the screening intervals, age ranges and test cut-offs used to define positivity, to examine how this might influence what strategies are found to be optimal, and compare them with the current screening policies with a focus on the screening interval.

METHODS

We searched PubMed, Web of Science and Scopus for peer-reviewed, model-based CEAs of CRC screening. We included studies on average-risk European populations using the guaiac faecal occult blood test (gFOBT) or faecal immunochemical test (FIT). We adapted Drummond's ten-point checklist to appraise study quality.

RESULTS

We included 39 studies that met the inclusion criteria. Biennial screening was the most frequently used interval which was analysed in 37 studies. Annual screening was assessed in 13 studies, all of which found it optimally cost-effective. Despite this, 25 of 26 European stool-based programmes use biennial screening. Many CEAs did not vary the age range, but the 14 that did generally found broader ranges optimal. Only 11 studies considered alternative FIT cut-offs, 9 of which found lower cut-offs superior. Conflicts between current policy and CEA evidence are less clear regarding age ranges and cut-offs.

CONCLUSIONS

The existing CEA evidence indicates that the widely adopted biennial frequency of stool-based testing in Europe is suboptimal. It is likely that many more lives could be saved throughout Europe if programmes could be offered with more intensive annual screening.

COLORECTAL CANCER: ASSOCIATION BETWEEN SOCIODEMOGRAPHIC VARIABLES AND THE ADHERENCE TO CANCER SCREENING

BACKGROUND

Colorectal cancer (CRC) is a worldwide health problem whose control depends on public policy establishment and effective prevention and screening programs. In Brazil, there are few studies related to adherence to screening methods.

AIMS

The aim of this study was to evaluate the association between demographic and socioeconomic to adherence to CRC screening with fecal immunochemical test (FIT) among average-risk individuals for CRC.

METHODS

In this prospective cross-sectional study, conducted between March 2015 and April 2016, 1,254 asymptomatic individuals aged 50-75 years, participating in a hospital screening campaign in Brazil, were invited to participate in the study.

RESULTS

The adherence rate to FIT was 55.6% (697/1,254). In the multivariable logistic regression analysis, patients aged 60-75 years (odds ratio (OR)=1.30; 95% confidence interval (CI): 1.02-1.66; p=0.03), religious belief (OR=2.04; 95% CI: 1.34-3.11; p<0.01), previous fecal occult blood test (OR=2.07; 95% CI: 1.55-2.76; p<0.01), and full/part-time working status (OR=0.66; 95% CI: 0.49-0.89; p<0.01) were independently associated with adherence to CRC screening.

CONCLUSION

The results of the present study highlight the importance of considering the labor aspects when implementing screening programs, suggesting that campaigns conducted in the workplace and repeated over the years may be more effective.

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.

Colorectal cancer incidence, mortality, tumour characteristics, and treatment before and after introduction of the faecal immunochemical testing-based screening programme in the Netherlands: a population-based study

BACKGROUND

In 2014, a population-based colorectal cancer (CRC) screening programme was stepwise implemented in the Netherlands comprising faecal immunochemical testing once every 2 years, with a cutoff value for positivity of 47 μg haemoglobin per g faeces. We aimed to assess CRC incidence, mortality, tumour characteristics, and treatment before and after introduction of this screening programme.

METHODS

We did a retrospective, observational, population-based study in the Netherlands and gathered CRC incidence data from the Netherlands Cancer Registry from Jan 1, 2010, to Dec 31, 2019, in people aged 55 years or older. Patients with a CRC diagnosis between Jan 1, 2014, and Dec 31, 2018, in the Netherlands Cancer Registry were linked with the nationwide registry of histopathology and cytopathology (PALGA) to identify mode of detection (ie, screening-detected vs clinically detected). We calculated age-standardised CRC incidence rates and used data from Statistics Netherlands to calculate CRC-related mortality in 2010-19. We compared localisation, stage distribution, and treatment of screening-detected CRCs with clinically detected CRCs diagnosed in 2014-18 in patients aged 55-75 years.

FINDINGS

Between Jan 1, 2010, and Dec 31, 2019, 125 215 CRCs were diagnosed in individuals aged 55 years or older and were included in the analyses for CRC incidence. Before the introduction of the screening programme, the age-standardised CRC incidence rate was 214·3 per 100 000 population in 2013 in people aged 55 years or older. After the introduction of the screening programme, this rate initially increased to 259·2 per 100 000 population in 2015, and subsequently decreased to 181·5 per 100 000 population in 2019. Age-standardised incidence rates for advanced CRCs (stage III and IV) were 117·0 per 100 000 population in 2013 and increased to 122·8 per 100 000 population in 2015; this rate then decreased to 94·7 per 100 000 population in 2018. Age-standardised CRC mortality decreased from 87·5 deaths per 100 000 population in 2010 to 64·8 per 100 000 population in 2019. Compared with clinically detected CRCs, screening-detected CRCs were more likely to be located in the left side of the colon (48·6% vs 35·2%) and to be detected at an early stage (I or II; 66·7% vs 46·2%). Screening-detected CRCs were more likely to be treated by local excision compared with clinically detected CRCs, and this finding persisted when stage I CRCs were analysed separately.

INTERPRETATION

After introduction of this national screening programme, a decrease in overall and advanced-stage CRC incidence was observed. In view of this observation, together with the observed shift to detection at earlier stages and more screening-detected CRCs being treated by local excision, we might cautiously conclude that, in the long-term, faecal immunochemical testing-based screening could ultimately lead to a decrease in CRC-related morbidity and mortality.

FUNDING

None.

Analysis of Post-Colonoscopy Colorectal Cancer and Its Subtypes in a Screening Programme

Using the algorithm of the World Endoscopy Organisation (WEO), we have studied retrospectively all colorectal cancers, both detected and non-detected by the Basque Country screening programme from 2009 to 2017. In the screening programme 61,335 colonoscopies were performed following a positive Faecal Immunochemical test (FIT) (≥20 µg Hb/g faeces) and the 128 cases of post-colonoscopy colorectal cancer (PCCRC) detected were analysed. Among them, 50 interval type PCCRCs were diagnosed (before the recommended surveillance), 0.8 cases per 1000 colonoscopies performed, and 78 non-interval type PCCRCs (in the surveillance carried out at the recommended time or delayed), 1.3 per 1000 colonoscopies. Among the non-interval type PCCRCs, 61 cases were detected in the surveillance carried out at the recommended time (type A) and 17 when the surveillance was delayed (type B), 1 case per 1000 colonoscopies performed and 0.28 cases per 1000 colonoscopies performed, respectively. Interval type PCCRC is less frequent than non-interval type PCCRC. In interval type PCCRCs, CRCs detected in advanced stages (stages III-IV) were significantly more frequent than those detected in early stages, compared to those of non-interval type PCCRCs (OR = 3.057; 95% CI, 1.410-6.625; p < 0.005). Non-interval type B PCCRCs are less frequent than non-interval type A PCCRCs, but the frequency of advanced stages is higher in interval type B PCCRCs.

Population-based organized screening by faecal immunochemical testing and colorectal cancer mortality: a natural experiment

BACKGROUND

Population-based organized screening programmes for colorectal cancer (CRC) are underway worldwide, with many based on the faecal immunochemical test (FIT). No clinical trials assessing FIT compared with no screening are planned, and few studies have assessed the population impact of such programmes.

METHODS

Before 2010, 11 out of 50 Spanish provinces initiated population-based organized screening programmes with FIT for an average-risk population aged 50-69 years. We used a quasi-experimental design across Spanish provinces between 1999 and 2016 to evaluate their impact on population age-standardized mortality and incidence rates due to CRC. Difference-in-differences and synthetic control analyses were performed to test for validation of statistical assumptions and to assess the dynamics of screening-associated changes in outcomes over time.

RESULTS

No differences in outcome trends between exposed (n = 11) and control (n = 36) provinces were observed for up to 7 years preceding the implementation of screening. Relative to controls, exposed provinces experienced a mean increase in age-standardized incidence of 10.08% [95% confidence interval (CI) (5.09, 15.07)] 2 years after implementation, followed by a reduction in age-standardized mortality rates due to CRC of 8.82% [95% CI (3.77, 13.86)] after 7 years. Results were similar for both women and men. No associated changes were observed in adjacent age bands not targeted by screening, nor for 10 other major causes of death in the exposed provinces.

CONCLUSIONS

FIT-based organized screening in Spain was associated with reductions in population colorectal cancer mortality. Further research is warranted in order to assess the replicability and external validity of our findings, and on gender-specific use of FIT in organized screening.

Colorectal cancer incidence and mortality after negative fecal immunochemical tests by age 70: A prospective observational study

Limited endoscopy capacity usually represents the main barrier to the extension of screening to subjects older than 70, given the high positivity rate in this age group. We assessed CRC incidence and mortality by number of previous negative fecal immunochemical tests (FIT) among subjects turning 70. We selected persons aged 70 years who had received their last screening invitation when they were 68 or 69 years old within the population-based screening program in the Veneto region of Italy. Subjects with a positive FIT were excluded. We calculated 10-year cumulative CRC incidence and mortality in cohorts of subjects having performed zero, one, two or three negative FITs over the last three screening rounds before turning 70. Out of 117 858 subjects included in the study (46.4% men), 33.7% had never participated in screening (zero negative FITs), 23.3% had had one-negative FIT, 20.1% two-negative FITs and 22.9% three negative FITs. The 10-year cumulative CRC incidence was 29.7 per 1000 subjects with zero FITs, and respectively, 14.5, 11.7 and 9.6 per 1000 subjects with one, two and three negative FITs. The corresponding figures for 10-year cumulative mortality were 9.3, 3.5, 2.2 and 2.1 per 1000 in the four study cohorts. Figures were roughly double for men than for women for all the study cohorts. In order to use more efficiently limited endoscopy resources, and to minimize the potential harms related to false positive results in the elderly, screening among people aged 70 to 74 might be restricted to those with zero previous negative FITs.

Colorectal cancer screening programme: is the French faecal immunological test (FIT) threshold optimal?

BACKGROUND

In France, the colorectal cancer organised screening programme uses the faecal immunological test. A positive test ⩾30 μg Hb/g of stool leads to a colonoscopy for identification of potential colorectal lesions. Cut-off values vary from 20 to 47 μg Hb/g of stool in Western countries. We herein question this threshold's relevance in a French population and perform a retrospective observational study using the Parisian database between 1 April 2015 and 31 December 2018.

METHODS

Rates of participation, numbers of positive faecal immunological test (FIT), detection rates and positive predictive values for advanced adenomas and/or colorectal cancer were determined. Mean positivity values for colorectal lesions were calculated.

RESULTS

In our population, there were 4.1% positive tests and 67.6% colonoscopy results available with final reports. Positive predictive value for advanced adenomas and colorectal cancer were 30% [95% confidence interval (CI) 29.8-30.3] and 7.4% (95% CI 7.35-7.52), respectively. The mean positivity value for all positive tests in our population was 101.7 µg Hb/g of stool (95% CI 85-118.3). There were 1136 normal colonoscopies (21.4%) with a mean positivity value of 88.6 μg Hb/g of stool. Following a negative test in a first screening campaign, 40.8% of patients in our population performed a second test with a positivity rate of 1.3% and with the encounter of 81 colorectal cancers. The risk of having a positive test during the second screening campaign and finding advanced colorectal lesions significantly increased (all p < 0.001) when comparing negative FIT results ranging between 15 and 29 μg Hb/g of stool to 0 and 14 μg Hb/g of stool from the previous campaign.

CONCLUSION

Using the current positivity threshold, some patients were considered negative with a delay in colorectal cancer diagnosis, suggesting the threshold could be lowered. Also, the mean positivity value for normal colonoscopies was high, raising the question of upper gastrointestinal bleeding.

Cost-effectiveness analysis of alternative colorectal cancer screening strategies in high-risk individuals

BACKGROUND AND AIMS

Current guidelines recommend colonoscopy every 3-5 years for colorectal cancer (CRC) screening of individuals with a familial history of CRC. The objective of this study was to compare the cost effectiveness of screening alternatives in this population.

METHODS

Eight screening strategies were compared with no screening: fecal immunochemical test (FIT), Stool DNA and blood-based screening every 2 years, colonoscopy, computed tomography colonography, colon capsules, and sigmoidoscopy every 5 years, and colonoscopy at 45 years followed, if negative, by FIT every 2 years. Screening test and procedures performance were obtained from the literature. A microsimulation model reproducing the natural history of CRC was used to estimate the cost (€2018) and effectiveness [quality-adjusted life-years (QALYs)] of each strategy. A lifetime horizon was used. Costs and effectiveness were discounted at 3.5% annually.

RESULTS

Compared with no screening, colonoscopy and sigmoidoscopy at a 30% uptake were the most effective strategy (46.3 and 43.9 QALY/1000). FIT at a 30 µg/g threshold with 30% uptake was only half as effective (25.7 QALY). Colonoscopy was associated with a cost of €484,000 per 1000 individuals whereas sigmoidoscopy and FIT were associated with much lower costs (€123,610 and €66,860). Incremental cost-effectiveness rate for FIT and sigmoidoscopy were €2600/QALY (versus no screening) and €3100/QALY (versus FIT), respectively, whereas it was €150,000/QALY for colonoscopy (versus sigmoidoscopy). With a lower threshold (10 µg/g) and a higher uptake of 45%, FIT was more effective and less costly than colonoscopy at a 30% uptake and was associated with an incremental cost-effectiveness ratio (ICER) of €4240/QALY versus no screening.

CONCLUSION

At 30% uptake, current screening is the most effective screening strategy for high-risk individuals but is associated with a high ICER. Sigmoidoscopy and FIT at lower thresholds (10 µg/g) and a higher uptake should be given consideration as cost-effective alternatives.

PLAIN LANGUAGE SUMMARY

Cost-effectiveness analysis of colorectal cancer screening strategies in high-risk individuals Fecal occult blood testing with an immunochemical test (FIT) is generally considered as the most cost-effective alternative in colorectal cancer screening programs for average risk individuals without family history.Current screening guidelines for high-risk individuals with familial history recommend colonoscopy every 3-5 years.Colonoscopy every 3-5 years for individuals with familial history is the most effective strategy but is associated with a high incremental cost-effectiveness ratio.Compared with colonoscopy, if screening based on FIT is associated with a higher participation rate, it can achieve a similar effectiveness at a lower cost.

Combining the Fecal Immunochemical Test with a Logistic Regression Model for Screening Colorectal Neoplasia

Background: The fecal immunochemical test (FIT) is a widely used strategy for colorectal cancer (CRC) screening with moderate sensitivity. To further increase the sensitivity of FIT in identifying colorectal neoplasia, in this study, we established a classifier model by combining FIT result and other demographic and clinical features.

Methods: A total of 4,477 participants were examined with FIT and those who tested positive (over 100 ng/ml) were followed up by a colonoscopy examination. Demographic and clinical information of participants including four domains (basic information, clinical history, diet habits and life styles) that consist of 15 features were retrieved from questionnaire surveys. A mean decrease accuracy (MDA) score was used to select features that are mostly related to CRC. Five different algorithms including logistic regression (LR), classification and regression tree (CART), support vector machine (SVM), artificial neural network (ANN) and random forest (RF) were used to generate a classifier model, through a 10X cross validation process. Area under curve (AUC) and normalized mean squared error (NMSE) were used in the evaluation of the performance of the model.

Results: The top six features that are mostly related to CRC include age, gender, history of intestinal adenoma or polyposis, smoking history, gastrointestinal discomfort symptom and fruit eating habit were selected. LR algorithm was used in the generation of the model. An AUC score of 0.92 and an NMSE score of 0.076 were obtained by the final classifier model in separating normal individuals from participants with colorectal neoplasia.

Conclusion: Our results provide a new “Funnel” strategy in colorectal neoplasia screening via adding a classifier model filtering step between FIT and colonoscopy examination. This strategy minimizes the need of colonoscopy examination while increases the sensitivity of FIT-based CRC screening.

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.

Cost-effectiveness analysis of alternative colon cancer screening strategies in the context of the French national screening program

BACKGROUND

A nationwide colorectal cancer (CRC) screening program was set up in France from 2009 for average-risk, asymptomatic people aged 50-74 years based on an immunochemical fecal occult blood test [faecal immunochemical test (FIT)] every 2 years, followed by colonoscopy if positive. The European standard recommends a participation rate of 45% for the program to be cost-effective, yet the latest published rate in France was 34%. The objective of this study was to compare the cost effectiveness of screening alternatives taking real-world participation rates into account.

METHODS

Eight screening strategies were compared, based either on a screening test (Guaiac or FIT testing, blood-based, stool DNA, computed tomography colonography, colon capsules, and sigmoidoscopy) followed by full colonoscopy if positive or direct colonoscopy. A microsimulation model was used to estimate the cost effectiveness associated with each strategy.

RESULTS

Compared with no screening, FIT was associated with a 14.0 quality-adjusted life year (QALY) increase of €50,520 per 1000 individuals, giving an incremental cost-effectiveness ratio (ICER) of €3600/QALY. Only stool DNA and blood-based testing were associated with a QALY increase compared with FIT, with stool DNA weakly dominated by blood-based testing, and the latter associated with an ICER of €154,600/QALY compared with FIT. All other strategies were dominated by FIT.

CONCLUSION

FIT every 2 years appears to be the most cost-effective CRC screening strategy when taking into account a real-world participation rate of 34%.

Non-Invasive Colorectal Cancer Screening: An Overview

Background

Colorectal cancer (CRC) follows a protracted stepwise progression, from benign adenomas to malignant adenocarcinomas. If detected early, 90% of deaths are preventable. However, CRC is asymptomatic in its early-stage and arises sporadically within the population. Therefore, CRC screening is a public health priority.

Summary

Faecal immunochemical test (FIT) is gradually replacing guaiac faecal occult blood test and is now the most commonly used screening tool for CRC screening program globally. However, FIT is still limited by the haemoglobin degradation and the intermittent bleeding patterns, so that one in four CRC cases are still diagnosed in a late stage, leading to poor prognosis. A multi-target stool DNA test (Cologuard, a combination of NDRG4 and BMP3 DNA methylation, KRAS mutations, and haemoglobin) and a plasma SEPT9 DNA methylation test (Epi proColon) are non-invasive tools also approved by the US FDA, but those screening approaches are not cost-effective, and the detection accuracies remain unsatisfactory. In addition to the approved tests, faecal-/blood-based microRNA and CRC-related gut microbiome screening markers are under development, with work ongoing to find the best combination of molecular biomarkers which maximise the screening sensitivity and specificity.

Key Message

Maximising the detection accuracy with a cost-effective approach for non-invasive CRC screening is urgently needed to further reduce the incidence of CRC and associated mortality rates.

[Estimated impact of the current colorectal screening program in France]

BACKGROUND

Colorectal cancer is the third most common cancer and the second most deadly in France. A Cochrane meta-analysis has confirmed the benefits of colorectal cancer screening. A nationwide colorectal screening program was set up in France in 2009 for medium-risk, asymptomatic people aged 50 to 74 years. It has been based, since 2015, on the Fecal Immunochemical Test. The participation rate for 2016-2017 was 34%, which is lower than the European objectives. The objective of this study was to evaluate the impact of the program at the current participation rate and at rates of 45% and 65%.

METHODS

The epidemiological impact of the program was estimated from the results of an individual simulation model adapted from the Microsimulation Screening Analysis Colon model, calibrated and transposed to the French context. An initial analysis was conducted to estimate the individual impact of screening and a second for the entire eligible population, at various participation rates.

RESULTS

The test is associated with a lifetime reduction in the risk of colorectal cancer of 24% for men and 21% for women, and a reduction in the risk of death from colorectal cancer of 51% and 43% respectively. At the current level of participation, the program reduces incidence by 5% and mortality by 14% compared to no organized screening. The impact would be reduced by an additional 3% and 8% for participation rates of 45% and 65% respectively. Similarly, mortality would decrease by an additional 8% and 22%.

CONCLUSION

These results confirm that in a population at medium risk for colorectal cancer, the organised programme is an effective strategy for reducing its incidence. They also confirm that the achievement of European objectives remains a key issue for improving the effectiveness of organized screening. An evolution of immunological test delivery modalities could help to achieve these participation objectives.

Effects of screening and universal healthcare on long-term colorectal cancer mortality

BACKGROUND

To evaluate the time trends of colorectal cancer (CRC) affected by a Nationwide Colorectal Cancer Screening (NCCS) programme with biennial faecal immunochemical testing (FIT) and Nationwide Healthcare Insurance (NHI).

METHODS

Data from the national registries on cancer and death in Taiwan were separated into years 1984-1993, 1994-2003 and 2004-2013 based on the implementations of NHI (starting 1995) and NCCS (starting 2004). The adult population was divided into three age groups (young, 30-49; middle-aged, 50-69; and old, 70-84 years); only the middle-aged were eligible for NCCS. Crude and adjusted effects of NCCS and NHI were quantified by percentage change and 95% confidence interval (CI) with respect to CRC mortality, according to the attributions from incidence and survival.

RESULTS

Within 335 million person-years of follow-up, 204 362 incident CRCs and 80 771 CRC-related deaths were identified. Increasing mortality trends were noted for 1994-2003 (post-NHI) vs 1984-1993 due to remarkable increasing incidence trends that could not be offset by improved survival as a result of NHI. During 2004-13 (post-NCCS), mortality continued to increase by 15% (95% CI: 10-21%) in young adults (30-49 years) and 8% (95% CI: 6-11%) in older adults (70-84 years), whereas middle-aged adults (50-69 years) had a reduction of 7% (95% CI: 5-9%) due to a remarkable stage shift and subsequent improvement in survival. In the middle-aged adults, increased incidence was less but survival improvement was more compared with other age groups.

CONCLUSIONS

Whereas universal healthcare insurance led to improvement in CRC survival, FIT-based screening has made an even greater contribution to reducing CRC mortality.

A Correlation Study of the Colorectal Cancer Statistics and Economic Indicators in Selected Balkan Countries

Colorectal cancer (CRC) is one of the most commonly diagnosed malignant neoplasms. The aim of the study was to evaluate and correlate most important epidemiological and economic indicators of CRC in 11 selected Balkan countries. The number of new CRC cases was 56,960, and the highest 5-year CRC prevalence was in Slovenia, Croatia, and Greece. Age-standardized CRC incidence rates were highest in Slovenia, Serbia, and Croatia, and age-standardized mortality rates were highest in Croatia, Serbia, and Bulgaria. Current Health Expenditure as % of Gross Domestic Product was the highest in Bosnia and Herzegovina and Serbia. The GDP per capita levels have shown positive correlation with the CRC incidence rate and prevalence. Absolute numbers of new and death-related CRC cases and 5-year prevalence in absolute numbers have shown strong positive correlation with GDP in million current US$. It has been shown that various economic indicators can be linked to the rate of incidence and prevalence of the CRC patients in the selected Balkan countries. Therefore, economic factors can influence the epidemiology of CRC, and heavy CRC burden in the Balkan region may be one of the indexes of the economic development.

Diagnostic Accuracy of Stool Tests for Colorectal Cancer Surveillance in Hodgkin Lymphoma Survivors

BACKGROUND

Hodgkin lymphoma (HL) survivors have an increased colorectal cancer (CRC) risk. Diagnostic accuracy of quantitative fecal immunochemical testing (FIT, OC Sensor) and/or a multi-target stool DNA test (mt-sDNA, Cologuard^®) for advanced neoplasia (AN) was evaluated.

METHODS

101 HL survivors underwent a surveillance colonoscopy and were asked to perform two stool tests (FIT and mt-sDNA). Advanced adenoma (AA), advanced serrated lesion (ASL), and AN (AA, ASL, CRC) were evaluated. Sensitivity, specificity, and area under the curve (AUC) for AN were calculated for different FIT cut-offs and mt-sDNA with colonoscopy as reference.

RESULTS

FIT and mt-sDNA were analyzed in 73 (72%) and 82 (81%) participants, respectively. AN was detected in 19 (26%) and 22 (27%), respectively. AN sensitivities for FIT cut-off of 10 ug Hb/g feces (FIT10) and mt-sDNA were 37% (95% confidence interval (CI): 16-62) and 68% (95% CI: 45-86), with corresponding specificities of 91% (95% CI: 80-97) and 70% (95% CI: 57-86), respectively. AUC for FIT was 0.68 (95% CI: 0.54-0.82) and for mt-sDNA 0.76 (95% CI: 0.63-0.89).

CONCLUSIONS

In HL survivors, mt-sDNA showed highest sensitivity but with relatively low specificity for AN. Cost-effectiveness analyses is necessary to determine the optimal surveillance strategy.

Towards risk-stratified colorectal cancer screening. Adding risk factors to the fecal immunochemical test: Evidence, evolution and expectations

With increasing incidence and mortality, colorectal cancer (CRC) is a growing health problem worldwide. An effective way to address CRC is by screening for fecal (occult) blood by the fecal immunochemical test (FIT). However, there is room for improvement since precursor lesions and CRC bleed intermittent and can therefore be missed by the FIT (false negatives) or, the detected blood did not result from precursor lesions or CRC (false positives). This review provides the latest evidence on risk prediction models using FIT combined with additional risk factors before colonoscopy, which risk factors to include and if these models will better discriminate between normal findings and CRC compared to the FIT-only. Many prediction models are known for CRC, but compared to the FIT, these are less effective in detecting CRC. The literature search resulted in 645 titles where 11 papers matched the inclusion criteria and were analyzed. Comparing the FIT-only with the risk prediction models for detecting CRC resulted in a significantly increased discrimination for the models. In addition, 2 different risk-stratification categories before colonoscopy were distinguished, namely the 1-model approach which combined risk factors with FIT results in a prediction model while the 2 step approach used risk factors apart from the FIT. Finally, combining FIT with CRC risk factors by means of a model before colonoscopy seems effective regarding discriminative power, however, more research is needed for validation combined with transparent and standardized reporting to improve quality assessment, for which suggestions are reported in this study.

Cost-Effectiveness of Colorectal Cancer Screening Strategies-A Systematic Review

BACKGROUND & AIMS

Widespread screening for colorectal cancer (CRC) has reduced its incidence and mortality. Previous studies investigated the economic effects of CRC screening. We performed a systematic review to provide up-to-date evidence of the cost effectiveness of CRC screening strategies by answering 3 research questions.

METHODS

We searched PubMed, National Institute for Health Research Economic Evaluation Database, Social Sciences Citation Index (via the Web of Science), EconLit (American Economic Association) and 3 supplemental databases for original articles published in English from January 2010 through December 2017. All monetary values were converted to US dollars (year 2016). For all research questions, we extracted, or calculated (if necessary), per-person costs and life years (LYs) and/or quality-adjusted LYs, as well as the incremental costs per LY gained or quality-adjusted LY gained compared with the baseline strategy. A cost-saving strategy was defined as one that was less costly and equally or more effective than the baseline strategy. The net monetary benefit approach was used to answer research question 2.

RESULTS

Our review comprised 33 studies (17 from Europe, 11 from North America, 4 from Asia, and 1 from Australia). Annual and biennial guaiac-based fecal occult blood tests, annual and biennial fecal immunochemical tests, colonoscopy every 10 years, and flexible sigmoidoscopy every 5 years were cost effective (even cost saving in most US models) compared to no screening. In addition, colonoscopy every 10 years was less costly and/or more effective than other common strategies in the United States. Newer strategies such as computed tomographic colonography, every 5 or 10 years, was cost effective compared with no screening.

CONCLUSIONS

In an updated review, we found that common CRC screening strategies and computed tomographic colonography continued to be cost effective compared to no screening. There were discrepancies among studies from different regions, which could be associated with the model types or model assumptions.

Impact of a higher fecal immunochemistry test cut-off on pathology detected in subsequent rounds of a colorectal screening program

BACKGROUND AND AIMS

Fecal immunochemical test (FIT)-based colorectal cancer (CRC) screening is superior to the traditional binary fecal occult blood test. Its quantitative nature allows the investigator to choose a positivity threshold to match cost and endoscope capacity. The optimal threshold is still debated. BowelScreen, the Irish national colorectal cancer screening program, has a cut-off of 45 μg Hb/g feces, and in this study we investigated the impact of this threshold on pathology detected in round 2 in individuals who had a negative result for round 1 FIT (FIT¹).

METHODS

All individuals with a negative FIT¹ result who completed a round 2 FIT (FIT²) 2 years later were included. Pathology outcomes for individuals who had positive FIT² results were correlated with FIT¹ levels.

RESULTS

A total of 37,877 individuals had negative FIT¹ results and completed FIT². One thousand two hundred thirty (3.2%) had positive FIT² results (702 men [57%], median age 69, age range 60-70 years). Quantitative analysis showed that at an FIT¹ level <5 μg Hb/g feces, 2.3% had positive FIT² results. At a higher cut-off of 40.1 to 45 μg Hb/g feces, 15.6% of individuals had positive FIT² results. One thousand two (81.5%) underwent colonoscopy, with clinical outcomes in all cases. Three hundred fifty-one (35%) had normal colonoscopy results. The proportion of individuals with normal colonoscopy results decreased as FIT¹ levels rose. Conversely, advanced pathology (CRC + high-risk adenomas) rates rose from 7% to 50% when FIT¹ was <5 compared with 40.1 to 45 μg Hb/g feces, respectively. There were 51 screen-detected cancers in round 2 among individuals with negative FIT¹ results (22 stage I, 12 stage II, 14 stage III, 3 stage IV). All 3 stage IV individuals had FIT¹ results <20 μg Hb/g feces.

CONCLUSIONS

Varying rates of pathology are observed in round 2 of a screening program based on the quantitative level of a negative round 1 FIT result when the positivity threshold is relatively high. A CRC rate of 5.1% within this group appears acceptable. Although patients with incurable cancer were observed, the positivity threshold to capture these cases within round 1 would have been so sensitive that it would create an unsustainable endoscopy referral burden.

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.

The fecal immunochemical test (fit): Selected aspects regarding its effectiveness for colorectal cancer screening in Quebec City

BACKGROUND AND AIMS

FIT's value has been ascertained across Canada and worldwide, but still needs to be assessed within the province of Quebec. There also remains a gap between formal indications for FIT, and its actual use in clinical practice. This research aims to evaluate some aspects of FIT's effectiveness in our setting, and its application by prescribers.

METHODS

We retrospectively identified and reviewed all the colonoscopies conducted for a positive FIT in 2014 at 2 hospitals located in Quebec City.

RESULTS

Five hundred and fifty-nine (559) colonoscopies were reviewed. We obtained PPVs of 6.8% and 46.9% for the detection of CRC and AA, respectively. The PPV for the detection of SCL was higher in men compared to women (OR 1.56, 95%CI 1.11-2.20) and among justified FITs compared to unwarranted ones (OR 1.88, 95%CI 1.34-2.63). The PPV for CRC detection was 25.0% in the presence of unexplained iron deficiency anemia and 6.5% when anemia was absent (p = 0.0058). In 49.9% of cases, the prescription of a FIT was inappropriate.

CONCLUSION

The FIT holds a better PPV for detecting SCL among men and when it is indicated. Anemia is associated with a higher CRC detection rate. Half of the FITs were not initially indicated.

Proton pump inhibitors reduce the accuracy of faecal immunochemical test for detecting advanced colorectal neoplasia in symptomatic patients

Background

The faecal immunochemical test (FIT) is used in colorectal cancer (CRC) screening and for the detection of advanced colorectal neoplasia (AN) in symptomatic patients, but its accuracy could be improved. Our objective was to assess the impact of proton pump inhibitors (PPI) on the accuracy of the FIT in the detection of AN, namely advanced colorectal adenoma and CRC.

Methods and findings

We performed a prospective study of 1002 individuals referred for a diagnostic colonoscopy at Bellvitge University Hospital from September 2011 through to October 2012. An exhaustive interview was performed by a gastroenterologist, prescription drug dispensing database was reviewed and the patient was given a FIT prior to colonoscopy. The positivity threshold of FIT used was ≥ 20 μg Hb/g feces and the main outcome was AN. AN was detected in 13.2% (133) of patients. The accuracy of FIT for detecting AN in the PPI users and non-PPI users were: sensitivity 43.0% vs 65.6%, P = 0.009; specificity 86.9% vs 92.3%, P = 0.010; and, predictive positive value 34.4% vs 55.5%, P = 0.007, respectively. In multivariate analysis, adjusting for potential confounders, PPIs were associated with false positives in AN detection by FIT (OR 1.63 CI 95% 1.02–2.59, P < 0.037). The ROC curve for the FIT in the detection of AN in the PPI users and non-PPI users was 0.68 (CI 95% 0.61–0.76) and 0.85 (CI 95% 0.79–0.90).

Conclusions

PPI therapy reduces the accuracy of FIT for detecting AN in symptomatic patients.

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.

Cost-effectiveness of High-performance Biomarker Tests vs Fecal Immunochemical Test for Noninvasive Colorectal Cancer Screening

BACKGROUND & AIMS

Biomarker assays could increase the accuracy of noninvasive detection of colorectal cancer (CRC); fecal immunochemical tests (FITs) are estimated to miss 27%-47% of CRCs and 70%-80% of advanced adenomas per round of screening. We investigated the conditions under which biomarker screens would be cost-effective compared with FIT screens of average-risk individuals.

METHODS

We used the MISCAN-Colon microsimulation model to estimate the effects of various CRC screening test characteristics on life-years gained (LYG) and; age-specific all-cause mortality was based on the 2010 Dutch life tables. Simulated CRC incidence rate and CRC stage distribution were calibrated to observed data in The Netherlands from 1999 through 2003 (before opportunities for screening). Survival rates after diagnosis of CRC at an age younger than 75 years were based on CRC relative survival data from 1985 through 2004; survival for individuals diagnosed at an age of 75 years or older was adjusted to fit the observed age-increasing mortality/incidence ratio. We modeled FIT along with hypothetical biomarker tests with different test performance levels. For each biomarker test we calculated the maximum unit cost for the test to be cost-effective compared with FIT, assuming a willingness-to-pay threshold of €50,000 ($56,000) per LYG.

RESULTS

Biennial FIT screening of subjects 55-75 years old provided 84.9 LYG at a cost of €122,000 ($137,000) per 1000 participants. Considering a unit cost of €7 ($8) for FIT (including kit and analysis only, excluding organizational costs), a biomarker test that detects CRC with higher levels of specificity and sensitivity (100%) and advanced adenomas at a proportionally higher level of sensitivity (53%) should never exceed a cost of €51 ($57). The threshold cost could increase to more than €200 ($224) for high-performing biomarker tests in cases of limited colonoscopy capacity or higher uptake of this test.

CONCLUSIONS

By using the MISCAN-Colon microsimulation model to estimate effects of CRC screening tests, we found that for a biomarker test with increased overall performance to be cost-effective, it should not exceed 7-fold the unit cost of FIT. This maximum would increase substantially if colonoscopy becomes more expensive or scarce, or if the new test has higher screening uptake. These values could be used to estimate the added value of new biomarkers compared with current FIT screening.

Demand for Colonoscopy in Colorectal Cancer Screening Using a Quantitative Fecal Immunochemical Test and Age/Sex-Specific Thresholds for Test Positivity

Background: Despite age and sex differences in fecal hemoglobin (f-Hb) concentrations, most fecal immunochemical test (FIT) screening programs use population-average cut-points for test positivity. The impact of age/sex-specific threshold on FIT accuracy and colonoscopy demand for colorectal cancer screening are unknown.Methods: Using data from 723,113 participants enrolled in a Taiwanese population-based colorectal cancer screening with single FIT between 2004 and 2009, sensitivity and specificity were estimated for various f-Hb thresholds for test positivity. This included estimates based on a "universal" threshold, receiver-operating-characteristic curve-derived threshold, targeted sensitivity, targeted false-positive rate, and a colonoscopy-capacity-adjusted method integrating colonoscopy workload with and without age/sex adjustments.Results: Optimal age/sex-specific thresholds were found to be equal to or lower than the universal 20 μg Hb/g threshold. For older males, a higher threshold (24 μg Hb/g) was identified using a 5% false-positive rate. Importantly, a nonlinear relationship was observed between sensitivity and colonoscopy workload with workload rising disproportionately to sensitivity at 16 μg Hb/g. At this "colonoscopy-capacity-adjusted" threshold, the test positivity (colonoscopy workload) was 4.67% and sensitivity was 79.5%, compared with a lower 4.0% workload and a lower 78.7% sensitivity using 20 μg Hb/g. When constrained on capacity, age/sex-adjusted estimates were generally lower. However, optimizing age/-sex-adjusted thresholds increased colonoscopy demand across models by 17% or greater compared with a universal threshold.Conclusions: Age/sex-specific thresholds improve FIT accuracy with modest increases in colonoscopy demand.Impact: Colonoscopy-capacity-adjusted and age/sex-specific f-Hb thresholds may be useful in optimizing individual screening programs based on detection accuracy, population characteristics, and clinical capacity. Cancer Epidemiol Biomarkers Prev; 27(6); 704-9. ©2018 AACR.

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.

Evaluation of a fecal immunochemistry test prior to colonoscopy for outpatients with various indications

BACKGROUND

Stool tests can predict advanced neoplasms prior to colonoscopy. Results of immunochemical stool tests to predict findings at colonoscopy for various indications are less often reported. We compared pre-colonoscopy stool tests with findings in patients undergoing colonoscopy for different indications.

PATIENTS AND METHODS

Charts of patients undergoing elective or semi-urgent colonoscopy were reviewed. Comparison of adenoma detection rates and pathological findings was made between prescreened and non-prescreened, and between stool-positive and stool-negative cases. Demographics, quality of colonoscopy, and pathological findings were recorded. Odds ratios (ORs) and 95% confidence intervals (CIs) were assessed. Statistical significance was accepted at p≤0.05.

RESULTS

Charts of 325 patients were reviewed. Among them, stool tests were done on 144 patients: 114 were negative and 30 were positive. Findings were similar in the pretest and non-pretest groups. Detection of advanced adenomas per patient was higher in the stool-positive group compared to the stool-negative group (23.4% vs 3.5%, p=0.0016, OR =7.6 [95% CI: 2-29.3]). Five advanced adenomas (without high-grade dysplasia or adenocarcinoma) and several cases of multiple adenomas were missed in the negative group. Sensitivity and specificity for advanced polyps was 63.6% and 82.7%, respectively. The negative predictive value was 96.5%. Male gender was independently predictive of any adenoma.

CONCLUSION

The stool immunochemical test best predicted advanced neoplasms and had a high negative predictive value in this small cohort. Whether this test can be applied to determine the need for colonoscopy in groups other than average risk would require more studies.

Preliminary Results: Colorectal Cancer Screening Using Fecal Immunochemical Test (FIT) in a Thai Population Aged 45-74 Years: A Population-Based Randomized Controlled Trial

Objective:

The aim of this paper is to provide some details and the results to date of a colorectal cancer screening trial using a fecal immunochemical test (FIT).

Methods:

A population-based randomized controlled trial began in May, 2016. All people aged 45 to 74 years living in Nam Phong District, Khon Kaen Province, Thailand, and willing to participate are being recruited using an outreach method. Enrolled participants are randomly allocated by a computer-generated randomization program either to a study arm (receive sample kit for FIT) or to a control arm (no provision of kit). Positive FIT cases are subsequently confirmed by a colonoscopy examination, and negative FIT cases are re-tested with FIT every two years. The preliminary results to date were analysed using descriptive statistics.

Results:

A total of 1,060 enrolled participants provided a complete set of data. Of those randomly assigned to the study arm and tested by FIT, 92 (8.7%) were found to be positive, 39 (11.5%) males and 53 (7.4%) females. The f-Hb concentrations at the 75th, 90th and 95th percentiles for all age groups were higher in males than in females, and the distributions of f-Hb concentration varied with age, especially at the 95th percentile where f-Hb concentrations increased with age.

Conclusion:

The preliminary results of our screening trial have indicated that the prevalence of positive FIT cases is higher than in a similar recent and, at the time unique, previous study in Thailand. This finding is especially the case for males and those in the older age groups.

Colorectal cancer, screening and primary care: A mini literature review

Colorectal cancer (CRC) is a common health problem, representing the third most commonly diagnosed cancer worldwide and causing a significant burden in terms of morbidity and mortality, with annual deaths estimated at 700000. The western way of life, that is being rapidly adopted in many regions of the world, is a well discussed risk factor for CRC and could be targeted in terms of primary prevention. Furthermore, the relatively slow development of this cancer permits drastic reduction of incidence and mortality through secondary prevention. These facts underlie primary care physicians (PCPs) being assigned a key role in health strategies that enhance prevention and prompt diagnosis. Herein, we review the main topics of CRC in the current literature, in order to better understand its pathogenesis, risk and protective factors, as well as screening techniques. Furthermore, we discuss preventive and screening policies to combat CRC and the crucial role served by PCPs in their successful implementation. Relevant articles were identified through electronic searches of MEDLINE and through manual searches of reference lists.

Immunochemical faecal occult blood testing to screen for colorectal cancer: can the screening interval be extended?

OBJECTIVE

Colorectal cancer (CRC) screening programmes based on faecal immunochemical testing for haemoglobin (FIT) typically use a screening interval of 2 years. We aimed to estimate how alternative FIT strategies that use a lower than usual positivity threshold followed by a longer screening interval compare with conventional strategies.

METHODS

We analysed longitudinal data of 4523 Dutch individuals (50-74 years at baseline) participating in round I of a one-sample FIT screening programme, of which 3427 individuals also participated in round II after 1-3 years. The cohort was followed until 2 years after round II. In both rounds, a cut-off level of ≥50 ng haemoglobin (Hb)/mL buffer (corresponding to 10 µg Hb/g faeces) was used, representing the standard scenario. We determined the cumulative positivity rate (PR) and the numbers of subjects diagnosed with advanced adenomas (N_AdvAd) and early stage CRC (N_earlyCRC) in the cohort over two rounds of screening (standard scenario) and compared it with hypothetical single-round screening with use of a lower cut-off and omission of the second round (alternative scenario).

RESULTS

In the standard scenario, the cumulative (ie, round I and II combined) PR, N_AdvAd and N_earlyCRC were 13%, 180% and 26%, respectively. In alternative scenarios using a cut-off level of respectively ≥11 and ≥22 ng/HbmL buffer (corresponding to 2 and 4 µg Hb/g faeces), the PRs were 18% and 13%, the N_AdvAd were 180 and 162 and the N_earlyCRC ranged between 22-27 and 22-26.

CONCLUSIONS

The diagnostic yield of FIT screening using a lowered positivity threshold in combination with an extended screening interval (up to 5 years) may be similar to conventional FIT strategies. This justifies and motivates further research steps in this direction.

CMOST: an open-source framework for the microsimulation of colorectal cancer screening strategies

BACKGROUND

Colorectal cancer (CRC) is a leading cause of cancer-related mortality. CRC incidence and mortality can be reduced by several screening strategies, including colonoscopy, but randomized CRC prevention trials face significant obstacles such as the need for large study populations with long follow-up. Therefore, CRC screening strategies will likely be designed and optimized based on computer simulations. Several computational microsimulation tools have been reported for estimating efficiency and cost-effectiveness of CRC prevention. However, none of these tools is publicly available. There is a need for an open source framework to answer practical questions including testing of new screening interventions and adapting findings to local conditions.

METHODS

We developed and implemented a new microsimulation model, Colon Modeling Open Source Tool (CMOST), for modeling the natural history of CRC, simulating the effects of CRC screening interventions, and calculating the resulting costs. CMOST facilitates automated parameter calibration against epidemiological adenoma prevalence and CRC incidence data.

RESULTS

Predictions of CMOST were highly similar compared to a large endoscopic CRC prevention study as well as predictions of existing microsimulation models. We applied CMOST to calculate the optimal timing of a screening colonoscopy. CRC incidence and mortality are reduced most efficiently by a colonoscopy between the ages of 56 and 59; while discounted life years gained (LYG) is maximal at 49-50 years. With a dwell time of 13 years, the most cost-effective screening is at 59 years, at $17,211 discounted USD per LYG. While cost-efficiency varied according to dwell time it did not influence the optimal time point of screening interventions within the tested range.

CONCLUSIONS

Predictions of CMOST are highly similar compared to a randomized CRC prevention trial as well as those of other microsimulation tools. This open source tool will enable health-economics analyses in for various countries, health-care scenarios and CRC prevention strategies. CMOST is freely available under the GNU General Public License at https://gitlab.com/misselwb/CMOST.

Cost-effectiveness of high-sensitivity faecal immunochemical test and colonoscopy screening for colorectal cancer

BACKGROUND

Colorectal cancer screening can decrease morbidity and mortality. However, there are widespread differences in the implementation of programmes and choice of strategy. The primary objective of this study was to estimate lifelong costs and health outcomes of two of the currently most preferred methods of screening for colorectal cancer: colonoscopy and sensitive faecal immunochemical test (FIT).

METHODS

A cost-effectiveness analysis of colorectal cancer screening in a Swedish population was performed using a decision analysis model, based on the design of the Screening of Swedish Colons (SCREESCO) study, and data from the published literature and registries. Lifelong cost and effects of colonoscopy once, colonoscopy every 10 years, FIT twice, FIT biennially and no screening were estimated using simulations.

RESULTS

For 1000 individuals invited to screening, it was estimated that screening once with colonoscopy yielded 49 more quality-adjusted life-years (QALYs) and a cost saving of €64 800 compared with no screening. Similarly, screening twice with FIT gave 26 more QALYs and a cost saving of €17 600. When the colonoscopic screening was repeated every tenth year, 7 additional QALYs were gained at a cost of €189 400 compared with a single colonoscopy. The additional gain with biennial FIT screening was 25 QALYs at a cost of €154 300 compared with two FITs.

CONCLUSION

All screening strategies were cost-effective compared with no screening. Repeated and single screening strategies with colonoscopy were more cost-effective than FIT when lifelong effects and costs were considered. However, other factors such as patient acceptability of the test and availability of human resources also have to be taken into account.

Recommendations on Fecal Immunochemical Testing to Screen for Colorectal Neoplasia: A Consensus Statement by the US Multi-Society Task Force on Colorectal Cancer

The use of the fecal occult blood test (FOBT) for colorectal cancer (CRC) screening is supported by randomized trials demonstrating effectiveness in cancer prevention and widely recommended by guidelines for this purpose. The fecal immunochemical test (FIT), as a direct measure of human hemoglobin in stool has a number of advantages relative to conventional FOBT and is increasingly used relative to that test. This review summarizes current evidence for FIT in colorectal neoplasia detection and the comparative effectiveness of FIT relative to other commonly used CRC screening modalities. Based on evidence, guidance statements on FIT application were developed and quality metrics for program implementation proposed.

Colorectal cancer surveillance in Hodgkin lymphoma survivors at increased risk of therapy-related colorectal cancer: study design

Background

Second primary malignancies are a major cause of excess morbidity and mortality in cancer survivors. Hodgkin lymphoma survivors who were treated with infradiaphragmatic radiotherapy and/or high-dose procarbazine have an increased risk to develop colorectal cancer.

Colonoscopy surveillance plays an important role in colorectal cancer prevention by removal of the precursor lesions (adenomas) and early detection of cancer, resulting in improved survival rates. Therefore, Hodgkin lymphoma survivors treated with infradiaphragmatic radiotherapy and/or high-dose procarbazine could benefit from colonoscopy, or other surveillance modalities, which are expected to reduce colorectal cancer incidence and mortality. Current knowledge on clinicopathological and molecular characteristics of therapy-related colorectal cancer is limited. The pathogenesis of such colorectal cancers might be different from the pathogenesis in the general population and therefore these patients might require a different clinical approach.

We designed a study with the primary aim to assess the diagnostic yield of a first surveillance colonoscopy among Hodgkin lymphoma survivors at increased risk of colorectal cancer and to compare these results with different screening modalities in the general population. Secondary aims include assessment of the test characteristics of stool tests and evaluation of burden, acceptance and satisfaction of CRC surveillance through two questionnaires.

Methods/Design

This prospective multicenter cohort study will include Hodgkin lymphoma survivors who survived ≥8 years after treatment with infradiaphragmatic radiotherapy and/or procarbazine (planned inclusion of 259 participants). Study procedures will consist of a surveillance colonoscopy with removal of precursor lesions (adenomas) and 6–8 normal colonic tissue biopsies, a fecal immunochemical test and a stool DNA test. All neoplastic lesions encountered will be classified using relevant histomorphological, immunohistochemical and molecular analyses in order to obtain more insight into colorectal carcinogenesis in Hodgkin lymphoma survivors. The Miscan-model will be used for cost-effectiveness analyses.

Discussion

Evaluation of the diagnostic performance, patient acceptance and burden of colorectal cancer surveillance is necessary for future implementation of an individualized colorectal cancer surveillance program for Hodgkin lymphoma survivors. In addition, more insight into treatment-induced colorectal carcinogenesis will provide the first step towards prevention and personalized treatment. This information may be extrapolated to other groups of cancer survivors.

Trial registration

Registered at the Dutch Trial Registry (NTR): NTR4961.

Attendance and diagnostic yield of repeated two-sample faecal immunochemical test screening for colorectal cancer

OBJECTIVE

Limited data exist on attendance and additional yield of 2-sample faecal immunochemical testing (FIT) screening during multiple rounds. We therefore conducted a population-based colorectal cancer screening trial comparing attendance and yield of repeated 1-sample and 2-sample FIT screenings.

DESIGN

Two randomly selected groups of average-risk subjects aged 50-74 years were invited for two rounds of either 1-sample (n=5007) or 2-sample (n=3197) FIT (OC-sensor Micro) screening. The test was considered positive if at least one sample was positive (cut-off 50 ng/mL; 10 µg haemoglobin/g).

RESULTS

The cumulative attendance rate was similar for repeated 1-sample and 2-sample FIT screenings (1-sample FIT: 68.1%; 2-sample FIT: 67.1%, p=0.368). The positivity rate in the second round was lower for 1-sample FIT (6.2%, 95% CI 5.4% to 7.2%) than for 2-sample FIT (8.4%, 95% CI 7.1% to 9.8%, p=0.007), whereas the detection rate of advanced neoplasia (AN, 1-sample FIT: 1.9%, 95% CI 1.2% to 2.2%; 2-sample FIT: 1.7%, 95% CI 1.2% to 2.5%, p=0.861) and the positive predictive value (1-sample FIT: 32%, 95% CI 24% to 40%; 2-sample FIT: 21%, 95% CI 15% to 29%, p=0.075) did not differ. After two rounds of screening, the cumulative diagnostic yield of AN for 1-sample FIT was 29.3 per 1000 invitees, compared with 34.0 for 2-sample FIT (p=0.241).

CONCLUSIONS

Using 2-sample FIT instead of 1-sample FIT does not result in a higher detection rate of AN in the second round of repeated FIT screening. Furthermore, both strategies lead to a similar yield of AN over two rounds. These findings imply that 1-sample FIT screening is preferred over 2-sample FIT screening.

Colorectal cancer screening: Opportunities to improve uptake, outcomes, and disparities

Colorectal cancer screening has become a standard of care in industrialized nations for those 50 to 75 years of age, along with selected high-risk populations. While colorectal cancer screening has been shown to reduce both the incidence and mortality of colorectal cancer, it is a complex multi-disciplinary process with a number of important steps that require optimization before tangible improvements in outcomes are possible. For both opportunistic and programmatic colorectal cancer screening, poor participant uptake remains an ongoing concern. Furthermore, current screening modalities (such as the guaiac based fecal occult blood test, fecal immunochemical test and colonoscopy) may be used or performed suboptimally, which can lead to missed neoplastic lesions and unnecessary endoscopic evaluations. The latter poses the risk of adverse events, such as perforation and post-polypectomy bleeding, as well as financial impacts to the healthcare system. Moreover, ongoing disparities in colorectal cancer screening persist among marginalized populations, including specific ethnic minorities (African Americans, Hispanics, Asians, Indigenous groups), immigrants, and those who are economically disenfranchised. Given this context, we aimed to review the current literature on these important areas pertaining to colorectal cancer screening, particularly focusing on the guaiac based fecal occult blood test, the fecal immunochemical test and colonoscopy.

Effects of Increasing Screening Age and Fecal Hemoglobin Cutoff Concentrations in a Colorectal Cancer Screening Program

BACKGROUND & AIMS

Several countries have implemented programs to screen for colorectal cancer (CRC) by using the fecal immunochemical test (FIT). These programs vary considerably in age of the population screened and the cutoff concentration of fecal hemoglobin (Hb) used to identify candidates for further evaluation; these variations are usually based on a country's colonoscopy resources. We calculated how increasing the Hb cutoff concentration and screening age affects colonoscopy yield, missed lesions, and demand.

METHODS

We collected data from 10,008 average-risk individuals in The Netherlands, 50-74 years old, who were invited for an FIT in the first round of a population-based CRC screening program from November 2006 through December 2008. Fecal samples were collected, and levels of Hb were measured by using the OC-sensor Micro analyzer; concentrations ≥10 μg Hb/g feces were considered positive. Subjects with a positive FIT were scheduled for colonoscopy within 4 weeks. Logistic regression analysis was performed to evaluate the association between age and detection of advanced neoplasia.

RESULTS

In total, 5986 individuals (62%) participated in the study; 503 (8.4%) had a positive test result. Attendance, positive test results, detection of advanced neoplasia, and the FIT's positive predictive value all increased significantly with age (P < .001). Detection of advanced neoplasia ranged from 1.3% in the youngest age group to 6.2% in the oldest group; the positive predictive value of the FIT was 26% in the youngest group and 47% in the oldest group. Increasing the starting age of invitees from 50-74 years to 55-74 years reduced the proportion of subjects who underwent colonoscopy evaluation by 14% and resulted in 9% more subjects with advanced neoplasia being missed. Increasing the cutoff concentration from 10 to 15 μg Hb/g feces reduced the proportion of subjects who underwent colonoscopy evaluation by 11% and resulted in 6% of advanced neoplasia being missed.

CONCLUSIONS

In an analysis of an average-risk screening population in The Netherlands, we found that detection of advanced neoplasia by FIT increases significantly with age and fecal Hb cutoff concentration. Increasing the cutoff concentration or screening age reduces the numbers of patients who undergo colonoscopy evaluation in FIT-based CRC screening programs. Our findings provide insight in these effects per age category and cutoff concentration and the consequences in terms of missed lesions.

Resilience of a FIT screening programme against screening fatigue: a modelling study

Background

Repeated participation is important in faecal immunochemical testing (FIT) screening for colorectal cancer (CRC). However, a large number of screening invitations over time may lead to screening fatigue and consequently, decreased participation rates. We evaluated the impact of screening fatigue on overall screening programme effectiveness.

Methods

Using the ASCCA model, we simulated the Dutch CRC screening programme consisting of biennial FIT screening in individuals aged 55–75. We studied the resilience of the programme against heterogeneity in screening attendance and decrease in participation rate due to screening fatigue. Outcomes were reductions in CRC incidence and mortality compared to no screening.

Results

Assuming a homogenous 63 % participation, i.e., each round each individual was equally likely to attend screening, 30 years of screening reduced CRC incidence and mortality by 39 and 53 %, respectively, compared to no screening. When assuming clustered participation, i.e., three subgroups of individuals with a high (95 %), moderate (65 %) and low (5 %) participation rate, screening was less effective; reductions were 33 % for CRC incidence and 43 % for CRC mortality. Screening fatigue considerably reduced screening effectiveness; if individuals refrained from screening after three negative screens, model-predicted incidence reductions decreased to 25 and 18 % under homogenous and clustered participation, respectively. Figures were 34 and 25 % for mortality reduction.

Conclusions

Screening will substantially decrease CRC incidence and mortality. However, screening effectiveness can be seriously compromised if screening fatigue occurs. This warrants careful monitoring of individual screening behaviour and consideration of targeted invitation systems in individuals who have (repeatedly) missed screening rounds.

Cost-effectiveness and budget impact analysis of a population-based screening program for colorectal cancer

BACKGROUND

Colorectal cancer (CRC) is one of the leading causes of cancer mortality in Belgium. In Flanders (Belgium), a population-based screening program with a biennial immunochemical faecal occult blood test (iFOBT) in women and men aged 56-74 has been organised since 2013. This study assessed the cost-effectiveness and budget impact of the colorectal population-based screening program in Flanders (Belgium).

METHODS

A health economic model was conducted, consisting of a decision tree simulating the screening process and a Markov model, with a time horizon of 20years, simulating natural progression. Predicted mortality and incidence, total costs, and quality-adjusted life-years (QALYs) with and without the screening program were calculated in order to determine the incremental cost-effectiveness ratio of CRC screening. Deterministic and probabilistic sensitivity analyses were conducted, taking into account uncertainty of the model parameters.

RESULTS

Mortality and incidence were predicted to decrease over 20years. The colorectal screening program in Flanders is found to be cost-effective with an ICER of 1681/QALY (95% CI -1317 to 6601) in males and €4,484/QALY (95% CI -3254 to 18,163). The probability of being cost-effective given a threshold of €35,000/QALY was 100% and 97.3%, respectively. The budget impact analysis showed the extra cost for the health care payer to be limited.

CONCLUSION

This health economic analysis has shown that despite the possible adverse effects of screening and the extra costs for the health care payer and the patient, the population-based screening program for CRC in Flanders is cost-effective and should therefore be maintained.

Calibrating Parameters for Microsimulation Disease Models: A Review and Comparison of Different Goodness-of-Fit Criteria

BACKGROUND

Calibration (estimation of model parameters) compares model outcomes with observed outcomes and explores possible model parameter values to identify the set of values that provides the best fit to the data. The goodness-of-fit (GOF) criterion quantifies the difference between model and observed outcomes. There is no consensus on the most appropriate GOF criterion, because a direct performance comparison of GOF criteria in model calibration is lacking.

METHODS

We systematically compared the performance of commonly used GOF criteria (sum of squared errors [SSE], Pearson chi-square, and a likelihood-based approach [Poisson and/or binomial deviance functions]) in the calibration of selected parameters of the MISCAN-Colon microsimulation model for colorectal cancer. The performance of each GOF criterion was assessed by comparing the 1) root mean squared prediction error (RMSPE) of the selected parameters, 2) computation time of the calibration procedure of various calibration scenarios, and 3) impact on estimated cost-effectiveness ratios.

RESULTS

The likelihood-based deviance resulted in the lowest RMSPE in 4 of 6 calibration scenarios and was close to best in the other 2. The SSE had a 25 times higher RMSPE in a scenario with considerable differences in the values of observed outcomes, whereas the Pearson chi-square had a 60 times higher RMSPE in a scenario with multiple studies measuring the same outcome. In all scenarios, the SSE required the most computation time. The likelihood-based approach estimated the cost-effectiveness ratio most accurately (up to -0.15% relative difference versus 0.44% [SSE] and 13% [Pearson chi-square]).

CONCLUSIONS

The likelihood-based deviance criteria lead to accurate estimation of parameters under various circumstances. These criteria are recommended for calibration in microsimulation disease models in contrast with other commonly used criteria.

Different modalities for colorectal cancer screening: experiences in The Netherlands so far

In 2014, a nation-wide colorectal cancer (CRC) screening program was launched in The Netherlands. Every 2 years, men and women aged 55–75 years will be invited to participate in fecal immunochemical test screening. Participants with a positive test result will be scheduled for colonoscopy. Starting from 2006, screening pilots have been performed to ascertain the choice of an optimal screening modality, population acceptance, logistics and cost effectiveness, in order to ensure that a screening program with maximal benefits and the least amount of harms was offered to the Dutch population. In this overview, we will discuss the results of Dutch CRC screening pilots in which different screening modalities were studied, the preparations made before the launch of the nation-wide screening program, and finally the initial results and lessons learned so far from the Dutch CRC screening program.