Colorectal cancer screening with faecal testing, sigmoidoscopy or colonoscopy: a systematic review and network meta-analysis

Optical diagnosis in still images of colorectal polyps: comparison between expert endoscopists and PolyDeep, a Computer-Aided Diagnosis system

Background

PolyDeep is a computer-aided detection and classification (CADe/x) system trained to detect and classify polyps. During colonoscopy, CADe/x systems help endoscopists to predict the histology of colonic lesions.

Objective

To compare the diagnostic performance of PolyDeep and expert endoscopists for the optical diagnosis of colorectal polyps on still images.

Methods

PolyDeep Image Classification (PIC) is an in vitro diagnostic test study. The PIC database contains NBI images of 491 colorectal polyps with histological diagnosis. We evaluated the diagnostic performance of PolyDeep and four expert endoscopists for neoplasia (adenoma, sessile serrated lesion, traditional serrated adenoma) and adenoma characterization and compared them with the McNemar test. Receiver operating characteristic curves were constructed to assess the overall discriminatory ability, comparing the area under the curve of endoscopists and PolyDeep with the chi- square homogeneity areas test.

Results

The diagnostic performance of the endoscopists and PolyDeep in the characterization of neoplasia is similar in terms of sensitivity (PolyDeep: 89.05%; E1: 91.23%, p=0.5; E2: 96.11%, p<0.001; E3: 86.65%, p=0.3; E4: 91.26% p=0.3) and specificity (PolyDeep: 35.53%; E1: 33.80%, p=0.8; E2: 34.72%, p=1; E3: 39.24%, p=0.8; E4: 46.84%, p=0.2). The overall discriminative ability also showed no statistically significant differences (PolyDeep: 0.623; E1: 0.625, p=0.8; E2: 0.654, p=0.2; E3: 0.629, p=0.9; E4: 0.690, p=0.09). In the optical diagnosis of adenomatous polyps, we found that PolyDeep had a significantly higher sensitivity and a significantly lower specificity. The overall discriminative ability of adenomatous lesions by expert endoscopists is significantly higher than PolyDeep (PolyDeep: 0.582; E1: 0.685, p < 0.001; E2: 0.677, p < 0.0001; E3: 0.658, p < 0.01; E4: 0.694, p < 0.0001).

Conclusion

PolyDeep and endoscopists have similar diagnostic performance in the optical diagnosis of neoplastic lesions. However, endoscopists have a better global discriminatory ability than PolyDeep in the optical diagnosis of adenomatous polyps.

Colorectal cancer screening with fecal immunochemical testing or primary colonoscopy: inequities in diagnostic yield

BACKGROUND

Socioeconomic inequalities in the uptake of colorectal cancer screening are well documented, but the implications on inequities in health gain remain unclear.

METHODS

Sixty-year-olds were randomly recruited from the Swedish population between March 2014 and March 2020 and invited to undergo either 2 rounds of fecal immunochemical testing (FIT) 2 years apart (n = 60 137) or primary colonoscopy just once (n = 30 400). By linkage to Statistics Sweden's registries, we obtained socioeconomic data. In each defined socioeconomic group, we estimated the cumulative yield of advanced neoplasia in each screening arm (intention-to-screen analysis). In the biennial FIT arm, we predicted the probability of exceeding the yield in the primary colonoscopy arm by linear extrapolation of the cumulative yield to (hypothetical) additional rounds of FIT.

RESULTS

In the lowest income group, the yield of advanced neoplasia was 1.63% (95% confidence interval [CI] = 1.35% to 1.93%) after 2 rounds of FIT vs 1.93% (95% CI = 1.49% to 2.40%) in the primary colonoscopy arm. Extrapolation to a third round of FIT implied a 86% probability of exceeding the yield in the primary colonoscopy arm. In the highest income group, we found a more pronounced yield gap between the 2 screening strategies-2.32% (95% CI = 2.15% to 2.49%) vs 3.71% (95% CI = 3.41% to 4.02%)- implying a low (2%) predicted probability of exceeding yield after a third round of FIT.

CONCLUSIONS

Yield of advanced neoplasia from 2 rounds of FIT 2 years apart was poorer as compared with primary colonoscopy, but the difference was less in lower socioeconomic groups.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT02078804.

Multilevel analysis of social determinants of advanced stage colorectal cancer diagnosis

The advanced stage at diagnosis of colorectal cancer (CRC) may be related to individual factors, socioeconomic conditions, and healthcare service availability. The objective of the study was to analyze the prevalence of advanced stage CRC at the time of diagnosis and its association with individual, contextual, socioeconomic, and healthcare service indicators. An observational, cross-sectional study was conducted, analyzing cases of malignant neoplasms of the colon and rectum in individuals of both sexes, aged between 18 and 99 years, diagnosed between 2010 and 2019 in Brazil (n = 69,047). Data were collected from the Hospital Cancer Registry (HCR), Atlas of Human Development in Brazil, and from the National Registry of Health Institutions (NRHI). A Multilevel Poisson Regression model with random intercept was used. The prevalence of advanced stage CRC at diagnosis was 65.6%. Advanced stage was associated with older age groups prevalence ratio (PR) 4.40 and younger age groups (PR 1.84), low Human Development Index (HDI) (PR 1.22), and low density of family health strategy teams (PR 1.10). The study highlights the unequal distribution of social determinants of health in the diagnosis CRC in Brazil, revealing the need to evaluate and redirect public policies aimed at improving early detection and prevention of CRC in the country.

Should we perform sigmoidoscopy for colorectal cancer screening in people under 45 years?

BACKGROUND

The strategy for preventing colorectal cancer is screening by colonoscopy, which offers a direct way for detection and removal of adenomatous polyps (APs). American College of Gastroenterology guidelines recommend that people aged ≥ 45 years should undergo colonoscopy; however, how to deal with people aged ≤ 45 years is still unknown.

AIM

To compare the prevalence of APs and high-grade neoplasia between the left and right colon in patients ≤ 45 years.

METHODS

A retrospective observational study was conducted at a single tertiary III hospital in China. This study included patients aged 18-45 years with undergoing initial colonoscopy dissection and pathological diagnosis AP or high-grade neoplasia between February 2014 and January 2021. The number of APs in the entire colon while screening and post-polypectomy surveillance in following 1-3 years were evaluated.

RESULTS

A total of 3053 cases were included. The prevalence of APs in the left and right colon was 55.0% and 41.6%, respectively (OR 1.7, 95%CI 1.6-2.4; P < 0.05). For APs with high-grade neoplasia, the prevalence was 2.7% and 0.9%, respectively (OR 3.0, 95%CI 2.0-4.6; P < 0.05). Therefore, the prevalence of APs and high-grade neoplasia in the left colon was significantly higher than in the right colon in patients aged ≤ 45 years. There were 327 patients who voluntarily participated in post-polypectomy surveillance in following 1-3 years, and APs were found in 216 cases (66.1%); 170 cases had 1-3 polyps (52.0%) and 46 cases had > 3 polyps (14.1%; OR 0.3, 95%CI 0.1-0.6; P < 0.05).

CONCLUSION

This study suggests that flexible sigmoidoscopy would be an optimal approach for initial screening in people aged ≤ 45 years and would be a more cost-effective and safe strategy.

Colorectal cancer screening: A review of current knowledge and progress in research

Colorectal cancer (CRC) is one of the most prevalent malignancies worldwide, being the third most commonly diagnosed malignancy and the second leading cause of cancer-related deaths globally. Despite the progress in screening, early diagnosis, and treatment, approximately 20%-25% of CRC patients still present with metastatic disease at the time of their initial diagnosis. Furthermore, the burden of disease is still expected to increase, especially in individuals younger than 50 years old, among whom early-onset CRC incidence has been increasing. Screening and early detection are pivotal to improve CRC-related outcomes. It is well established that CRC screening not only reduces incidence, but also decreases deaths from CRC. Diverse screening strategies have proven effective in decreasing both CRC incidence and mortality, though variations in efficacy have been reported across the literature. However, uncertainties persist regarding the optimal screening method, age intervals and periodicity. Moreover, adherence to CRC screening remains globally low. In recent years, emerging technologies, notably artificial intelligence, and non-invasive biomarkers, have been developed to overcome these barriers. However, controversy exists over the actual impact of some of the new discoveries on CRC-related outcomes and how to effectively integrate them into daily practice. In this review, we aim to cover the current evidence surrounding CRC screening. We will further critically assess novel approaches under investigation, in an effort to differentiate promising innovations from mere novelties.

Trends in mortality from gastrointestinal, hepatic, and pancreatic cancers in the United States: A comprehensive analysis (1999-2020)

Background and Aim

This study investigates temporal trends in gastrointestinal cancer-related mortality in the United States between 1999 and 2020, focusing on differences by sex, age, and race.

Methods

We investigated the Centers for Disease Control and Prevention Wide-Ranging Online Data for Epidemiologic Research multiple causes of death database (Years 1999-2020) for gastrointestinal cancer-related mortality with a focus on the underlying cause of death.

Results

A total of 3 115 243 gastrointestinal cancer-related deaths occurred from 1999 to 2020. The overall age-adjusted mortality rate decreased from 46.7 per 100 000 in 1999 to 38.4 per 100 000 in 2020. The average annual percent change (AAPC) for the study period was -0.9% (95% CI: -1.0%, -0.9%, P < 0.001), with no significant difference in AAPC between the sexes but some difference between races and related to individual cancers. African Americans and Asian Americans, and Pacific Islanders experienced a greater decrease in mortality compared with Whites. Mortality rates for American Indian and Alaskan Native populations also decreased significantly from 1999 to 2020 (P < 0.001). There were significant declines in esophageal, stomach, colon, rectal, and gallbladder cancer-related mortality but increases in the small bowel, anal, pancreatic, and hepatic cancer-related mortality (P < 0.001), with variation across different sexes and racial groups.

Conclusion

While overall gastrointestinal cancer-related mortality declined significantly in the United States from 1999 to 2020, mortality from some cancers increased. Furthermore, differences between sexes and racial groups underscore crucial differences in gastrointestinal cancer mortality, highlighting areas for future research.

Deaths and cardiopulmonary events following colorectal cancer screening-A systematic review with meta-analyses

BACKGROUND

Colorectal cancer screening programmes (CRCSPs) are implemented worldwide despite recent evidence indicating more physical harm occurring during CRCSPs than previously thought. Therefore, we aimed to review the evidence on physical harms associated with endoscopic diagnostic procedures during CRCSPs and, when possible, to quantify the risk of the most serious types of physical harm during CRCSPs, i.e. deaths and cardiopulmonary events (CPEs).

METHODS

Systematic review with descriptive statistics and random-effects meta-analyses of studies investigating physical harms following CRCSPs. We conducted a systematic search in the literature and assessed the risk of bias and the certainty of the evidence.

RESULTS

We included 134 studies for review, reporting findings from 151 unique populations when accounting for multiple screening interventions per study. Physical harm can be categorized into 17 types of harm. The evidence was very heterogeneous with inadequate measurement and reporting of harms. The risk of bias was serious or critical in 95% of assessments of deaths and CPEs, and the certainty of the evidence was very low in all analyses. The risk of death was assessed for 57 populations with large variation across studies. Meta-analyses indicated that 3 to 23 deaths occur during CRCSPs per 100,000 people screened. Cardiopulmonary events were assessed for 55 populations. Despite our efforts to subcategorize CPEs into 17 distinct subtypes, 41% of CPE assessments were too poorly measured or reported to allow quantification. We found a tendency towards lower estimates of deaths and CPEs in studies with a critical risk of bias.

DISCUSSION

Deaths and CPEs during CRCSPs are rare, yet they do occur during CRCSPs. We believe that our findings are conservative due to the heterogeneity and low quality of the evidence. A standardized system for the measurement and reporting of the harms of screening is warranted.

TRIAL REGISTRATION

PROSPERO Registration number CRD42017058844.

Screening for liver fibrosis: lessons from colorectal and lung cancer screening

Many countries have incorporated population screening programmes for cancer, such as colorectal and lung cancer, into their health-care systems. Cirrhosis is more prevalent than colorectal cancer and has a comparable age-standardized mortality rate to lung cancer. Despite this fact, there are no screening programmes in place for early detection of liver fibrosis, the precursor of cirrhosis. In this Perspective, we use insights from colorectal and lung cancer screening to explore the benefits, challenges, implementation strategies and pathways for future liver fibrosis screening initiatives. Several non-invasive methods and referral pathways for early identification of liver fibrosis exist, but in addition to accurate detection, screening programmes must also be cost-effective and demonstrate benefit through a reduction in liver-related mortality. Randomized controlled trials are needed to confirm this. Future randomized screening trials should evaluate not only the screening tests, but also interventions used to halt disease progression in individuals identified through screening.

Effectiveness of Colonoscopy Screening vs Sigmoidoscopy Screening in Colorectal Cancer

Importance

Randomized clinical screening trials have shown that sigmoidoscopy screening reduces colorectal cancer (CRC) incidence and mortality. Colonoscopy has largely replaced sigmoidoscopy for CRC screening, but long-term results from randomized trials on colonoscopy screening are still lacking.

Objective

To estimate the additional screening benefit of colonoscopy compared with sigmoidoscopy.

Design, Setting, and Participants

This comparative effectiveness simulation study pooled data on 358 204 men and women randomly assigned to sigmoidoscopy screening or usual care in 4 randomized sigmoidoscopy screening trials conducted in Norway, Italy, the US, and UK with inclusion periods in the years 1993 to 2001. The primary analysis of the study was conducted from January 19 to December 30, 2021.

Intervention

Invitation to endoscopic screening.

Main Outcomes and Measures

Primary outcomes were CRC incidence and mortality. Using pooled 15-year follow-up data, colonoscopy screening effectiveness was estimated assuming that the efficacy of colonoscopy in the proximal colon was similar to that observed in the distal colon in the sigmoidoscopy screening trials. The simulation model was validated using data from Norwegian participants in a colonoscopy screening trial.

Results

This analysis included 358 204 individuals (181 971 women [51%]) aged 55 to 64 years at inclusion with a median follow-up time ranging from 15 to 17 years. Compared with usual care, colonoscopy prevented an estimated 50 (95% CI, 42-58) CRC cases per 100 000 person-years, corresponding to 30% incidence reduction (rate ratio, 0.70 [95% CI, 0.66-0.75]), and prevented an estimated 15 (95% CI, 11-19) CRC deaths per 100 000 person-years, corresponding to 32% mortality reduction (rate ratio, 0.68 [95% CI, 0.61-0.76]). The additional benefit of colonoscopy screening compared with sigmoidoscopy was 12 (95% CI, 10-14) fewer CRC cases and 4 (95% CI, 3-5) fewer CRC deaths per 100 000 person-years, corresponding to percentage point reductions of 6.9 (95% CI, 6.0-7.9) for CRC incidence and 7.6 (95% CI, 5.7-9.6) for CRC mortality. The number needed to switch from sigmoidoscopy to colonoscopy screening was 560 (95% CI, 486-661) to prevent 1 CRC case and 1611 (95% CI, 1275-2188) to prevent 1 CRC death.

Conclusions and Relevance

The findings of this comparative effectiveness study assessing long-term follow-up after CRC screening suggest that there was an additional preventive effect on CRC incidence and mortality associated with colonoscopy screening compared with sigmoidoscopy screening, but the additional preventive effect was less than what was achieved by introducing sigmoidoscopy screening where no screening existed. The results probably represent the upper limit of what may be achieved with colonoscopy screening compared with sigmoidoscopy screening.

Why is early detection of colon cancer still not possible in 2023?

Colorectal cancer (CRC) screening is a fundamental tool in the prevention and early detection of one of the most prevalent and lethal cancers. Over the years, screening, particularly in those settings where it is well organized, has succeeded in reducing the incidence of colon and rectal cancer and improving the prognosis related to them. Despite considerable advancements in screening technologies and strategies, the effectiveness of CRC screening programs remains less than optimal. This paper examined the multifaceted reasons behind the persistent lack of effectiveness in CRC screening initiatives. Through a critical analysis of current methodologies, technological limitations, patient-related factors, and systemic challenges, we elucidated the complex interplay that hampers the successful reduction of CRC morbidity and mortality rates. While acknowledging the advancements that have improved aspects of screening, we emphasized the necessity of addressing the identified barriers comprehensively. This study aimed to raise awareness of how important CRC screening is in reducing costs for this disease. Screening and early diagnosis are not only important in improving the prognosis of patients with CRC but can lead to an important reduction in the cost of treating a disease that is often diagnosed at an advanced stage. Spending more sooner can mean saving money later.

Integrated meta-analysis of colorectal cancer public proteomic datasets for biomarker discovery and validation

The cancer biomarker field has been an object of thorough investigation in the last decades. Despite this, colorectal cancer (CRC) heterogeneity makes it challenging to identify and validate effective prognostic biomarkers for patient classification according to outcome and treatment response. Although a massive amount of proteomics data has been deposited in public data repositories, this rich source of information is vastly underused. Here, we attempted to reuse public proteomics datasets with two main objectives: i) to generate hypotheses (detection of biomarkers) for their posterior/downstream validation, and (ii) to validate, using an orthogonal approach, a previously described biomarker panel. Twelve CRC public proteomics datasets (mostly from the PRIDE database) were re-analysed and integrated to create a landscape of protein expression. Samples from both solid and liquid biopsies were included in the reanalysis. Integrating this data with survival annotation data, we have validated in silico a six-gene signature for CRC classification at the protein level, and identified five new blood-detectable biomarkers (CD14, PPIA, MRC2, PRDX1, and TXNDC5) associated with CRC prognosis. The prognostic value of these blood-derived proteins was confirmed using additional public datasets, supporting their potential clinical value. As a conclusion, this proof-of-the-concept study demonstrates the value of re-using public proteomics datasets as the basis to create a useful resource for biomarker discovery and validation. The protein expression data has been made available in the public resource Expression Atlas.

Impact of organised colorectal cancer screening on age-specific population incidences: evidence from a quasi-experimental study in Sweden

Colorectal cancer (CRC) incurs a significant disease burden globally. Organised CRC screening programmes have been widely implemented for early detection and prevention. To understand the public health impact of these programmes, quantitative evidence of changes in overall and age-specific population incidences is fundamental. We aimed to provide such evidence by exploiting a time lag in the implementation of organised screening in Sweden: two out of 21 regions (these two regions comprise nearly 20% of the total Swedish population) have offered organised screening since 2008; the other regions have offered CRC screening since 2021. Using registry data on diagnosed CRC cases and socio-demographics for all regions in Sweden over the period 1970-2019, Bayesian structural time series modelling and difference-in-differences were applied to analyse the impact of screening on age-specific population incidences over time (CRC cases per 100.000 persons/year). After inviting birth-year cohorts aged 60-69 years for stool-based testing, the incidence rate in the 70-74-year age group decreased significantly over time, with an average reduction of - 44·40 (95% CI - 58·15 to - 31·31) from 2011 to 2019 in the intervention regions. In the overall population aged 60-74 years, there was a net incidence decrease of - 7·99 (95% CI - 13·85 to - 2·39) since the initiation of organised screening in the intervention regions (2008-2019). Organised CRC screening for 60-69-year-olds generated a change in age-specific incidence patterns with a long-lasting incidence decrease in the 70-74-year-old population, implying reductions in the excess mortality and burden of the disease.

Recommandations pour des soins préventifs pour promouvoir l’équité en matière de santé

Contexte:

Malgré des investissements importants dans un système de soins de santé public qui comprend des services préventifs, on continue d’observer des disparités évitables en matière de santé au Canada. L’équipe avait pour objectif de formuler des recommandations pour des soins de santé préventifs qui puissent améliorer l’équité en matière de santé par la priorisation des interventions efficaces à l’intention des groupes défavorisés.

Méthodes:

La ligne directrice a été élaborée par un comité composé de spécialistes en soins primaires et de membres de la patientèle, avec la contribution d’un groupe de patientes-et patientspartenaires ayant vécu diverses expériences. Après avoir sélectionné les sujets à prioriser, nous avons recensé les revues systématiques, les essais randomisés et contrôlés récents sur les méthodes de dépistage et d’autres études pertinentes sur l’efficacité du dépistage et de la prise en charge. Nous avons utilisé l’approche GRADE (Grading of Recommendations, Assessment, Development and Evaluation) pour formuler les recommandations et avons suivi le guide AGREE II (Appraisal of Guidelines for Research and Evaluation) pour rédiger le rapport. Il en a été de même avec les principes du Guidelines International Network pour la gestion des intérêts concurrents. Les recommandations ont été passées en revue par un comité externe d’experts en contenu avant d’être distribuées à des intervenants à l’échelle nationale pour approbation.

Recommandations:

Nous avons formulé 15 recommandations concernant le dépistage et d’autres soins préventifs et 1 recommandation de nature politique visant à améliorer l’accès aux soins primaires. Ainsi, nous recommandons de prioriser une stratégie de communication pour le dépistage du cancer colorectal à partir de l’âge de 45 ans et pour l’évaluation du risque de maladie cardiovasculaire pour lutter contre les iniquités en matière de santé et promouvoir la santé. Les interventions particulières qui devraient être déployées pour lutter contre les iniquités comprennent l’autodépistage du virus du papillome humain (VPH) et du VIH, et le test de libération de l’interféron γ pour l’infection tuberculeuse. Le dépistage de la dépression, de la toxicomanie, de la violence conjugale et de la pauvreté devrait également permettre aux personnes touchées d’accéder plus facilement à des interventions éprouvées. Nous recommandons une prise de contact systématique avec des professionnels de la santé en soins primaires pour les personnes défavorisées.

Interprétation:

Les interventions préventives éprouvées peuvent aider à combattre les iniquités en matière de santé si la priorité est accordée aux personnes défavorisées. Les médecins, les organisations de santé et les gouvernements devraient adopter des mesures fondées sur des données probantes et en faire le suivi s’ils veulent promouvoir l’équité en matière de santé partout au Canada.

Estimated Lifetime Gained With Cancer Screening Tests: A Meta-Analysis of Randomized Clinical Trials

Importance

Cancer screening tests are promoted to save life by increasing longevity, but it is unknown whether people will live longer with commonly used cancer screening tests.

Objective

To estimate lifetime gained with cancer screening.

Data Sources

A systematic review and meta-analysis was conducted of randomized clinical trials with more than 9 years of follow-up reporting all-cause mortality and estimated lifetime gained for 6 commonly used cancer screening tests, comparing screening with no screening. The analysis included the general population. MEDLINE and the Cochrane library databases were searched, and the last search was performed October 12, 2022.

Study Selection

Mammography screening for breast cancer; colonoscopy, sigmoidoscopy, or fecal occult blood testing (FOBT) for colorectal cancer; computed tomography screening for lung cancer in smokers and former smokers; or prostate-specific antigen testing for prostate cancer.

Data Extraction and Synthesis

Searches and selection criteria followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) reporting guideline. Data were independently extracted by a single observer, and pooled analysis of clinical trials was used for analyses.

Main Outcomes and Measures

Life-years gained by screening was calculated as the difference in observed lifetime in the screening vs the no screening groups and computed absolute lifetime gained in days with 95% CIs for each screening test from meta-analyses or single randomized clinical trials.

Results

In total, 2 111 958 individuals enrolled in randomized clinical trials comparing screening with no screening using 6 different tests were eligible. Median follow-up was 10 years for computed tomography, prostate-specific antigen testing, and colonoscopy; 13 years for mammography; and 15 years for sigmoidoscopy and FOBT. The only screening test with a significant lifetime gain was sigmoidoscopy (110 days; 95% CI, 0-274 days). There was no significant difference following mammography (0 days: 95% CI, -190 to 237 days), prostate cancer screening (37 days; 95% CI, -37 to 73 days), colonoscopy (37 days; 95% CI, -146 to 146 days), FOBT screening every year or every other year (0 days; 95% CI, -70.7 to 70.7 days), and lung cancer screening (107 days; 95% CI, -286 days to 430 days).

Conclusions and Relevance

The findings of this meta-analysis suggest that current evidence does not substantiate the claim that common cancer screening tests save lives by extending lifetime, except possibly for colorectal cancer screening with sigmoidoscopy.

Adverse Tumour and Host Biology May Explain the Poorer Outcomes Seen in Emergency Presentations of Colon Cancer

OBJECTIVE

To examine the association between tumor/host factors (including the systemic inflammatory response), mode of presentation, and short/long-term outcomes in patients undergoing curative resectional surgery for TNM I to III colon cancer.

BACKGROUND

Emergency presentations of colon cancer are associated with worse long-term outcomes than elective presentations despite adjustment for TNM stage. A number of differences in tumor and host factors have been identified between elective and emergency presentations and it may be these factors that are associated with adverse outcomes.

METHODS

Patients undergoing curative surgery for TNM I to III colon cancer in the West of Scotland from 2011 to 2014 were identified. Tumor/host factors independently associated with the emergency presentation were identified and entered into a subsequent survival model to determine those that were independently associated with overall survival/cancer-specific survival (OS/CSS).

RESULTS

A total of 2705 patients were identified. The emergency presentation was associated with a worse 3-year OS and CSS compared with elective presentations (70% vs 86% and 91% vs 75%). T stage, age, systemic inflammatory grade, anemia (all P < 0.001), N stage ( P = 0.077), extramural venous invasion ( P = 0.003), body mass index ( P = 0.001), and American Society of Anesthesiologists Classification classification ( P = 0.021) were independently associated with emergency presentation. Of these, body mass index [hazard ratio (HR), 0.82], American Society of Anesthesiologists Classification (HR, 1.45), anemia (HR, 1.29), systemic inflammatory grade (HR. 1.11), T stage (HR, 1.57), N stage (HR, 1.80), and adjuvant chemotherapy (HR, 0.47) were independently associated with OS. Similar results were observed for CSS.

CONCLUSIONS

Within patients undergoing curative surgery for colon cancer, the emergency presentation was not independently associated with worse OS/CSS. Rather, a combination of tumor and host factors account for the worse outcomes observed.

The risk of bleeding and perforation from sigmoidoscopy or colonoscopy in colorectal cancer screening: A systematic review and meta-analyses

INTRODUCTION

Physical harm from Colorectal Cancer Screening tends to be inadequately measured and reported in clinical trials. Also, studies of ongoing Colorectal Cancer Screening programs have found more frequent and severe physical harm from screening procedures, e.g., bleeding and perforation, than reported in previous trials. Therefore, the objectives of the study were to systematically review the evidence on the risk of bleeding and perforation in Colorectal Cancer Screening.

DESIGN

Systematic review with descriptive statistics and random-effects meta-analyses.

METHODS

We systematically searched five databases for studies investigating physical harms related to Colorectal Cancer Screening. We assessed the internal and the external validity using the ROBINS-I tool and the GRADE approach. Harm estimates was calculated using mixed Poisson regression models in random-effect meta-analyses.

RESULTS

We included 89 studies. Reporting and measurement of harms was inadequate in most studies. In effect, the risk of bias was critical in 97.3% and serious in 98.3% of studies. All GRADE ratings were very low. Based on severe findings with not-critical risk of bias and 30 days follow-up, the risk of bleedings per 100,000 people screened were 8 [2;24] for sigmoidoscopy, 229 [129;408] for colonoscopy following fecal immunochemical test, 68 [39;118] for once-only colonoscopy, and 698 [443;1045] for colonoscopy following any screening tests. The risk of perforations was 88 [56;138] for colonoscopy following fecal immunochemical test and 53 [25;112] for once-only colonoscopy. There were no findings within the subcategory severe perforation with long-term follow-up for colonoscopy following any screening tests and sigmoidoscopy.

DISCUSSION

Harm estimates varied widely across studies, reporting and measurement of harms was mostly inadequate, and the risk of bias and GRADE ratings were very poor, collectively leading to underestimation of harm. In effect, we consider our estimates of perforation and bleeding as conservative, highlighting the need for better reporting and measurement in future studies.

TRIAL REGISTRATION

PROSPERO registration number: CRD42017058844.

Participants' satisfaction with colorectal cancer screening programs: A systematic review

INTRODUCTION

Since satisfaction with cancer screening experience can increase adherence to programs and contribute to reduce morbidity and mortality, its assessment is crucial for programs´ effectiveness. Our aim was to conduct a systematic review about satisfaction of participants with organized colorectal cancer screening.

METHODS

We searched relevant scientific databases (MEDLINE, EMBASE, PsycINFO, and CINAHL) from inception to May 2022. We selected cross-sectional studies and clinical trials reporting a quantitative survey-based measure of satisfaction towards CRC screening.

RESULTS

A total of 15 studies were included, being published from 1992 to 2019 for an overall number of 21 surveys. Of those, 16 (76%) investigated satisfaction with screening tests (fecal occult blood test, fecal immunochemical test, sigmoidoscopy, colonoscopy, computed tomographic colonography), 4 (19%) with colonoscopy as assessment test after suspicious findings, and 2 (10%) with both the screening and assessment phase. None of the included surveys used a validated questionnaire. Most surveys reported a high level of satisfaction for both screening and further assessment phases. Temporary pain, discomfort, embarrassment, and anxiety while waiting for results were the commonest negative aspects perceived, with some variability across studies and considered procedures.

CONCLUSIONS

Satisfaction with the information and communication about screening was generally good, but some authors reported participants' sub-optimal understanding of informative material. Satisfaction with CRC screening is generally high, but its evaluation is performed using non-validated instruments, which limits the interpretation of results and prevents comparability of the current body of evidence.

Preventive care recommendations to promote health equity

BACKGROUND

Avoidable disparities in health outcomes persist in Canada despite substantial investments in a publicly funded health care system that includes preventive services. Our objective was to provide preventive care recommendations that promote health equity by prioritizing effective interventions for people experiencing disadvantages.

METHODS

The guideline was developed by a primary care provider-patient panel, with input from a patient-partner panel with diverse lived experiences. After selecting priority topics, we searched for systematic reviews and recent randomized controlled trials of screening and other relevant studies of screening accuracy and management efficacy. We used the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach to develop recommendations and followed the Appraisal of Guidelines for Research and Evaluation (AGREE II) reporting guidance. We managed competing interests using the Guideline International Network principles. The recommendations were externally reviewed by content experts and circulated for endorsement by national stakeholders.

RECOMMENDATIONS

We developed 15 screening and other preventive care recommendations and 1 policy recommendation on improving access to primary care. We recommend prioritized outreach for colorectal cancer screening starting at age 45 years and for cardiovascular disease risk assessment, to help address inequities and promote health. Specific interventions that should be rolled out in ways that address inequities include human papillomavirus (HPV) self-testing, HIV self-testing and interferon-γ release assays for tuberculosis infection. Screening for depression, substance use, intimate partner violence and poverty should help connect people experiencing specific disadvantages with proven interventions. We recommend automatic connection to primary care for people experiencing disadvantages.

INTERPRETATION

Proven preventive care interventions can address health inequities if people experiencing disadvantages are prioritized. Clinicians, health care organizations and governments should take evidence-based actions and track progress in promoting health equity across Canada.

Colonoscopy following the positron emission tomography/computed tomography scan in patients with incidental colorectal uptake: what is the most effective management?

OBJECTIVE

Colorectal cancer is one of the most common malignancies. Survival rates are directly related to the stage of cancer at the time of diagnosis, emphasizing the value of early diagnosis. Positron emission tomography with 18F-fluorodeoxyglucose is the gold standard imaging technique in staging, monitoring after treatment, and follow-up. We aimed to assess the importance of incidental 18F-fluorodeoxyglucose uptake by colon and rectum in positron emission tomography-computed tomography imaging to determine a significant cutoff value for further investigation using colonoscopy and histopathological assessment.

METHODS

We performed a retrospective analysis of patients with both 18F-fluorodeoxyglucose-positron emission tomography/computed tomography scan and colonoscopy during 1 year and included the cases who had undergone a colonoscopy within 3 months following the positron emission tomography/computed tomography scan due to an incidental positive finding. Patients with a diagnosed colorectal malignancy or with a history of previous colorectal operations were excluded.

RESULTS

A total of 81 patients were included in this study. Among 81 colonoscopic evaluations, histopathology revealed malignancy in 8 patients, and the prevalence of incidental colorectal cancer 18F-fluorodeoxyglucose uptake was found to be 9.87%. SUVmax was found to be significantly related to malignancy and other colonoscopic findings (p<0.001). SUVmax cutoff value to suggest colorectal cancer was found to be median [7.9 (4.1-12.7)] (p<0.001).

CONCLUSION

Regarding the studies determining a significant cutoff value, incidental colonic 18F-fluorodeoxyglucose uptake on positron emission tomography/computed tomography should lead the clinician to further investigation with colonoscopic biopsy, although the cutoff values for SUVmax are not certain and different in almost every published study, and negative positron emission tomography.computed tomography findings should not completely rule out malignancy, especially in high-risk patients.

Knowledge, Compliance, and Inequities in Colon Cancer Screening in Spain: An Exploratory Study

In Spain, inequities exist in implementing colorectal cancer (CRC) tests with the target population-adults aged 50 to 69-as part of population-based CRC screening programs. This research aims to further our understanding of the target population's awareness, attitudes, and perceptions of these test-based screening programs. A survey was carried out using an online panel representative of the target population, with a sample collected from 5313 individuals. Data collection took place in June 2022. Descriptive and bivariate analyses were carried out using contingency tables, the Chi-square test, and Cramer's V statistics. The sample was also segmented based on key variables. Finally, the results were analyzed using logistic regression. In the sample population, 62.5% had taken the fecal occult blood test (FOBT), 72.5% reported receiving the invitation letter to participate in the screening program, and 86.8% had prior knowledge of the FOBT. Noncompliance was mainly due to lack of symptoms (40%), non-receipt of invitation letters (39.7%), and forgetfulness or neglect (28.5%). On the contrary, receipt of the letter of invitation (OR 7.35, p < 0.01) and prior knowledge of FOBT (OR 6.32, p < 0.01) were the main variables that increased the probability of test uptake. Other significant variables included frequency of primary care visits (OR 1.71, p < 0.01) and being older (65-69 years old) (OR 1.52, p < 0.01) There is still a pressing need for greater awareness of both CRC risk factors and the benefits of early detection, as well as for overcoming the common misconception that detection should only be sought when symptoms are present.

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.

Effect of a FIT-Based Colorectal Cancer Screening Program on Mortality Estimated by the Regression Discontinuity Design

The fecal immunochemical test (FIT) has been implemented in colorectal cancer (CRC) screening programs, but effect evaluations are lacking. We evaluated the effect of a positive FIT on all-cause and CRC mortality using the regression discontinuity design. The Danish CRC screening program invites all residents 50-74 years old, using a 20-μg hemoglobin/g feces cutoff for colonoscopy referral. In this cohort study, we followed all first-time screening participants from 2014-2019 until 2020. We estimated the local effect of screening results, of just above the cutoff vs. just below, as hazard ratios (HRs) between models fitted at each side of the cutoff. We conducted the analysis within a narrow hemoglobin range (≥17 and <23, n = 16,428) and a wider range (≥14 and <26, n = 35,353). Those screened just above the cutoff had lower all-cause mortality compared with below (HR = 0.87, 95% confidence interval: 0.69; 1.10), estimated from the narrow range. The CRC mortality analysis had few outcomes. In the wider range, those with a FIT just above the cutoff had a lower hazard of CRC mortality compared with just below the cutoff (HR = 0.49, 95% confidence interval: 0.17; 1.41). A FIT result just above the cutoff, leading to referral to colonoscopy, pointed towards reduced all-cause and CRC mortality compared with just below the cutoff.

Is there a place for sigmoidoscopy in colorectal cancer screening? A systematic review and critical appraisal of cost-effectiveness models

INTRODUCTION

Screening for colorectal cancer (CRC) is effective in reducing both incidence and mortality. Colonoscopy and stool tests are most frequently used for this purpose. Sigmoidoscopy is an alternative screening measure with a strong evidence base. Due to its distinct characteristics, it might be preferred by subgroups. The aim of this systematic review is to analyze the cost-effectiveness of sigmoidoscopy for CRC screening compared to other screening methods and to identify influencing parameters.

METHODS

A systematic literature search for the time frame 01/2010-01/2023 was conducted using the databases MEDLINE, Embase, EconLit, Web of Science, NHS EED, as well as the Cost-Effectiveness Registry. Full economic analyses examining sigmoidoscopy as a screening measure for the general population at average risk for CRC were included. Incremental cost-effectiveness ratios were calculated. All included studies were critically assessed based on a questionnaire for modelling studies.

RESULTS

Twenty-five studies are included in the review. Compared to no screening, sigmoidoscopy is a cost-effective screening strategy for CRC. When modelled as a single measure strategy, sigmoidoscopy is mostly dominated by colonoscopy or modern stool tests. When combined with annual stool testing, sigmoidoscopy in 5-year intervals is more effective and less costly than the respective strategies alone. The results of the studies are influenced by varying assumptions on adherence, costs, and test characteristics.

CONCLUSION

The combination of sigmoidoscopy and stool testing represents a cost-effective screening strategy that has not received much attention in current guidelines. Further research is needed that goes beyond a narrow focus on screening technology and models different, preference-based participation behavior in subgroups.

[Actitudes e imágenes sociales sobre el cribado de cáncer colorrectal. Una aproximación exploratoria mediante grupos de discusión.]

OBJECTIVE

The screening for colorectal cancer (CRC) through the fecal occult blood test (FOBT) has achieved high implementation in Spain, although participation rates are still not optimal. At the same time, available data show significant differences in participation both among autonomous communities and among different sociodemographic groups, which raises various equity issues. This study aimed to conduct an exploratory analysis from a qualitative perspective on the attitudes, perceptions, and social images that the target population for colorectal cancer screenings holded regarding them, as well as the barriers and areas for improvement identified through these.

METHODS

This study was designed using a qualitative research approach, through the conduct of four focus groups in May 2022, with a total of twenty-six participants (equal number of men and women) aged fifty to sixty-nine years. The participants were residents of the Community of Madrid, Catalonia, Andalusia, and the Basque Country (in both large and small cities), with varying educational levels and different previous experiences of participation in the CRC screening program.

RESULTS

Different conceptualizations of prevention were identified, but none that encompassed cancer (especially colorectal cancer) as an element to be incorporated into daily practices since its occurrence is primarily associated with chance. In addition to the lack of knowledge about CRC compared to other types of cancer (such as breast or prostate cancer), various attitudinal barriers to participation in the CRC screening program were perceived. These included the rejection of being part of the older age group (targeted by the test), fear of waiting for the results, lack of reliability, or the sense of being able to postpone the moment.

CONCLUSIONS

This study highlights the need for interventions aimed at promoting the attitude with which the invitation to participate is received and interpreted. It also emphasizes the importance of incorporating colon cancer into the dominant framework of concerns, raising awareness about the significance of early detection, and addressing potential sources of inequity. These interventions should address the broader conceptualization of the role of prevention observed among individuals with higher cultural capital and the greater normalization of screening programs found among women due to their previous experience with breast cancer screening.

Clinical evaluation of a multitarget fecal immunochemical test-sDNA test for colorectal cancer screening in a high-risk population: a prospective, multicenter clinical study

Colorectal cancer (CRC) is a major malignancy threatening the health of people in China and screening could be effective for preventing the occurrence and reducing the mortality of CRC. We conducted a multicenter, prospective clinical study which recruited 4,245 high-risk CRC individuals defined as having positive risk-adapted scores or fecal immunochemical test (FIT) results, to evaluate the clinical performance of the multitarget fecal immunochemical and stool DNA (FIT-sDNA) test for CRC screening. Each participant was asked to provide a stool sample prior to bowel preparation, and FIT-sDNA test and FIT were performed independently of colonoscopy. We found that 186 (4.4%) were confirmed to have CRC, and 375 (8.8%) had advanced precancerous neoplasia among the high CRC risk individuals. The sensitivity of detecting CRC for FIT-sDNA test was 91.9% (95% CI, 86.8-95.3), compared with 62.4% (95% CI, 54.9-69.3) for FIT (P < 0.001). The sensitivity for detecting advanced precancerous neoplasia was 63.5% (95% CI, 58.3-68.3) for FIT-sDNA test, compared with 30.9% (95% CI, 26.3-35.6) for FIT (P < 0.001). Multitarget FIT-sDNA test detected more colorectal advanced neoplasia than FIT. Overall, these findings indicated that in areas with limited colonoscopy resources, FIT-sDNA test could be a promising further risk triaging modality to select patients for colonoscopy in CRC screening.

Colorectal Cancer Screening in the Middle East: What, Why, Who, When, and How?

The incidence of colorectal cancer (CRC) in the Middle East is increasing, especially among those younger than 50 years. Risk factors including obesity, sedentary lifestyle, and dietary changes are associated with the epidemiologic shift and are a result of socioeconomic changes happening in the region. Worldwide, CRC screening is associated with decreased incidence and mortality of CRC, but screening uptake is still low in the Middle East because of cultural barriers and lack of awareness; in addition, most countries do not have national screening programs. Knowledge of CRC screening and participation rates vary among different countries, but overall they are low. Both primary and secondary prevention approaches are needed in the Middle East, and cost-effectiveness is important in choosing screening modalities. Although colonoscopy is considered the most robust screening method, stool-based testing may be an acceptable screening strategy in resource-limited settings, and focusing on high-risk individuals such as those with hereditary CRC might be the most cost-effective strategy. In addition to financial limitations in many countries in the Middle East, human displacement places an extra toll on cancer control strategies in the region.

Increasing the accuracy of colorectal cancer screening

INTRODUCTION

Colorectal cancer (CRC) is a major health issue, being responsible for nearly 10% of all cancer-related deaths. Since CRC is often an asymptomatic or paucisymptomatic disease until it reaches advanced stages, screening is crucial for the diagnosis of preneoplastic lesions or early CRC.

AREAS COVERED

The aim of this review is to summarize the literature evidence on currently available CRC screening tools, with their pros and cons, focusing on the level of accuracy reached by each test over time. We also provide an overview of novel technologies and scientific advances that are currently being investigated and that in the future may represent real game-changers in the field of CRC screening.

EXPERT OPINION

We suggest that best screening modalities are annual or biennial FIT and colonoscopy every 10 years. We believe that the introduction of artificial intelligence (AI)-tools in the CRC screening field could lead to a significant improvement of the screening efficacy in reducing CRC incidence and mortality in the future. More resources should be put into implementing CRC programmes and support research project to further increase accuracy of CRC screening tests and strategies.

Colon Cancer Screening Methods: 2023 Update

Colorectal cancer (CRC) is a significant cause of morbidity and mortality worldwide. National screening guidelines have been implemented to identify and remove precancerous polyps before they become cancer. Routine CRC screening is advised for people with average risk starting at age 45 because it is a common and preventable malignancy. Various screening modalities are currently in use, ranging from stool-based tests (fecal occult blood test (FOBT), fecal immunochemical test (FIT), and FIT-DNA test), radiologic tests (computed tomographic colonography (CTC), double contrast barium enema), and visual endoscopic examinations (flexible sigmoidoscopy (FS), colonoscopy, and colon capsule endoscopy (CCE)) with their varying sensitivity and specificity. Biomarkers also play a vital role in assessing the recurrence of CRC. This review offers a summary of the current screening options, including biomarkers available to detect CRC, highlighting the benefits and challenges encompassing each screening modality.

Effectiveness of Colorectal Cancer (CRC) Screening on All-Cause and CRC-Specific Mortality Reduction: A Systematic Review and Meta-Analysis

(1) Background: The aim of this study was to pool and compare all-cause and colorectal cancer (CRC) specific mortality reduction of CRC screening in randomized control trials (RCTs) and simulation models, and to determine factors that influence screening effectiveness. (2) Methods: PubMed, Embase, Web of Science and Cochrane library were searched for eligible studies. Multi-use simulation models or RCTs that compared the mortality of CRC screening with no screening in general population were included. CRC-specific and all-cause mortality rate ratios and 95% confidence intervals were calculated by a bivariate random model. (3) Results: 10 RCTs and 47 model studies were retrieved. The pooled CRC-specific mortality rate ratios in RCTs were 0.88 (0.80, 0.96) and 0.76 (0.68, 0.84) for guaiac-based fecal occult blood tests (gFOBT) and single flexible sigmoidoscopy (FS) screening, respectively. For the model studies, the rate ratios were 0.45 (0.39, 0.51) for biennial fecal immunochemical tests (FIT), 0.31 (0.28, 0.34) for biennial gFOBT, 0.61 (0.53, 0.72) for single FS, 0.27 (0.21, 0.35) for 10-yearly colonoscopy, and 0.35 (0.29, 0.42) for 5-yearly FS. The CRC-specific mortality reduction of gFOBT increased with higher adherence in both studies (RCT: 0.78 (0.68, 0.89) vs. 0.92 (0.87, 0.98), model: 0.30 (0.28, 0.33) vs. 0.92 (0.51, 1.63)). Model studies showed a 0.62-1.1% all-cause mortality reduction with single FS screening. (4) Conclusions: Based on RCTs and model studies, biennial FIT/gFOBT, single and 5-yearly FS, and 10-yearly colonoscopy screening significantly reduces CRC-specific mortality. The model estimates are much higher than in RCTs, because the simulated biennial gFOBT assumes higher adherence. The effectiveness of screening increases at younger screening initiation ages and higher adherences.

Trends of colorectal cancer screening methods: an analysis of Behavioral Risk Factor Surveillance System data from 2018-2020

CONTEXT

Colorectal cancer (CRC) has a high mortality rate and a large financial burden. Therefore, it is imperative to screen appropriately for this disease. By evaluating trends in different CRC screening methods and evaluating screening methods based on sex and race, improvements in screening can be made.

OBJECTIVES

By analyzing data from the Behavioral Risk Factor Surveillance System (BRFSS), our primary objective was to evaluate trends in CRC screening methods from 2018 through 2020. Our secondary objectives were to investigate deviations in screening rates by sex and race/ethnicity.

METHODS

A cross-sectional design was utilized to analyze trends in CRC screening methods utilizing data from the BRFSS for the years 2018 through 2020. Sex and race were also analyzed to evaluate for deviations in screening rates.

RESULTS

All race/ethnicity groups most often completed colonoscopies, with all but individuals identifying as Hispanic having higher than 56% completion rates. Individuals reporting as Hispanic received more blood stool tests than other races at 23.4%. Average CRC screening among all methods showed that 89.7% of individuals who reported as being White completed screening, with 91.3% of individuals reporting as Black, and 81.9% with race not listed, completed screening. Individuals identifying as Asian (74.4%), American Indian/Alaska Native (AI/AN [79.2%]) and Hispanic (78.1%) had lower rates of screening overall.

CONCLUSIONS

Our study found that trends in CRC screening were similar across years for individuals who reported as being White or Black. We also found that those identifying as Asian, AI/AN, Hispanic, and those whose identifying race was not listed deviated across years. These latter groups were also less likely to have received colonoscopies, the gold standard of screening. Because CRC is oftentimes a preventable disease, the importance of appropriate screening cannot be emphasized enough.

Molecular methods for colorectal cancer screening: Progress with next-generation sequencing evolution

Currently, colorectal cancer (CRC) represents the third most common malignancy and the second most deadly cancer worldwide, with a higher incidence in developed countries. Like other solid tumors, CRC is a heterogeneous genomic disease in which various alterations, such as point mutations, genomic rearrangements, gene fusions or chromosomal copy number alterations, can contribute to the disease development. However, because of its orderly natural history, easily accessible onset location and high lifetime incidence, CRC is ideally suited for preventive intervention, but the many screening efforts of the last decades have been compromised by performance limitations and low penetrance of the standard screening tools. The advent of next-generation sequencing (NGS) has both facilitated the identification of previously unrecognized CRC features such as its relationship with gut microbial pathogens and revolutionized the speed and throughput of cataloguing CRC-related genomic alterations. Hence, in this review, we summarized the several diagnostic tools used for CRC screening in the past and the present, focusing on recent NGS approaches and their revolutionary role in the identification of novel genomic CRC characteristics, the advancement of understanding the CRC carcinogenesis and the screening of clinically actionable targets for personalized medicine.

Modeling the Natural History and Screening Effects of Colorectal Cancer Using Both Adenoma and Serrated Neoplasia Pathways: The Development, Calibration, and Validation of a Discrete Event Simulation Model

Background. Existing colorectal cancer (CRC) screening models mostly focus on the adenoma pathway of CRC development, overlooking the serrated neoplasia pathway, which might result in overly optimistic screening predictions. In addition, Bayesian inference methods have not been widely used for model calibration. We aimed to develop a CRC screening model accounting for both pathways, calibrate it with approximate Bayesian computation (ABC) methods, and validate it with large CRC screening trials. Methods. A discrete event simulation (DES) of the CRC natural history (DECAS) was constructed using the adenoma and serrated pathways in R software. The model simulates CRC-related events in a specific birth cohort through various natural history states. Calibration took advantage of 74 prevalence data points from the German screening colonoscopy program of 5.2 million average-risk participants using an ABC method. CRC incidence outputs from DECAS were validated with the German national cancer registry data; screening effects were validated using 17-y data from the UK Flexible Sigmoidoscopy Screening sigmoidoscopy trial and a German screening colonoscopy cohort study. Results. The Bayesian calibration rendered 1,000 sets of posterior parameter samples. With the calibrated parameters, the observed age- and sex-specific CRC prevalences from the German registries were within the 95% DECAS-predicted intervals. Regarding screening effects, DECAS predicted a 41% (95% intervals 30%-51%) and 62% (95% intervals 55%-68%) reduction in 17-y cumulative CRC mortality for a single screening sigmoidoscopy and colonoscopy, respectively, falling within 95% confidence intervals reported in the 2 clinical studies used for validation. Conclusions. We presented DECAS, the first Bayesian-calibrated DES model for CRC natural history and screening, accounting for 2 CRC tumorigenesis pathways. The validated model can serve as a valid tool to evaluate the (cost-)effectiveness of CRC screening strategies.

Highlights

This article presents a new discrete event simulation model, DECAS, which models both adenoma-carcinoma and serrated neoplasia pathways for colorectal cancer (CRC) development and CRC screening effects.DECAS is calibrated based on a Bayesian inference method using the data from German screening colonoscopy program, which consists of more than 5 million first-time average-risk participants aged 55 years and older in 2003 to 2014.DECAS is flexible for evaluating various CRC screening strategies and can differentiate screening effects in different parts of the colon.DECAS is validated with large screening sigmoidoscopy and colonoscopy clinical study data and can be further used to evaluate the (cost-)effectiveness of German colorectal cancer screening strategies.

Heterogeneous Preferences for Colorectal Cancer Screening in Germany: Results of a Discrete Choice Experiment

OBJECTIVES

Colorectal cancer (CRC) screening tests differ in benefits, harms, and processes, making individual informed decisions preference based. The objective was to analyze the preferences of insurees in Germany for characteristics of CRC screening modalities.

METHODS

A generic discrete choice experiment with 2-alternative choice sets and 6 attributes (CRC mortality, CRC incidence, complications, preparation, need for transportation, and follow-up; 3 levels each) depicting characteristics of fecal testing, sigmoidoscopy, and colonoscopy was generated. Participants completed 8 choice tasks. Internal validity was tested using a within-set dominated pair. Between June and October 2020, written questionnaires were sent to a stratified random sample (n = 5000) of 50-, 55-, and 60-year-old insurees of the AOK (Allgemeine Ortskrankenkasse) Lower Saxony, who had previously received an invitation to participate in the organized screening program including evidence-based information. Preferences were analyzed using conditional logit, mixed logit, and latent-class model.

RESULTS

From 1282 questionnaires received (26% [1282 of 4945]), 1142 were included in the analysis. Approximately 42% of the respondents chose the dominated alternative in the internal validity test. Three heterogeneous preference classes were identified. Most important attributes were preparation (class 1; n = 505, 44%), CRC mortality (class 2; n = 347, 30%), and CRC incidence (class 3; n = 290, 25%). Contrary to a priori expectations, a higher effort was preferred for bowel cleansing (class 1) and accompaniment home (classes 1 and 2).

CONCLUSION

Internal validity issues of choice data need further research and warrant attention in future discrete choice experiment surveys. The observed preference heterogeneity suggests different informational needs, although the underlying reasons remained unclear.

Adenoma and Sessile Serrated Lesion Detection Rates at Screening Colonoscopy for Ages 45-49 Years vs Older Ages Since the Introduction of New Colorectal Cancer Screening Guidelines

BACKGROUND AND AIMS

All major U.S. guidelines now endorse average-risk colorectal cancer (CRC) screening at 45-49 years of age. Concerns exist that endoscopic capacity may be strained, that low-risk persons may self-select for screening, and that calculations of the adenoma detection rate may be diluted. We analyzed age-specific screening colonoscopy volumes and lesion detection rates before vs after the endorsement of CRC screening at 45-49 years of age.

METHODS

We compared colonoscopy volumes and lesion detection rates in our healthcare system during period 1 (October 2017 to December 2018), before the first change in guidelines, vs period 2 (January 2019 to August 2021), the era of new guidelines.

RESULTS

The proportion of first-time screening colonoscopies performed in 45- to 49-year-olds increased from 3.5% to 11.6% (relative risk, 3.36; 95% CI, 2.45-4.61). The period 2 detection rates for adenoma, advanced adenoma, sessile serrated lesion, advanced sessile serrated lesion, adenomas per colonoscopy, and lesions per colonoscopy were very similar for 45- to 49-year-olds (34.3%, 6.3%, 8.6%, 2.9%, 0.58, and 0.69, respectively) and 50- to 54-year-olds (38.2%, 5.8%, 9.4%, 3.0%, 0.63, and 0.76, respectively) at first-time screening, and for 60- to 64-year-olds at rescreening (33.4%, 6.1%, 7.2%, 2.3%, 0.61, and 0.70, respectively). All detection rates, adenomas per colonoscopy, and lesions per colonoscopy increased from period 1 to period 2 (eg, overall adenoma detection rate 35.1% vs 42.6%; P < .0001), without any decreases among 45- to 49-year-olds.

CONCLUSIONS

In our healthcare system, a lower CRC screening initiation age has modestly affected colonoscopy volume by age without compromising screening yield. Lesion detection rates, including for advanced adenomas, in average-risk 45- to 49-year-olds approximate those in 50- to 54-year-olds at first-time screening and 60- to 64-year-olds at rescreening. National monitoring is needed to assess fully the impact of lowering the CRC screening initiation age.

Short-chain fatty acid concentrations in the incidence and risk-stratification of colorectal cancer: a systematic review and meta-analysis

BACKGROUND

The beneficial role of gut microbiota and bacterial metabolites, including short-chain fatty acids (SCFAs), is well recognized, although the available literature around their role in colorectal cancer (CRC) has been inconsistent.

METHODS

We performed a systematic review and meta-analysis to examine the associations of fecal SCFA concentrations to the incidence and risk of CRC. Data extraction through Medline, Embase, and Web of Science was carried out from database conception to June 29, 2022. Predefined inclusion/exclusion criteria led to the selection of 17 case-control and six cross-sectional studies for quality assessment and analyses. Studies were categorized for CRC risk or incidence, and RevMan 5.4 was used to perform the meta-analyses. Standardized mean differences (SMD) with 95% confidence intervals (CI) were calculated using a random-effects model. Studies lacking quantitation were included in qualitative analyses.

RESULTS

Combined analysis of acetic, propionic, and butyric acid revealed significantly lower concentrations of these SCFAs in individuals with a high-risk of CRC (SMD = 2.02, 95% CI 0.31 to 3.74, P = 0.02). Additionally, CRC incidence was higher in individuals with lower levels of SCFAs (SMD = 0.45, 95% CI 0.19 to 0.72, P = 0.0009), compared to healthy individuals. Qualitative analyses identified 70.4% of studies reporting significantly lower concentrations of fecal acetic, propionic, butyric acid, or total SCFAs in those at higher risk of CRC, while 66.7% reported significantly lower concentrations of fecal acetic and butyric acid in CRC patients compared to healthy controls.

CONCLUSIONS

Overall, lower fecal concentrations of the three major SCFAs are associated with higher risk of CRC and incidence of CRC.

[PAPPS Expert Groups. Cancer prevention recommendations: Update 2022]

Cancer is a major cause of morbidity and mortality. Tobacco use, unhealthy diet, and physical inactivity are some of the lifestyle risk factors that have led to an increase in cancer. This article updates the evidence and includes recommendations for prevention strategies for each of the cancers with the highest incidence. These are based on the reduction of risk factors (primary prevention) and early diagnosis of cancer through screening and early detection of signs and symptoms, in medium-risk and high-risk populations. This update of the 2022 PAPPS has taken into account the vision of the National Health System Cancer Strategy, an update approved by the Interterritorial Council of the National Health System on January 2021 and the European Strategy (Europe's Beating Cancer Plan) presented on 4 February 2021.

Attributes in stated preference elicitation studies on colorectal cancer screening and their relative importance for decision-making among screenees: a systematic review

INTRODUCTION

The SIGMO study (Sigmoidoscopy as an evidence-based colorectal cancer screening test - a possible option?) examines screening eligible populations' preferences for colorectal cancer (CRC) screening in Germany using a discrete choice experiment (DCE). Attribute identification and selection are essential for the construction of choice tasks and should be evidence-based. As a part of the SIGMO study this systematic review provides an overview of attributes included in studies eliciting stated preferences for CRC screening tests and their relative importance for decision-making.

METHODS

Systematic search (November 2021) for English-language studies published since January 2000 in PubMed, Embase, Web of Science, Biomedical Reference Collection: Corporate Edition, LIVIVO and PsycINFO. DCEs and conjoint analysis ranking or rating tasks on screening eligible populations' preferences for stool testing, sigmoidoscopy, and/or colonoscopy were included. Attributes were extracted and their relative importance was calculated and ranked. Risk of bias (RoB) of included studies was assessed using a modified GRADE (Grading of Recommendations Assessment, Development and Evaluation) approach. Study selection and RoB rating were carried out independently by two reviewers. Data were extracted by one reviewer and checked by another one.

RESULTS

A total of 23 publications on 22 studies were included. Overall RoB was rated as serious/critical for 21 studies and as moderate for 2 studies. Main reasons for high RoB were non-random sampling, low response rates, lack of non-responder analyses, and, to a lesser extent, weaknesses in the measurement instrument and data analysis. Extracted attributes (n = 120) referred to procedure-related characteristics (n = 42; 35%), structural characteristics of health care (n = 24; 20%), test characteristics (n = 23; 19%), harms (n = 16; 13%), benefits (n = 13; 11%), and level of evidence (n = 2; 2%). Most important attributes were reduction in CRC mortality (and incidence) (n = 7), test sensitivity (n = 7), out-of-pocket costs (n = 4), procedure (n = 3), and frequency (n = 2).

CONCLUSIONS

Health preference studies on CRC were found to have a high RoB. The composition of choice tasks revealed a lack of attributes on patient-important outcomes (like incidence reduction), while attributes not considered relevant for individual screening decisions (like sensitivity) were frequently used. Future studies eliciting stated preferences in cancer screening should apply the principles of informed decision-making in attribute identification and selection.

Expression Levels and Clinical Significance of Serum miR-497, CEA, CA24-2, and HBsAg in Patients with Colorectal Cancer

The objective of the current study was to look at the levels of blood micro ribonucleic acid- (miR-) 497, carcinoembryonic antigen (CEA), carbohydrate antigen (CA) 24-2, and hepatitis B surface antigen (HBsAg) in patients with colorectal cancer (CRC), as well as the clinical importance of these markers in CRC patients. The serum levels of miR-497, CEA, CA24-2, and HBsAg were compared between 60 patients with CRC (observation group) and another 60 patients with colorectal polyps (control group). The 4 indicators in patients with lymph node metastasis and liver metastasis were compared. The diagnostic effects of 4 detection methods and the combined detection were analyzed, and the influence of 4 indicators on the 5-year cumulative survival rate of patients was discussed. The results showed that the serum levels of miR-497 and HBsAg were lower, and the levels of CEA and CA24-2 were higher in the observation group (P < 0.05). The combined detection had the best diagnostic effect, and CEA alone had the best prediction effect. The serum level of miR-497 was significantly lower in patients with lymphatic metastasis, with the significantly higher levels of CEA and CA24-2 (P < 0.05). The HBsAg level of patients with liver metastases was greatly lower than that of patients without liver metastases (P < 0.05). The 5-year cumulative survival rate of patients with high levels of CEA and CA24-2 was significantly lower than that of patients with low level of CEA. The 5-year cumulative survival rate was lower in patients with low level of HBsAg, but the difference was small. The 5-year cumulative survival rate of patients with elevated serum miR-497 was observably lower. In conclusion, combined detection could diagnose CRC more accurately. Serum miR-497, CEA, and CA24-2 were important in the diagnosis of lymph node metastasis of CRC. HBsAg did a better job of predicting liver metastases in CRC patients. High level of CEA significantly reduced the cumulative survival rate of CRC patients and could predict the long-term survival rate of patients. Serum levels of miR-497, CEA, CA24-2, and HBsAg played a positive role in the diagnosis and evaluation of CRC and could identify lymph node and liver metastases, having a high clinical guidance value.

Coupé VM. A progressive three-state model to estimate time to cancer: a likelihood-based approach

Background

To optimize colorectal cancer (CRC) screening and surveillance, information regarding the time-dependent risk of advanced adenomas (AA) to develop into CRC is crucial. However, since AA are removed after diagnosis, the time from AA to CRC cannot be observed in an ethically acceptable manner. We propose a statistical method to indirectly infer this time in a progressive three-state disease model using surveillance data.

Methods

Sixteen models were specified, with and without covariates. Parameters of the parametric time-to-event distributions from the adenoma-free state (AF) to AA and from AA to CRC were estimated simultaneously, by maximizing the likelihood function. Model performance was assessed via simulation. The methodology was applied to a random sample of 878 individuals from a Norwegian adenoma cohort.

Results

Estimates of the parameters of the time distributions are consistent and the 95% confidence intervals (CIs) have good coverage. For the Norwegian sample (AF: 78%, AA: 20%, CRC: 2%), a Weibull model for both transition times was selected as the final model based on information criteria. The mean time among those who have made the transition to CRC since AA onset within 50 years was estimated to be 4.80 years (95% CI: 0; 7.61). The 5-year and 10-year cumulative incidence of CRC from AA was 13.8% (95% CI: 7.8%;23.8%) and 15.4% (95% CI: 8.2%;34.0%), respectively.

Conclusions

The time-dependent risk from AA to CRC is crucial to explain differences in the outcomes of microsimulation models used for the optimization of CRC prevention. Our method allows for improving models by the inclusion of data-driven time distributions.

Supplementary Information

The online version contains supplementary material available at (10.1186/s12874-022-01645-2).

Colorectal cancer mortality after randomized implementation of FIT-based screening - a nationwide cohort study

Objective

Evidence of reduction in colorectal cancer (CRC) mortality following CRC screening based on the faecal immunochemical test (FIT) is insufficient. This study aimed to analyse if CRC mortality was reduced after implementing FIT-based screening.

Setting

The Danish national CRC screening programme.

Methods

This nationwide cohort study included residents aged 50–71 years invited to the prevalence round of the screening programme. Invitation order was decided by randomising on birth month; the first two birth months to be invited were classified as invited and the five last were classified as not-yet-invited and given a pseudo invitation data. Follow-up was from (pseudo)invitation date until 31 December 2017, emigration or death. Relative risk (RR) of CRC death was calculated with 95% confidence intervals (CIs).

Results

A total of 897,812 residents were included (29% invited and 71% not-yet-invited). The median follow-up was 3.3 years. The RR of CRC death at end of follow-up was 0.83 (95% CI 0.66; 1.03) among those invited to screening compared with those not yet invited. For men aged 60–71 years, this RR was 0.68 (95% CI 0.49; 0.94). For those participating in screening compared with a similar group of not-yet-invited residents, the RR was 0.71 (95% CI 0.46–1.08). For male participants aged 60–71 years, this RR was 0.49 (95% CI 0.27−0.89). For women and men aged 50–59 years, RRs were small and statistically non-significant.

Conclusion

This nationwide study showed that even within a median follow-up of only 3.3 years, implementing FIT-based CRC screening reduced CRC mortality among older men.

Short and long-term psychosocial consequences of participating in a colorectal cancer screening programme: a matched longitudinal study

OBJECTIVES

To investigate the psychosocial consequences of receiving a false-positive (no abnormalities) result or being diagnosed with polyps compared with receiving a negative result in a colorectal cancer (CRC) screening programme.

DESIGN AND SETTING

This was a longitudinal study nested in the roll-out of the Danish CRC screening programme that targets all individuals aged 50-74 years.

PARTICIPANTS

In the inclusion period (April-September 2017), all positive screenees (n=1854) were consecutively enrolled and matched 2:1:1 on sex, age (±2 years), municipality and screening date with negative screenees (n=933) and individuals not yet invited to screening (n=933).Questionnaires were sent by mail to all eligible participants in Region Zealand, Denmark, after the screening result, 2 months and 12 months after the final result.Positive screenees who did not receive the follow-up procedure were excluded.

MAIN OUTCOME MEASURES

The primary outcomes were psychosocial consequences. Outcomes were measured with the CRC screening-specific questionnaire Consequences of screening in CRC with 11 outcomes after the screening result and with 21 outcomes at the two later assessments.

RESULTS

After receiving the screening result, individuals with no abnormalities, low-risk and medium-risk and high-risk polyps scored significantly worse on 8 of 11 outcomes compared with the negative screenee group. At the 12-month follow-up, the differences were still significant in 8 of 21 outcomes (no abnormalities), 4 of 21 outcomes (low-risk polyps) and 10 of 21 outcomes (medium-risk and high-risk polyps). The negative screenee group and the group not yet invited to screening differed psychosocially on 5 of 11 outcomes after the screening result, but on none of the 21 outcomes at the 2 months and 12 months follow-up.

CONCLUSIONS

The study showed that there are both short-term and long-term psychosocial consequences associated with receiving a no abnormalities result or being diagnosed with polyps. The consequences were worst for individuals diagnosed with medium-risk and high-risk polyps.

Optimal Strategies for Colorectal Cancer Screening

Colorectal cancer (CRC) imposes significant morbidity and mortality, yet it is also largely preventable with evidence-based screening strategies. In May 2021, the US Preventive Services Task Force updated guidance, recommending screening begin at age 45 for average-risk individuals to reduce CRC incidence and mortality in the United States (US). The Task Force recommends screening with one of several screening strategies: high-sensitivity guaiac fecal occult blood test (HSgFOBT), fecal immunochemical test (FIT), multi-target stool DNA (mt-sDNA) test, computed tomographic (CT) colonography (virtual colonoscopy), flexible sigmoidoscopy, flexible sigmoidoscopy with FIT, or traditional colonoscopy. In addition to these recommended options, there are several emerging and novel CRC screening modalities that are not yet approved for first-line screening in average-risk individuals. These include blood-based screening or “liquid biopsy,” colon capsule endoscopy, urinary metabolomics, and stool-based microbiome testing for the detection of colorectal polyps and/or CRC. In order to maximize CRC screening uptake in the US, patients and providers should engage in informed decision-making about the benefits and limitations of recommended screening options to determine the most appropriate screening test. Factors to consider include the invasiveness of the test, test performance, screening interval, accessibility, and cost. In addition, health systems should have a programmatic approach to CRC screening, which may include evidence-based strategies such as patient education, provider education, mailed screening outreach, and/or patient navigation, to maximize screening participation.

Counting Advanced Precancerous Lesions as True Positives When Determining Colorectal Cancer Screening Test Specificity

The landmark Centers for Medicare & Medicaid Services (CMS) decision memo on blood-based biomarkers to screen for colorectal cancer (CRC) sets thresholds of 74% or higher for sensitivity and 90% or higher for specificity for CRC. This approach does not consider detection of advanced precancerous lesions as true positives. We contrasted the impact of counting advanced precancerous lesions as true vs false positives and projected CRC outcomes under contrasting tests in a validated model. A test with the threshold performance set by CMS decreased CRC incidence by 30% and CRC mortality by 48% in individuals aged 45 years. If this test also detected advanced precancerous lesions with 30% sensitivity, CRC incidence decreased by 45% and mortality by 58%, but the CRC specificity of the test of only 88% would not satisfy the CMS threshold. CMS should reconsider its definition of threshold specificity for CRC screening biomarkers. Future coverage determinations on biomarkers to screen for cancer should consider detection of relevant precursor lesions and projected outcomes.

Long-term colorectal cancer incidence and mortality after adenoma removal in women and men

BACKGROUND

Women and men with colorectal adenomas are at increased risk of colorectal cancer and colonoscopic surveillance is recommended. However, the long-term cancer risk remains unknown.

AIMS

To investigate colorectal cancer incidence and mortality after adenoma removal in women and men METHODS: We identified all individuals who had adenomas removed in Norway from 1993 to 2007, with follow-up through 2018. We calculated standardized incidence ratios (SIR) and incidence-based mortality ratios (SMR) with 95% confidence intervals (CI) for colorectal cancer in women and men using the female and male population for comparison. We defined high-risk adenomas as ≥2 adenomas, villous component, or high-grade dysplasia.

RESULTS

The cohort comprised 40 293 individuals. During median follow-up of 13.0 years, 1079 women (5.5%) and 866 men (4.2%) developed colorectal cancer; 328 women (1.7%) and 275 men (1.3%) died of colorectal cancer. Colorectal cancer incidence was more increased in women (SIR 1.64, 95% CI 1.54-1.74) than in men (SIR 1.12, 95% CI 1.05-1.19). Colorectal cancer mortality was increased in women (SMR 1.13, 95% CI 1.02-1.26) and reduced in men (SMR 0.79, 95% CI 0.71-0.89). Women with high-risk adenomas had an increased risk of colorectal cancer death (SMR 1.37, 95% CI 1.19-1.57); women with low-risk adenomas (SMR 0.90, 95% CI 0.76-1.07) and men with high-risk adenomas had a similar risk (SMR 0.89, 95% CI 0.76-1.04), while men with low-risk adenomas had reduced risk (SMR 0.70, 95% CI 0.59-0.84).

CONCLUSIONS

After adenoma removal, women had an increased risk of colorectal cancer death, while men had reduced risk, compared to the general female and male populations. Sex-specific surveillance recommendations after adenoma removal should be considered.

Additional offer of sigmoidoscopy in colorectal cancer screening in Germany: rationale and protocol of the decision-analytic modelling approach in the SIGMO study

INTRODUCTION

In Germany, statutory insured persons are entitled to a stool test (faecal immunochemical test (FIT)) or colonoscopy for colorectal cancer (CRC) screening, depending on age and sex, yet participation rates are rather low. Sigmoidoscopy is a currently not available screening measure that has a strong evidence base for incidence and mortality reduction. Due to its distinct characteristics, it might be preferred by some, who now reject colonoscopy. The objective of this study is to estimate the economic consequences of the additional offer of sigmoidoscopy for CRC screening in Germany compared with the present screening practice while considering the preferences of the general population.

METHODS AND ANALYSIS

A decision-analytic modelling approach will be developed that compares the present CRC screening programme in Germany (FIT, colonoscopy) with a programme extended by sigmoidoscopy from a societal perspective. A decision tree and Markov model will be combined to assess both short-term and long-term effects, such as CRC and adenoma detection rates, the number of CRC cases, CRC mortality as well as complications. The incremental cost per quality-adjusted life year gained for each alternative will be calculated. The model will incorporate the general population's preferences based on a discrete choice experiment. Further, input parameters will be taken from the literature, the German cancer registry and health insurance claims data.

ETHICS AND DISSEMINATION

Ethical approval for the study was obtained from the Ethics Committee of Hannover Medical School (ID: 8671_BO_K_2019). The findings of the study will be published in peer-reviewed journals and presented at national and/or international conferences.

TRIAL REGISTRATION NUMBER

DRKS00019010.

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.

Attributes Characterizing Colorectal Cancer Screening Tests That Influence Preferences of Individuals Eligible for Screening in Germany: A Qualitative Study

PURPOSE

This qualitative study is part of the SIGMO study, which evaluates general populations' preferences for colorectal cancer (CRC) screening in Germany using a discrete choice experiment. Attribute identification and selection are essential in the construction of choice tasks and should be evidence-based ensuring that attributes are relevant to potential beneficiaries and contribute to overall utility. Therefore, this qualitative study aims to identify relevant attributes characterizing CRC screening tests from the perspective of those eligible for screening in Germany.

PATIENTS AND METHODS

Individuals aged 50 to 60 were purposively selected. A questioning route was developed and piloted. Four focus groups (FG) (n=20) were conducted (November 2019) with two moderators and one observer each. FGs were audio recorded, transcribed, and analyzed using qualitative content analysis. Attributes were deductively assigned based on a priori identified attribute categories, and inductively derived.

RESULTS

Across FGs, 24 attributes (n=293 codes) were discussed, five of which (sedation, inability to work, transportation home, predictive values, waiting time for screening colonoscopy) were inductively derived (n=76 codes). Four attributes identified a priori were not addressed in any FG. The most frequently discussed attribute category was procedural characteristics, followed by measures of screening test validity, benefits, harms, and structural characteristics of health care. The most commonly addressed attributes were preprocedural bowel cleansing, kind of procedure, and predictive values.

CONCLUSION

Newly identified attributes characterizing CRC screening tests from an individual's perspective, and a priori identified attributes not addressed by any FG stress the added value of qualitative research and thereby the importance of applying a mix of methods in identifying and selecting attributes for the construction of choice tasks. This study meets the requirements for a transparent and detailed presentation of the qualitative methods used in this process, which has rarely been the case before.