Impact on colorectal cancer mortality of screening programmes based on the faecal immunochemical test

Risk factors for advanced colorectal neoplasia and colorectal cancer detected at surveillance: a nationwide study in the modern era

AIM

Recommendations for surveillance after colonoscopy are based on risk factors for metachronous advanced colorectal neoplasia (AN) and colorectal cancer (CRC). The value of these risk factors remains unclear in populations enriched by individuals with a positive faecal immunochemical test and were investigated in a modern setting.

METHODS AND RESULTS

This population-based cohort study included all individuals in the Netherlands of ≥55 years old with a first adenoma diagnosis in 2015. A total of 22,471 patients were included. Data were retrieved from the Dutch Nationwide Pathology Databank (Palga). Primary outcomes were metachronous AN and CRC. Patient and polyp characteristics were evaluated by multivariable Cox regression analyses. During follow-up, 2416 (10.8%) patients were diagnosed with AN, of which 557 (2.5% from the total population) were CRC. Adenomas with high-grade dysplasia (hazard ratio [HR] 1.60, 95% confidence interval [CI] 1.40-1.83), villous histology (HR 1.91, 95% CI 1.59-2.28), size ≥10 mm (HR 1.12, 95% CI 1.02-1.23), proximal location (HR 1.12, 95% CI 1.02-1.23), two or more adenomas (HR 1.28, 95% CI 1.16-1.41), and serrated polyps ≥10 mm (HR 1.67, 95% CI 1.42-1.97) were independent risk factors for metachronous AN. In contrast, only adenomas with high-grade dysplasia (HR 2.49, 95% CI 1.92-3.24) were an independent risk factor for metachronous CRC.

CONCLUSIONS

Risk factors for metachronous AN and CRC were identified for populations with access to a faecal immunochemical test (FIT)-based screening programme. If only risk factors for metachronous CRC are considered, a reduction in criteria for surveillance seems reasonable.

Discovery and validation of colorectal cancer tissue-specific methylation markers: a dual-center retrospective cohort study

BACKGROUND AND PURPOSE

Early detection, diagnosis, and treatment of colorectal cancer and its precancerous lesions can significantly improve patients' survival rates. The purpose of this research is to identify methylation markers specific to colorectal cancer tissues and validate their diagnostic capability in colorectal cancer and precancerous changes by measuring the level of DNA methylation in stool samples.

METHOD

We analyzed samples from six cancer tissues and adjacent normal tissues and fecal samples from 758 participants, including 62 patients with interfering diseases. Bioinformatics databases were used to screen for candidate biomarkers for CRC, and quantitative methylation-specific PCR methods were applied for identification. The methylation levels of the candidate biomarkers in fecal and tissue samples were measured. Logistic regression and random forest models were built and validated using fecal sample data from one of the centers, and the independent or combined diagnostic value of the candidate biomarkers in fecal samples for CRC and precancerous lesions was analyzed. Finally, the diagnostic capability and stability of the model were validated at another medical center.

RESULTS

This study identified two colorectal cancer CpG sites with tissue specificity. These two biomarkers have certain diagnostic power when used individually, but their diagnostic value for colorectal cancer and colorectal adenoma is more significant when they are used in combination.

CONCLUSION

The results indicate that a DNA methylation biomarker combined diagnostic model based on two CpG sites, cg13096260 and cg12587766, has the potential for screening and diagnosing precancerous lesions and colorectal cancer. Additionally, compared to traditional diagnostic models, machine learning algorithms perform better but may yield more false-positive results, necessitating further investigation.

Colorectal cancer mortality trend analysis in Montenegro from 1990 to 2018

Colorectal cancer (CRC) is the second leading cause of cancer-related death in Europe. This study aimed to investigate CRC mortality trends in Montenegro from 1990 to 2018 and critically review the impact of preventive activities on cancer suppression in this country. We used the national CRC mortality data categorized by sex and age. Mortality rates were age-standardized according to the World Standard Population. The trends were described using regression techniques. In the period from 1990 to 2018, there was a significant increase in CRC mortality (P < .05). The death rates and the number of deaths from CRC were constantly increasing for both the overall level and gender, with the mean annual percentage change for the rates respectively average annual percent change (95% confidence interval-CI): 2.6% (1.9-3.2), 2.6% (1.8-3.5); 2.3% (1.3-3.3), and for the number of cases, respectively: 4.2% (3.5-4.9), 4.3% (3.3-5.3), 4.3% (3.2-5.5). The most affected age groups were 65 to 74 years (33%), followed by those aged 75 to 84 years (25%) and the age group 55 to 64 (22%). In Montenegro, CRC mortality trends are increasing among both men and women over the age of 45. Additional research on the risk factors and mechanisms that contribute to the unfavorable trends in CRC mortality in Montenegro is necessary.

Trends in colorectal cancer surgical resection rates during the screening era: a retrospective study in Italy

BACKGROUND

Faecal immunochemical test (FIT)-based screening is effective in reducing colorectal cancer (CRC) incidence, but its sensitivity for proximal lesions remains low.

OBJECTIVES

We compared age-adjusted CRC surgical resection rates across anatomic sites (proximal colon, distal colon, rectum), age groups and sex over 20 years in a large Italian population. We particularly focused on changes in trends following FIT-screening implementation in the target population (50-69 years).

DESIGN

This retrospective study analysed data from the Veneto Region's administrative Hospital Discharge Dataset, involving over 54 000 patients aged 40-89 (43.4% female) who underwent CRC surgery between 2002 and 2021.

RESULTS

Overall, surgery rates increased until 2007 (annual percentage changes: 2.5% in males, 2.9% in females) and then declined (-4.2% in males, -3.4% in females). This decline was steeper for distal and rectal cancers compared with proximal cancer, suggesting a shift towards more right-sided CRC surgery.In males, the prescreening increase in proximal surgery was reversed after screening implementation (slope change: -6%) while the prescreening decline accelerated for distal (-4%) and rectal (-3%) surgeries. In females, stable prescreening trends shifted downward for all sites (-5% for proximal, -8% for distal and -7% for rectal surgery). However, the change in trends between prescreening and postscreening periods was not different across anatomic sites for either sex (all slope change differences in pairwise comparisons were not statistically significant).

CONCLUSION

The shift towards proximal surgery may not be entirely due to the FIT's low sensitivity but may reflect an underlying upward trend in proximal cancers independent of screening.

Barriers and proposed solutions to at-home colorectal cancer screening tests in medically underserved health centers across three US regions to inform a randomized trial

INTRODUCTION

At-home colorectal cancer (CRC) screening is an effective way to reduce CRC mortality, but screening rates in medically underserved groups are low. To plan the implementation of a pragmatic randomized trial comparing two population-based outreach approaches, we conducted qualitative research on current processes and barriers to at-home CRC screening in 10 community health centers (CHCs) that serve medically underserved groups, four each in Massachusetts and California, and two tribal facilities in South Dakota.

METHODS

We conducted 53 semi-structured interviews with clinical and administrative staff at the participating CHCs. Participants were asked about CRC screening processes, categorized into eight domains: patient identification, outreach, risk assessment, fecal immunochemical test (FIT) workflows, FIT-DNA (i.e., Cologuard) workflows, referral for a follow-up colonoscopy, patient navigation, and educational materials. Transcripts were analyzed using a Rapid Qualitative Analysis approach. A matrix was used to organize and summarize the data into four sub-themes: current process, barriers, facilitators, and solutions to adapt materials for the intervention.

RESULTS

Each site's process for stool-based CRC screening varied slightly. Interviewees identified the importance of offering educational materials in English and Spanish, using text messages to remind patients to return kits, adapting materials to address health literacy needs so patients can access instructions in writing, pictures, or video, creating mailed workflows integrated with a tracking system, and offering patient navigation to colonoscopy for patients with an abnormal result.

CONCLUSION

Proposed solutions across the three regions will inform a multilevel intervention in a pragmatic trial to increase CRC screening uptake in CHCs.

SIED-GISCOR recommendations for colonoscopy in screening programs: Part I - Diagnostic

The implementation of FIT programs reduces incidence and mortality from CRC in the screened subjects. The ultimate efficacy for CRC morbidity and mortality prevention in a FIT program depends on the colonoscopy in FIT+ subjects that has the task of detecting and removing these advanced lesions. Recently, there has been growing evidence on factors that influence the quality of colonoscopy specifically withing organized FIT programs, prompting to dedicated interventions in order to maximize the benefit/harm ratio of post-FIT colonoscopy. This document focuses on the diagnostic phase of colonoscopy, providing indications on how to standardise colonoscopy in FIT+ subjects, regarding timing of examination, management of antithrombotic therapy, bowel preparation, competence and sedation.

Unveiling Colorectal Cancer Biomarkers: Harnessing Biosensor Technology for Volatile Organic Compound Detection

Conventional screening options for colorectal cancer (CRC) detection are mainly direct visualization and invasive methods including colonoscopy and flexible sigmoidoscopy, which must be performed in a clinical setting and may be linked to adverse effects for some patients. Non-invasive CRC diagnostic tests such as computed tomography colonography and stool tests are either too costly or less reliable than invasive ones. On the other hand, volatile organic compounds (VOCs) are potentially ideal non-invasive biomarkers for CRC detection and monitoring. The present review is a comprehensive presentation of the current state-of-the-art VOC-based CRC diagnostics, with a specific focus on recent advancements in biosensor design and application. Among them, breath-based chromatography pattern analysis and sampling techniques are overviewed, along with nanoparticle-based optical and electrochemical biosensor approaches. Limitations of the currently available technologies are also discussed with an outlook for improvement in combination with big data analytics and advanced instrumentation, as well as expanding the scope and specificity of CRC-related volatile biomarkers.

Detection of colorectal cancer and advanced neoplasia during first surveillance interval after detection of adenomas in fecal immunochemical test cancer screening: a nationwide study

BACKGROUND

Adenoma surveillance guidelines are based on non-fecal immunochemical test (FIT)-based screening settings. However, colorectal cancer (CRC) risk may be different in FIT-positive screening populations. We evaluated the CRC and advanced adenoma risk within the recommended surveillance periods in the Danish FIT-based CRC screening program for participants with intermediate or high risk adenomas according to 2010 European guidelines. Furthermore, we estimated CRC risk for those who were not recommended surveillance according to European Society of Gastrointestinal Endoscopy (ESGE) 2020 guidelines.

METHODS

Using nationwide health registries, we identified 17 936 FIT-screening participants from 2014-2017 with adenomas undergoing surveillance (high risk 1 year, intermediate risk 3 years). Participants with a follow-up examination were included (N = 10 068). Relative risk (RR) of CRC and advance adenoma was compared between intermediate and high risk groups and between intermediates who were recommended surveillance (S) or no surveillance (NS) according to 2020 ESGE guidelines.

RESULTS

During surveillance, CRC occurred in 0.59% of the high risk group and 1.11% of the intermediate risk group (RR 0.53 [95%CI 0.34-0.84]). The high risk group had a 24% increased risk of advanced adenoma. CRC occurred in 1.69% of the intermediateNS group and 0.87% of the intermediateS group (RR 1.94 [95%CI 1.18-3.21]), and RR for advanced adenoma was 1.19 (95%CI 1.03-1.37).

CONCLUSION

CRC detection was lower among participants rated at higher risk at initial CRC screening. Findings at first screen-derived colonoscopy might not be as good a predictor of CRC risk in a FIT-positive screening population.

Precision Colorectal Cancer Fecal Immunological Test Screening With Fecal-Hemoglobin-Concentration-Guided Interscreening Intervals

Importance

Given a gradient relationship between fecal hemoglobin (f-Hb) concentration and colorectal neoplasia demonstrated previously, using f-Hb-guided interscreening interval has increasingly gained attention in population-based fecal immunological test (FIT), but it is very rare to address how to implement such a precision strategy and whether it can economize the use of FIT and colonoscopy.

Objective

To demonstrate the applicability of personalized colorectal cancer (CRC) screening with f-Hb-guided screening intervals to reduce the number of FITs and colonoscopy with as equivalent efficacy as universal biennial screening.

Design, Setting, and Participants

A retrospective cohort study for developing f-Hb-guided precision interscreening interval was conducted using data on a Taiwanese biennial nationwide FIT screening program that enrolled more than 3 million participants aged 50 to 74 years between 2004 and 2014. The cohort was followed up over time until 2019 to ascertain colorectal neoplasia and causes of death. A comparative study was further designed to compare the use of FIT and colonoscopy between the personalized f-Hb-guided group and the universal biennial screening group given the equivalent efficacy of reducing CRC-related outcomes.

Main Outcomes and Measurements

A spectrum of f-Hb-guided intervals was determined by using the Poisson regression model given the equivalent efficacy of a universal biennial screening. The use of FIT and colonoscopy for the pragmatic f-Hb-guided interval group was measured compared with the universal biennial screening group. Data analysis was performed from September 2022 to October 2023.

Results

Using data from the 3 500 250 participants (mean [SD] age, 57.8 [6.0] years) enrolled in the Taiwanese biennial nationwide FIT screening program, an incremental increase in baseline f-Hb associated with colorectal neoplasia and CRC mortality consistently was observed. Participants with different f-Hb levels were classified into distinct risk categories. Various screening intervals by different f-Hb levels were recommended. Using the proposed f-Hb-guided screening intervals, it was found that the personalized method was imputed to reduce the number of FIT tests and colonoscopies by 49% and 28%, respectively, compared with the universal biennial screening.

Conclusion and Relevance

The gradient relationship between f-Hb and colorectal neoplasia and CRC mortality was used to develop personalized FIT screening with f-Hb-guided screening intervals. Such a precision interscreening interval led to the reduced use of FIT test and colonoscopy without compromising the effectiveness of universal biennial screening.

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.

The association between organised colorectal cancer screening strategies and reduction of its related mortality: a systematic review and meta-analysis

BACKGROUND

To assess the long-term association between organised colorectal cancer (CRC) screening strategies and CRC-relate mortality.

METHODS

We systematically reviewed studies on organised CRC screening through PubMed, Ovid Medline, Embase and Cochrane from the inception. We retrieved characteristics of organised CRC screening from included literature and matched mortality (over 50 years) of those areas from the International Agency for Research on Cancer in May 2023. The variations of mortality were reported via the age-standardised mortality ratio. A random-effects model was used to synthesis results.

RESULTS

We summarised 58 organised CRC screening programmes and recorded > 2.7 million CRC-related deaths from 22 countries where rollout screening programmes were performed. The CRC screening strategy with faecal tests (guaiac faecal occult blood test (gFOBT) or faecal immunochemical tests (FIT)) or colonoscopy as the primary screening offer was associated with a 41.8% reduction in mortality, which was higher than those offered gFOBT (4.4%), FIT (16.7%), gFOBT or FIT (16.2%), and faecal tests (gFOBT or FIT) or flexible sigmoidoscopy (16.7%) as primary screening test. The longer duration of screening was associated with a higher reduction in the pooled age-standardised mortality ratio. In particular, the pooled age-standardised mortality ratio became non-significant when the screening of FIT was implemented for less than 5 years.

CONCLUSIONS

A CRC screening programme running for > 5 years was associated with a reduction of CRC-related mortality. Countries with a heavy burden of CRC should implement sustainable, organised screening providing a choice between faecal tests and colonoscopy as a preferred primary test.

Treatment of patients with screen-detected colorectal cancer is less strenuous: a nationwide cohort study with long-term follow-up

OBJECTIVE

During the last two decades, organised colorectal cancer (CRC) screening has been widely implemented. It remains to be established if screen-detected CRC (SD-CRC) is associated with reduced long-term requirements for treatment as compared with patients with non-screen-detected CRC (NSD-CRC).

STUDY DESIGN AND METHODS

This nationwide cohort study evaluated differences in treatment and healthcare contacts from the date of diagnosis to two years after comparing patients with SD-CRC and NSD-CRC. Data were collected from national healthcare registers, including patients aged 50-75 years and diagnosed with CRC between January 1st 2014 and March 31st 2018. Analyses were stratified into UICC stages and adjusted for sex, 5-year age groups, type of cancer (colonic/rectal), and Charlson comorbidity index score to address healthy user bias.

RESULTS

In total, 12,040 patients were included, 4708 with SD-CRC and 7332 with NSD-CRC. In patients with SD-CRC, the duration of hospitalisation and rate of emergency surgery were reduced by 38 % (relative risk [RR] = 0.62) and 66 % (RR = 0.34), respectively. Moreover, this group was characterised by a 75 % reduction in oncological outpatient visits (RR = 0.35) and a reduced number of treatments with chemotherapy (RR = 0.57) and radiotherapy (RR = 0.50). There were no significant differences between the two populations in the rates of metastasectomy and the number of contacts with primary healthcare providers.

CONCLUSION

Compared to patients with NSD-CRC, patients with SD-CRC experience less hospitalisation and treatment within the first two years after diagnosis.

Adenoma location, size, and morphology are risk factors for FOBT false-negative results in inpatients with advanced colorectal adenoma

Recently, advanced adenoma (AA) has been recognized as a target for colorectal cancer (CRC) screening. However, the fecal occult blood test (FOBT), the primary non-invasive screening method, shows limited sensitivity in detecting AA. This study investigates the relationship between adenoma characteristics and FOBT false-negative results. In a retrospective cohort study conducted from 2015 to 2022, we examined 342 inpatients with AA who underwent colonoscopy and received qualitative FOBT. FOBT sensitivity was analyzed about various adenoma characteristics, and logistic regression models were employed to investigate the relationship between adenoma features and FOBT false-negative outcomes. FOBT sensitivity in AA inpatients was 52.63%. Significant differences in sensitivity were observed based on adenoma location (left vs. right), morphology (with or without pedunculation), and size (≤ 10 mm vs. > 10 mm). After adjusting for several potential confounders, FOBT showed a reduced false-negative rate in AA with large-sized (OR, 0.49; 95% CI 0.31-0.77), left-sided location (OR, 0.53; 95% CI 0.31-0.89), and pedunculated morphology (OR, 0.73; 95% CI 0.43-1.24). AA with large size, left-sided location, and pedunculated morphology independently contribute to a decreased rate of FOBT false-negative results. However, these adenoma characteristics are not actively modifiable. Therefore, novel non-invasive methods are needed to improve AA detection accuracy.

Geospatial analysis and participant characteristics associated with colorectal cancer screening participation in Alberta, Canada: a population-based cross-sectional study

BACKGROUND

Colorectal cancer (CRC) is a leading cause of death in Canada and early detection can prevent deaths through screening. However, CRC screening in Alberta, Canada remains suboptimal and varies by sociodemographic and health system characteristics, as well as geographic location. This study aimed to further the understanding of these participant and health system characteristics associated with CRC screening in Alberta and identify clusters of regions with higher rates of overdue or unscreened individuals.

METHODS

We included Albertans aged 52 to 74 as of December 31, 2019 (index date) and we used data from administrative health data sources and linked to the Alberta Colorectal Cancer Screening Program database to determine colorectal cancer screening rates. We used multivariable multinomial logistic regression analysis to investigate the relationship between sociodemographic, health system characteristics and participation in CRC screening. We used optimized Getis-Ord Gi* hot-spot analysis to identify hot and cold-spots in overdue for and no record of CRC screening.

RESULTS

We included 919,939 Albertans, of which 65% were currently up to date on their CRC screening, 21% were overdue, and 14% had no record of CRC screening. Compared to Albertans who were currently up to date, those who were in older age groups, those without a usual provider of care, those who were health system non-users, and those living in more deprived areas were more likely to have no record of screening. Areas with high number of Albertans with no record of screening were concentrated in the North and Central zones.

CONCLUSIONS

Our study showed important variation in colorectal cancer screening participation across sociodemographic, health system and geographical characteristics and identified areas with higher proportions of individuals who have no record of screening or are under-screened in Alberta, Canada.

Effect of aspirin, warfarin, and proton-pump inhibitors on performance of fecal immunochemical test in colorectal cancer screening: a systematic review and meta-analysis

This study aims to investigate the impact of antithrombotic agents and proton-pump inhibitors (PPIs) on fecal immunochemical test (FIT). PubMed, EMBASE, Web of Science, Cochrane Central, and Google Scholar were searched from inception until September 3, 2023. Studies comparing the diagnostic performance of FIT between medicine users and non-users in average-risk colorectal cancer screening populations were included. Pooled sensitivity, specificity, and positive predictive values (PPVs) for advanced neoplasia (AN) of FIT were compared by reporting pooled odds ratios (ORs) with 95% confidence intervals (CIs) using a random-effects model. Twenty-two studies enrolling 5,572,367 individuals were included. For aspirin, pooled sensitivity and specificity for AN were 57.2% and 88.4% in users versus 60.2% and 93.2% in non-users; while pooled ORs were 1.49 (95% CI 0.89-2.48, P = 0.13) and 0.72 (95% CI 0.62-0.83, P < 0.001), respectively. In subgroup analysis, there was no difference in sensitivity and specificity between the two groups at the cutoff of 20 μg Hb/g (P = 0.57 and 0.29, respectively) but a significantly lower specificity in users compared with non-users at lower cutoffs (P < 0.001). Moreover, a significantly lower PPVAN in users compared with non-users was observed after matching age and sex confounders (P = 0.001). Warfarin had no significant influence on PPVAN of FIT (P = 0.43). PPIs were associated with a significantly lower PPVAN in users (P < 0.001). Aspirin use was associated with lower specificity and PPV of FIT. Aspirin discontinuation before FIT to reduce false-positive results should be interpreted with caution given concerns about cardiovascular events. Increasing cutoff values of FIT in aspirin users may be another possible approach. Additionally, warfarin withdrawal before FIT is unnecessary but PPIs withdrawal before FIT is recommended to reduce false-positive results.

Less Invasive Primary Treatment for Colorectal Cancer After Implementation of National Screening: A Nationwide Cohort Study

BACKGROUND

The effect of organized colorectal cancer (CRC) screening on type of primary treatment remains sparsely investigated. This study evaluated the difference in primary treatment strategy between patients diagnosed with screen-detected (SD-CRC) and non-screen-detected colorectal cancer (NSD-CRC) in a national CRC screening program.

METHODS

This was a retrospective national register-based cohort study. Data on patients aged between 50 and 75 years and diagnosed with SD-CRC or NSD-CRC were retrieved from the national colorectal cancer screening database and the Danish Colorectal Cancer Group database. Outcomes related to surgical invasiveness were compared between the two cohorts. Differences were expressed as relative risks using log-binomial generalized linear regression models. UICC stage IV specific outcomes were analyzed using the same method. All analyses were adjusted for sex, age, type of cancer (colonic/rectal), and Charlson comorbidity index.

RESULTS

The study included 4707 patients with SD-CRC and 7328 with NSD-CRC. Therapeutic flexible endoscopy (SD-CRC: n = 636 vs. NSD-CRC: n = 334, RR: 2.50, P < 0.001), (robotic-assisted) laparoscopic resection ((n = 616 vs. n = 773, RR: 1.27, P < 0.001), n = 2759 vs. n = 3471, RR: 1.11, P < 0.001), and radical resection (n = 3890 vs. n = 4834, RR: 1.02, P = 0.002) were significantly more frequent in the SD-CRC group. The rates of emergency priority (n = 32 vs. n = 562, RR: 0.09, P < 0.001), open surgery (n = 391 vs. n = 1410, RR: 0.53, P < 0.001), supplementary organ resection (n = 259 vs. n = 860, RR: 0.56, P < 0.001), and stoma formation (n = 526 vs. n = 1040, RR: 0.89, P = 0.007) were significantly lower in the SD-CRC group. The rate of patients undergoing surgery with UICC stage IV disease was significantly higher in the SD-CRC group (SD-CRC: n = 262, NSD-CRC: n = 994, RR: 1.43, P < 0.001).

CONCLUSION

SD-CRC remained associated with less invasive primary surgical treatment following adjustment for potential healthy user bias. UICC stage IV disease may be less advanced in patients with SD-CRC.

Application of artificial intelligence in colorectal cancer screening by colonoscopy: Future prospects (Review)

Colorectal cancer (CRC) has become a severe global health concern, with the third‑high incidence and second‑high mortality rate of all cancers. The burden of CRC is expected to surge to 60% by 2030. Fortunately, effective early evidence‑based screening could significantly reduce the incidence and mortality of CRC. Colonoscopy is the core screening method for CRC with high popularity and accuracy. Yet, the accuracy of colonoscopy in CRC screening is related to the experience and state of operating physicians. It is challenging to maintain the high CRC diagnostic rate of colonoscopy. Artificial intelligence (AI)‑assisted colonoscopy will compensate for the above shortcomings and improve the accuracy, efficiency, and quality of colonoscopy screening. The unique advantages of AI, such as the continuous advancement of high‑performance computing capabilities and innovative deep‑learning architectures, which hugely impact the control of colorectal cancer morbidity and mortality expectancy, highlight its role in colonoscopy screening.

Association Between Socioeconomic Status and Adherence to Fecal Occult Blood Tests in Colorectal Cancer Screening Programs: Systematic Review and Meta-Analysis of Observational Studies

BACKGROUND

Screening adherence is important in reducing colorectal cancer (CRC) incidence and mortality. Disparity in CRC screening adherence was observed in populations of different socioeconomic status (SES), but the direction and strength of the association remained unclear.

OBJECTIVE

We aimed to systematically review all the observational studies that have analyzed the association between SES and adherence to organized CRC screening based on fecal occult blood tests.

METHODS

We systematically reviewed the studies in PubMed, Embase, and Web of Science and reference lists of relevant reviews from the inception of the database up until June 7, 2023. Individual SES, neighborhood SES, and small-area SES were included, while any SES aggregated by geographic areas larger than neighbors were excluded. Studies assessing SES with any index or score combining indicators of income, education, deprivation, poverty, occupation, employment, marital status, cohabitation, and others were included. A random effect model meta-analysis was carried out for pooled odds ratios (ORs) and relative risks for adherence related to SES.

RESULTS

Overall, 10 studies, with a total of 3,542,379 participants and an overall adherence rate of 64.9%, were included. Compared with low SES, high SES was associated with higher adherence (unadjusted OR 1.73, 95% CI 1.42-2.10; adjusted OR 1.53, 95% CI 1.28-1.82). In the subgroup of nonindividual-level SES, the adjusted association was significant (OR 1.57, 95% CI 1.26-1.95). However, the adjusted association was insignificant in the subgroup of individual-level SES (OR 1.46, 95% CI 0.98-2.17). As for subgroups of the year of print, not only was the unadjusted association significantly stronger in the subgroup of early studies (OR 1.97, 95% CI 1.59-2.44) than in the subgroup of late studies (OR 1.43, 95% CI 1.31-1.56), but also the adjusted one was significantly stronger in the early group (OR 1.86, 95% CI 1.43-2.42) than in the late group (OR 1.26, 95% CI 1.14-1.39), which was consistent and robust. Despite being statistically insignificant, the strength of the association seemed lower in studies that did not adjust for race and ethnicity (OR 1.31, 95% CI 1.21-1.43) than the overall estimate (OR 1.53, 95% CI 1.28-1.82).

CONCLUSIONS

The higher-SES population had higher adherence to fecal occult blood test-based organized CRC screening. Neighborhood SES, or small-area SES, was more competent than individual SES to be used to assess the association between SES and adherence. The disparity in adherence between the high SES and the low SES narrowed along with the development of interventions and the improvement of organized programs. Race and ethnicity were probably important confounding factors for the association.

National and subnational incidence, mortality and associated factors of colorectal cancer in China: A systematic analysis and modelling study

Background

Due to their known variation by geography and economic development, we aimed to evaluate the incidence and mortality of colorectal cancer (CRC) in China over the past decades and identify factors associated with CRC among the Chinese population to provide targeted information on disease prevention.

Methods

We conducted a systemic review and meta-analysis of epidemiolocal studies on the incidence, mortality, and associated factors of CRC among the Chinese population, extracting and synthesising data from eligible studies retrieved from seven global and Chinese databases. We pooled age-standardised incidence rates (ASIRs) and mortality rates (ASMRs) for each province, subregion, and the whole of China, and applied a joinpoint regression model and annual per cent changes (APCs) to estimate the trends of CRC incidence and mortality. We conducted random-effects meta-analyses to assess the effect estimates of identified associated risk factors.

Results

We included 493 articles; 271 provided data on CRC incidence or mortality, and 222 on associated risk factors. Overall, the ASIR of CRC in China increased from 2.75 to 19.39 (per 100 000 person-years) between 1972 and 2019 with a slowed-down growth rate (APC1 = 5.75, APC2 = 0.42), while the ASMR of CRC decreased from 12.00 to 7.95 (per 100 000 person-years) between 1974 and 2020 with a slight downward trend (APC = -0.89). We analysed 62 risk factors with synthesized data; 16 belonging to the categories of anthropometrics factors, lifestyle factors, dietary factors, personal histories and mental health conditions were graded to be associated with CRC risk among the Chinese population in the meta-analysis limited to the high-quality studies.

Conclusions

We found substantial variation of CRC burden across regions and provinces of China and identified several associated risk factors for CRC, which could help to guide the formulation of targeted disease prevention and control strategies.

Registration

PROSPERO: CRD42022346558.

Current Status and Emerging Trends in Colorectal Cancer Screening and Diagnostics

Colorectal cancer (CRC) is a prevalent and potentially fatal disease categorized based on its high incidences and mortality rates, which raised the need for effective diagnostic strategies for the early detection and management of CRC. While there are several conventional cancer diagnostics available, they have certain limitations that hinder their effectiveness. Significant research efforts are currently being dedicated to elucidating novel methodologies that aim at comprehending the intricate molecular mechanism that underlies CRC. Recently, microfluidic diagnostics have emerged as a pivotal solution, offering non-invasive approaches to real-time monitoring of disease progression and treatment response. Microfluidic devices enable the integration of multiple sample preparation steps into a single platform, which speeds up processing and improves sensitivity. Such advancements in diagnostic technologies hold immense promise for revolutionizing the field of CRC diagnosis and enabling efficient detection and monitoring strategies. This article elucidates several of the latest developments in microfluidic technology for CRC diagnostics. In addition to the advancements in microfluidic technology for CRC diagnostics, the integration of artificial intelligence (AI) holds great promise for further enhancing diagnostic capabilities. Advancements in microfluidic systems and AI-driven approaches can revolutionize colorectal cancer diagnostics, offering accurate, efficient, and personalized strategies to improve patient outcomes and transform cancer management.

An efficient strategy for evaluating new non-invasive screening tests for colorectal cancer: the guiding principles

OBJECTIVE

New screening tests for colorectal cancer (CRC) are rapidly emerging. Conducting trials with mortality reduction as the end point supporting their adoption is challenging. We re-examined the principles underlying evaluation of new non-invasive tests in view of technological developments and identification of new biomarkers.

DESIGN

A formal consensus approach involving a multidisciplinary expert panel revised eight previously established principles.

RESULTS

Twelve newly stated principles emerged. Effectiveness of a new test can be evaluated by comparison with a proven comparator non-invasive test. The faecal immunochemical test is now considered the appropriate comparator, while colonoscopy remains the diagnostic standard. For a new test to be able to meet differing screening goals and regulatory requirements, flexibility to adjust its positivity threshold is desirable. A rigorous and efficient four-phased approach is proposed, commencing with small studies assessing the test's ability to discriminate between CRC and non-cancer states (phase I), followed by prospective estimation of accuracy across the continuum of neoplastic lesions in neoplasia-enriched populations (phase II). If these show promise, a provisional test positivity threshold is set before evaluation in typical screening populations. Phase III prospective studies determine single round intention-to-screen programme outcomes and confirm the test positivity threshold. Phase IV studies involve evaluation over repeated screening rounds with monitoring for missed lesions. Phases III and IV findings will provide the real-world data required to model test impact on CRC mortality and incidence.

CONCLUSION

New non-invasive tests can be efficiently evaluated by a rigorous phased comparative approach, generating data from unbiased populations that inform predictions of their health impact.

Barriers and facilitators of colorectal cancer screening using the 5As framework: A systematic review of US studies

Despite clear evidence that regular screening reduces colorectal cancer (CRC) mortality and the availability of multiple effective screening options, CRC screening continues to be underutilized in the US. A systematic literature search of four databases - Ovid, Medline, EBSCHOhost, and Web of Science - was conducted to identify US studies published after 2017 that reported on barriers and facilitators to CRC screening adherence. Articles were extracted to categorize relevant CRC screening barriers or facilitators that were assessed against CRC screening outcomes using the 5As dimensions: Access, Affordability, Acceptance, Awareness, Activation. Sixty-one studies were included. Fifty determinants of screening within the 5As framework and two additional dimensions including Sociodemographics and Health Status were identified. The Sociodemographics, Access, and Affordability dimensions had the greatest number of studies included. The most common factor in the Access dimension was contact with healthcare systems, within the Affordability dimension was insurance, within the Awareness dimension was knowledge CRC screening, within the Acceptance dimension was health beliefs, within the Activation dimension was prompts and reminders, within the Sociodemographics dimension was race/ethnicity, and among the Health Status dimension was chronic disease history. Among all studies, contact with healthcare systems, insurance, race/ethnicity, age, and education were the most common factors identified. CRC screening barriers and facilitators were identified across individual, clinical, and sociocontextual levels. Interventions that consider multilevel strategies will most effectively increase CRC screening adherence.

Latin America and the Caribbean Code Against Cancer 1st Edition: Medical interventions including hormone replacement therapy and cancer screening

Prostate, breast, colorectal, cervical, and lung cancers are the leading cause of cancer in Latin America and the Caribbean (LAC) accounting for nearly 50% of cancer cases and cancer deaths in the region. Following the IARC Code Against Cancer methodology, a group of Latin American experts evaluated the evidence on several medical interventions to reduce cancer incidence and mortality considering the cancer burden in the region. A recommendation to limit the use of HRT was issued based on the risk associated to develop breast, endometrial, and ovarian cancer and on growing concerns related to the over-the-counter and without prescription sales, which in turn bias estimations on current use in LAC. In alignment with WHO breast and cervical cancer initiatives, biennial screening by clinical breast examination (performed by trained health professionals) from the age of 40 years and biennial screening by mammography from the age of 50 years to 74, as well as cervical screening by HPV testing (either self-sampling or provider-sampling) every 5-10 years for women aged 30-64 years, were recommended. The steadily increasing rates of colorectal cancer in LAC also led to recommend colorectal screening by occult blood testing every two years or by endoscopic examination of the colorectum every 10 years for both men and women aged 50-74 years. After evaluating the evidence, the experts decided not to issue recommendations for prostate and lung cancer screening; while there was insufficient evidence on prostate cancer mortality reduction by prostate-specific antigen (PSA) testing, there was evidence of mortality reduction by low-dose computed tomography (LDCT) targeting high-risk individuals (mainly heavy and/or long-term smokers) but not individuals with average risk to whom recommendations of this Code are directed. Finally, the group of experts adapted the gathered evidence to develop a competency-based online microlearning program for building cancer prevention capacity of primary care health professionals.

Noninvasive Colorectal Cancer Prevention Options in Older Adults

Colorectal cancer (CRC) is a leading cause of morbidity and mortality worldwide and its incidence increases with age. The proportion of older adults in the United States continues to rise, making CRC prevention a key health priority for our aging population. CRC is a largely preventable disease through screening and polyp surveillance, and noninvasive modalities represent an important option for older adults in whom the burdens and risks of invasive testing are higher compared with younger adults. This review highlights the evidence, risks, and benefits of noninvasive CRC screening and surveillance options in older adults and discusses the challenges of CRC prevention in this cohort.

Colonoscopy compliance and diagnostic yield in a large population-based colorectal cancer screening programme

OBJECTIVES

With the intention of providing a reference for secondary prevention, our study provides some insight on diagnostic yield of factors influencing compliance with colonoscopy and the presence of advanced adenomas (AA).

METHODS

We conducted large-scale CRC screening among local Tianjin residents aged 40-75 years between 2012 and 2019. A high-risk factor questionnaire (HRFQ) was distributed to each participant, followed by the performance of a fecal immunochemical test (FIT). Participants who tested positively for any of these items were advised to undergo a colonoscopy. Relevant basic information was collected from participants during CRC screening, and the screening data were sorted and analysed.

RESULTS

A total of 5,670,924 people participated in CRC screening by the end of 2019, including 275,708 people in the high-risk group, and 74,685 (27.1%) people who underwent colonoscopy. The results of the logistic regression model demonstrated that participants with a history of mucous bloody stool (OR = 8.20, 95% CI: 7.92, 8.50, p < 0.001), chronic diarrhea (OR = 5.73, 95% CI: 5.57, 5.89, p < 0.001), and higher level of education (OR = 1.87, 95% CI: 1.80, 1.93, p < 0.001) were more likely to comply with a colonoscopy. Several factors including age (70-75 years old:OR = 3.72, 95% CI: 2.71, 5.10, p < 0.001), and FIT( +) (OR = 1.65, 95% CI: 1.42,1.90, p < 0.001) were identified to be associated with the presence of AA.

CONCLUSIONS

Increased compliance with colonoscopy is urgently needed. Our findings can inform the design of future effective large-scale population-based CRC screening programmes.

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.

Performance of different colorectal cancer screening strategies: a long-term passive follow-up population-based screening program in Beijing, China

BACKGROUND

We aimed to assess the performance of the risk assessment questionnaire and fecal immunochemical test (FIT) in a population-based colorectal cancer (CRC) screening program to provide timely evidence for tailored screening strategies in China.

METHODS

This analysis was conducted using data from Beijing Cancer Screening Prospective Cohort Study (BCSPCS). A risk assessment questionnaire and FIT were selected as the primary screening methods, and participants with any positive results were referred to undergo a diagnostic colonoscopy.

RESULTS

From 2015 to 2020, 148,636 Beijing residents aged 40-69 years were invited from designated communities, with 147,807 finishing the risk assessment questionnaire and 115,606 (78.2%) completing the FIT. Among the 42,969 (29.1%) high-risk CRC participants, 23,824 (55.4%) underwent colonoscopy. One year after enrollment, all subjects were linked to the Beijing Cancer Registry (BCR) database and 241 cases of CRC were confirmed. The CRC incidence rate was 58.2/100,000 for the low-risk arm and 418.9/100,000 for the high-risk arm. For participants who underwent colonoscopy, 91 CRC cases were detected, with a detection rate of 91.9% and 63.7% of them were early-stage cases. Furthermore, the sensitivities of utilizing the risk assessment questionnaire alone, FIT alone, combined risk assessment questionnaire and FIT were 75.7%, 50.1%, and 95.1%, and the specificities were 75.3%, 87.3%, and 70.7%, respectively.

CONCLUSION

The Beijing CRC screening program can effectively detect early-onset CRC; however, the compliance with colonoscopy still needs to be improved.

Robotic endoscope with double-balloon and double-bend tube for colonoscopy

The insertion of conventional colonoscopes can sometimes cause patients to experience pain during the procedure owing to the stretching of the mesentery. In this study, a prototype of a robotic colonoscope with a double-balloon and double-bend tube based on the conventional double-balloon endoscope was developed to simplify insertion and prevent the overstretching of the colon. Both the outer and inner tubes were confirmed to be free from interference from wires and sheaths. Additionally, all functions such as tip bending, inflation and deflation of the balloons, and actuator-driven pulling and pushing of the inner tube were operated properly. During the insertion test, the device could be reached the cecum of a colon model in approximately 442 s when operated by a non-medical operator. In addition, the device did not overstretch the colon model, thereby suggesting that the insertion mechanism can follow the shape of the colon model. As a result, the developed mechanism has the potential to navigate through a highly-bent colon without overstretching.

Postponing colonoscopy for 6 months in high-risk population increases colorectal cancer detection in China

BACKGROUND AND AIMS

Colonoscopy is an important colorectal cancer (CRC) screening modality; however, not all high-risk groups identified by fecal immunochemical test (FIT) and/or high-risk factor questionnaire (HRFQ) undergo colonoscopy in time. The impact of delays in colonoscopy on CRC detection among high-risk populations remains poorly understood, warranting further clarification.

METHODS

A retrospective study was conducted among CRC high-risk population identified by Tianjin CRC screening program. According to the colonoscopy results after HRFQ and FIT, patients were classified into CRC, advanced adenoma, non-advanced adenoma, and normal groups. The time interval between CRC screening and colonoscopy was investigated and its relationship with colonoscopy results. Logistic regression was performed to explore the risk factors of CRC detection.

RESULTS

Among the high-risk population without a history of CRC or polyps, 49,810 underwent HRFQ, FIT, and colonoscopy, and a time interval of fewer than 6 months was found for 79.56% of patients (n = 39,630). People with positive FIT were more likely to undergo colonoscopy within 6 months, and detection rates of CRC and/or advanced adenoma were positively related to time intervals. Similar results were found in people with a negative FIT but positive HRFQ. A time interval longer than 6 months was a significant predictor of CRC detection in high-risk populations.

CONCLUSION

For high-risk people identified by CRC screening, especially those with a positive FIT, a time interval of 6 months was associated with an increased probability of CRC detection. Our findings emphasize that populations at high risk should undergo colonoscopy at least within 6 months.

Antithrombotic drug use does not affect the fecal immunochemical test PPV for colorectal cancer, but warfarin may have an impact in a Japanese cohort

BACKGROUND

The fecal immunochemical test (FIT) is used for colorectal cancer (CRC) screening. Patients on antithrombotic drugs (ATs) are often screened for CRC, but the effect of ATs on FIT results is controversial.

METHODS

We divided individuals with FIT-positive results into two groups, patients treated with and without ATs, and retrospectively compared invasive CRC rates, advanced neoplasia detection rates (ANDRs), adenoma detection rates (ADRs), and polyp detection rates (PDRs) between the two groups. We evaluated the factors influencing the FIT positive predictive value (PPV) using propensity matching, adjusting for age, sex, and bowel preparation.

RESULTS

We enrolled 2327 individuals (54.9% male; mean age, 66.7  ±  12.7 years). We grouped 463 individuals into the AT user group and 1864 into the nonuser group. Patients in the AT user group were significantly older and more likely to be male. After propensity score matching for age, sex, and Boston bowel preparation scale, the ADR and PDR in the AT user group were significantly lower than those in the nonuser group. Univariate logistic analysis revealed that multiple AT use (odds ratio [OR]: .39, p < 0.001) had the lowest OR for FIT PPV, followed by age- and sex-adjusted factors for the ADR and any AT use (OR: .67, p = 0.0007). No significant factors related to AT use were observed among age-adjusted predictive factors for invasive CRC, but warfarin use was a borderline significant positive predictive factor (OR: 2.23, p = 0.059).

CONCLUSION

AT use may not affect the PPV for detecting invasive CRC in patients with positive FIT results, but warfarin may have an impact.

Colonoscopic Screening and Risk of All-Cause and Colorectal Cancer Mortality in Young and Older Individuals

PURPOSE

The incidence of early-onset colorectal cancer (CRC) and associated mortality have been increasing. However, the potential benefits of CRC screening are largely unknown in young individuals. We aimed to evaluate the effect of CRC screening with colonoscopy on all-cause and CRC mortality among young (aged < 45 years) and older (aged ≥ 45 years) individuals.

Materials and Methods

This cohort study included 528,046 Korean adults free of cancer at baseline who underwent a comprehensive health examination. The colonoscopic screening group was defined as those who reported undergoing colonoscopy for CRC screening. Mortality follow-up until December 31, 2019 was ascertained based on nationwide death certificate data from the Korea National Statistical Office.

RESULTS

Colonoscopic screening was associated with a lower risk of all-cause mortality in both young and older individuals. Multivariable-adjusted time-dependent hazard ratios (95% confidence intervals) for all-cause mortality comparing ever- to never-screening were 0.86 (0.75-0.99) for young individuals and 0.71 (0.65-0.78) for older individuals. Colonoscopic screenings were also associated with a reduced risk of CRC mortality without significant interaction by age, although this association was significant only among participants aged ≥ 45 years, with corresponding time-dependent hazard ratios of 0.47 (0.15-1.44) for young individuals and 0.52 (0.31-0.87) for those aged ≥ 45 years.

CONCLUSION

Colonoscopic CRC screening decreased all-cause mortality among both young and older individuals, while significantly decreased CRC mortality was observed only in those aged ≥ 45 years. Screening initiation at an earlier age warrants more rigorous confirmatory studies.

Adenoma Detection Rate and Colorectal Cancer Risk in Fecal Immunochemical Test Screening Programs : An Observational Cohort Study

BACKGROUND

Colorectal cancer (CRC) screening programs based on fecal immunochemical tests (FITs) represent the standard of care for population-based interventions. Their benefit depends on the identification of neoplasia at colonoscopy after FIT positivity. Colonoscopy quality measured by adenoma detection rate (ADR) may affect screening program effectiveness.

OBJECTIVE

To examine the association between ADR and postcolonoscopy CRC (PCCRC) risk in a FIT-based screening program.

DESIGN

Retrospective population-based cohort study.

SETTING

Fecal immunochemical test-based CRC screening program between 2003 and 2021 in northeastern Italy.

PATIENTS

All patients with a positive FIT result who had a colonoscopy were included.

MEASUREMENTS

The regional cancer registry supplied information on any PCCRC diagnosed between 6 months and 10 years after colonoscopy. Endoscopists' ADR was categorized into 5 groups (20% to 39.9%, 40% to 44.9%, 45% to 49.9%, 50% to 54.9%, and 55% to 70%). To examine the association of ADR with PCCRC incidence risk, Cox regression models were fitted to estimate hazard ratios (HRs) and 95% CIs.

RESULTS

Of the 110 109 initial colonoscopies, 49 626 colonoscopies done by 113 endoscopists between 2012 and 2017 were included. After 328 778 person-years follow-up, 277 cases of PCCRC were diagnosed. Mean ADR was 48.3% (range, 23% and 70%). Incidence rates of PCCRC from lowest to highest ADR group were 13.13, 10.61, 7.60, 6.01, and 5.78 per 10 000 person-years. There was a significant inverse association between ADR and PCCRC incidence risk, with a 2.35-fold risk increase (95% CI, 1.63 to 3.38) in the lowest group compared with the highest. The adjusted HR for PCCRC associated with 1% increase in ADR was 0.96 (CI, 0.95 to 0.98).

LIMITATION

Adenoma detection rate is partly determined by FIT positivity cutoff; exact values may vary in different settings.

CONCLUSION

In a FIT-based screening program, ADR is inversely associated with PCCRC incidence risk, mandating appropriate colonoscopy quality monitoring in this setting. Increasing endoscopists' ADR may significantly reduce PCCRC risk.

PRIMARY FUNDING SOURCE

None.

Impact of colorectal cancer screening on incidence, mortality and surgery rates: Evidences from programs based on the fecal immunochemical test in Italy

Fecal immunochemical tests (FIT) are among the most commonly used tests for colorectal cancer (CRC) screening programs worldwide. However, no randomised controlled trials have been carried out evaluating the impact of FIT-based screening programs (FIT-progr) on CRC incidence and mortality rates. Italian FIT-progr represent one of the most widespread and established experience worldwide. This paper reviews the evidence on the impact of FIT-progr on CRC incidence, tumor stage at diagnosis, mortality and surgery rates, deriving from Italian routine programs, i.e., outside the research setting. Unfortunately, the application of FIT-progr in Italy can be considered as an unplanned experimental model, due to the differences between Regions, both in health system management and adherence of the target population to the screening programs. The analysis of the manuscripts considered in the review, confirms that FIT-progr are effective in reducing CRC incidence and mortality rates and in improving the rate of endoscopic treatment of early invasive lesions. The review also highlights that FIT-progr are less performing for proximal colon than for distal colon and rectum.

Faecal haemoglobin concentration predicts all-cause mortality

BACKGROUND

Population-based screening for colorectal cancer by a faecal immunochemical test (FIT) is recommended by the European Union. Detectable faecal haemoglobin can indicate colorectal neoplasia as well as other conditions. A positive FIT predicts an increased risk of death from colorectal cancer but might also predict an increased risk of all-cause mortality.

METHODS

A cohort of screening participants was followed using the Danish National Register of Causes of Death. Data were retrieved from the Danish Colorectal Cancer Screening Database supplemented with FIT concentrations. Colorectal cancer specific and all-cause mortality were compared between FIT concentration groups using multivariate cox proportional hazards regression models.

FINDINGS

In 444,910 Danes invited for the screening program, 25,234 (5·7%) died during a mean follow-up of 56·5 months. Colorectal cancer caused 1120 deaths. The risk of colorectal cancer death increased with the increasing FIT concentration. The hazard ratios ranged from 2·6 to 25·9 compared to individuals with FIT concentrations <4 μg hb/g faeces. Causes other than colorectal cancer caused 24,114 deaths. The risk of all-cause death increased with the increasing FIT concentration, with the hazard ratios ranging from 1·6 to 5·3 compared to individuals with FIT concentrations <4 μg hb/g faeces.

INTERPRETATION

The risk of colorectal cancer mortality increased with the increasing FIT concentrations even for FIT concentrations considered negative in all European screening programs. The risk of all-cause mortality was also increased for individuals with detectable faecal blood. For colorectal cancer specific mortality and all-cause mortality, the risk was increased at the FIT concentrations as low as 4-9 μg hb/g faeces.

FUNDING

The study was funded by the Odense University Hospital grants A3610 and A2359.

Assessing overdiagnosis of fecal immunological test screening for colorectal cancer with a digital twin approach

Evaluating the magnitude of overdiagnosis associated with stool-based service screening for colorectal cancer (CRC) beyond a randomized controlled trial is often intractable and understudied. We aim to estimate the proportion of overdiagnosis in population-based service screening programs for CRC with the fecal immunochemical test (FIT). The natural process of overdiagnosis-embedded disease was first built up to learn transition parameters that quantify the pathway of non-progressive and progressive screen-detected cases calibrated with sensitivity, while also taking competing mortality into account. The Markov algorithms were then developed for estimating these transition parameters based on Taiwan FIT service CRC screening data on 5,417,699 residents aged 50-69 years from 2004 to 2014. Following the digital twin design with the parallel universe structure for emulating the randomized controlled trial, the screened twin, mirroring the control group without screening, was virtually recreated by the application of the above-mentioned trained parameters to predict CRC cases containing overdiagnosis. The ratio of the predicted CRCs derived from the screened twin to the observed CRCs of the control group minus 1 was imputed to measure the extent of overdiagnosis. The extent of overdiagnosis for invasive CRCs resulting from FIT screening is 4.16% (95% CI: 2.61-5.78%). The corresponding figure is increased to 9.90% (95% CI: 8.41-11.42%) for including high grade dysplasia (HGD) and further inflated to 15.83% (95% CI: 15.23-16.46%) when the removal adenoma is considered. The modest proportion of overdiagnosis modelled by the digital twin method, dispensing with the randomized controlled trial design, suggests the harm done to population-based FIT service screening is negligible.

The Impact of a Six-Year Existing Screening Programme Using the Faecal Immunochemical Test in Flanders (Belgium) on Colorectal Cancer Incidence, Mortality and Survival: A Population-Based Study

The faecal immunochemical test (FIT) has been increasingly used for organised colorectal cancer (CRC) screening. We assessed the impact of a six-year existing FIT screening programme in Flanders (Belgium) on CRC incidence, mortality and survival. The Flemish CRC screening programme started in 2013, targeting individuals aged 50-74 years. Joinpoint regression was used to investigate trends of age-standardised CRC incidence and mortality among individuals aged 50-79 years (2004-2019). Their 5-year relative survival was calculated using the Ederer II method. We found that FIT screening significantly reduced CRC incidence, especially that of advanced-stage CRCs (69.8/100,000 in 2012 vs. 51.1/100,000 in 2019), with a greater impact in men. Mortality started to decline in men two years after organised screening implementation (annual reduction of 9.3% after 2015 vs. 2.2% before 2015). The 5-year relative survival was significantly higher in screen-detected (93.8%) and lower in FIT non-participant CRCs (61.9%) vs. FIT interval cancers and CRCs in never-invited cases (67.6% and 66.7%, respectively). Organised FIT screening in Flanders clearly reduced CRC incidence (especially advanced-stage) and mortality (in men, but not yet in women). Survival is significantly better in screen-detected cases vs. CRCs in unscreened people. Our findings support the implementation of FIT organised screening and the continued effort to increase uptake.

Advanced-stage CRC incidence patterns following the phased implementation of the CRC screening programme in the Netherlands

BACKGROUND AND AIMS

From 2014, the Dutch colorectal cancer (CRC) faecal immunochemical testing-based screening programme was gradually rolled out by birth cohort. We evaluated changes in advanced-stage CRC incidence by timing of invitation to further strengthen the evidence for the effectiveness of CRC screening.

METHODS

Data on advanced-stage CRC incidence in the period 2010-2019 by invitation cohort were collected through the Netherlands Cancer Registry. Crude rates of advanced-stage CRC incidence and cumulative advanced-stage CRC incidence were calculated. Observed advanced-stage CRC incidence and cumulative advanced-stage CRC incidence were compared with expected advanced-stage CRC incidence and cumulative advanced-stage CRC incidence by invitation cohort using trend lines extrapolating data prior to the introduction of screening.

RESULTS

For the invitation cohort that was first invited for screening in 2014, advanced-stage CRC incidence increased before the introduction of screening from 94.1 to 124.7 per 100,000 individuals in the period 2010-2013. In 2014, the observed increase was higher than in preceding years, to 184.9 per 100,000 individuals. Hereafter, a decrease in incidence was observed to levels below expected incidence based on trends before the introduction of screening. A similar pattern was observed for invitation cohorts in subsequent years, coinciding with the first invitation to the screening programme. In 2019, the observed incidence for all invitation cohorts remained below expected incidence. The cumulative advanced-stage CRC incidence in the 2014-2016 invitation cohorts was significantly lower than the expected cumulative CRC incidence in the period 2010-2019.

CONCLUSIONS

In the period 2014-2019, an increase in advanced-stage CRC incidence was observed for all invitation cohorts first invited for screening, followed by a decrease below expected incidence, following the pattern of the phased implementation. The cumulative advanced-stage CRC incidence in invitation cohorts invited for screening multiple times was lower than expected based on trends from the pre-screening era. These findings support a causal relationship between the introduction of the Dutch screening programme and a decrease in advanced-stage CRC incidence.

Integration of stool microbiota, proteome and amino acid profiles to discriminate patients with adenomas and colorectal cancer

BACKGROUND

Screening for colorectal cancer (CRC) reduces its mortality but has limited sensitivity and specificity. Aims We aimed to explore potential biomarker panels for CRC and adenoma detection and to gain insight into the interaction between gut microbiota and human metabolism in the presence of these lesions.

METHODS

This multicenter case-control cohort was performed between February 2016 and November 2019. Consecutive patients ≥18 years with a scheduled colonoscopy were asked to participate and divided into three age, gender, body-mass index and smoking status-matched subgroups: CRC (n = 12), adenomas (n = 21) and controls (n = 20). Participants collected fecal samples prior to bowel preparation on which proteome (LC-MS/MS), microbiota (16S rRNA profiling) and amino acid (HPLC) composition were assessed. Best predictive markers were combined to create diagnostic biomarker panels. Pearson correlation-based analysis on selected markers was performed to create networks of all platforms.

RESULTS

Combining omics platforms provided new panels which outperformed hemoglobin in this cohort, currently used for screening (AUC 0.98, 0.95 and 0.87 for CRC vs controls, adenoma vs controls and CRC vs adenoma, respectively). Integration of data sets revealed markers associated with increased blood excretion, stress- and inflammatory responses and pointed toward downregulation of epithelial integrity.

CONCLUSIONS

Integrating fecal microbiota, proteome and amino acids platforms provides for new biomarker panels that may improve noninvasive screening for adenomas and CRC, and may subsequently lead to lower incidence and mortality of colon cancer.

Third Asia-Pacific consensus recommendations on colorectal cancer screening and postpolypectomy surveillance

The Asia-Pacific region has the largest number of cases of colorectal cancer (CRC) and one of the highest levels of mortality due to this condition in the world. Since the publishing of two consensus recommendations in 2008 and 2015, significant advancements have been made in our knowledge of epidemiology, pathology and the natural history of the adenoma-carcinoma progression. Based on the most updated epidemiological and clinical studies in this region, considering literature from international studies, and adopting the modified Delphi process, the Asia-Pacific Working Group on Colorectal Cancer Screening has updated and revised their recommendations on (1) screening methods and preferred strategies; (2) age for starting and terminating screening for CRC; (3) screening for individuals with a family history of CRC or advanced adenoma; (4) surveillance for those with adenomas; (5) screening and surveillance for sessile serrated lesions and (6) quality assurance of screening programmes. Thirteen countries/regions in the Asia-Pacific region were represented in this exercise. International advisors from North America and Europe were invited to participate.

Risk Scoring Systems for Predicting the Presence of Colorectal Neoplasia by Fecal Immunochemical Test Results in Chinese Population

INTRODUCTION

Adherence to colonoscopy screening for colorectal cancer (CRC) is low in general populations, including those tested positive in the fecal immunochemical test (FIT). Developing tailored risk scoring systems by FIT results may allow for more accurate identification of individuals for colonoscopy.

METHODS

Among 807,109 participants who completed the primary tests in the first-round Shanghai CRC screening program, 71,023 attended recommended colonoscopy. Predictors for colorectal neoplasia were used to develop respective scoring systems for FIT-positive or FIT-negative populations using logistic regression and artificial neural network methods.

RESULTS

Age, sex, area of residence, history of mucus or bloody stool, and CRC in first-degree relatives were identified as predictors for CRC in FIT-positive subjects, while a history of chronic diarrhea and prior cancer were additionally included for FIT-negative subjects. With an area under the receiver operating characteristic curve of more than 0.800 in predicting CRC, the logistic regression-based systems outperformed the artificial neural network-based ones and had a sensitivity of 68.9%, a specificity of 82.6%, and a detection rate of 0.24% by identifying 17.6% subjects at high risk. We also reported an area under the receiver operating characteristic curve of about 0.660 for the systems predicting CRC and adenoma, with a sensitivity of 57.8%, a specificity of 64.6%, and a detection rate of 6.87% through classifying 38.1% subjects as high-risk individuals. The performance of the scoring systems for CRC was superior to the currently used method in Mainland, China, and comparable with the scoring systems incorporating the FIT results.

DISCUSSION

The tailored risk scoring systems may better identify high-risk individuals of colorectal neoplasia and facilitate colonoscopy follow-up. External validation is warranted for widespread use of the scoring systems.

The role of artificial intelligence based systems for cost optimization in colorectal cancer prevention programs

Colorectal Cancer (CRC) has seen a dramatic increase in incidence globally. In 2019, colorectal cancer accounted for 1.15 million deaths and 24.28 million disability-adjusted life-years (DALYs) worldwide. In India, the annual incidence rates (AARs) for colon cancer was 4.4 per 100,000. There has been a steady rise in the prevalence of CRC in India which may be attributed to urbanization, mass migration of population, westernization of diet and lifestyle practices and a rise of obesity and metabolic risk factors that place the population at a higher risk of CRC. Moreoever, CRC in India differs from that described in the Western countries, with a higher proportion of young patients and more patients presenting with an advanced stage. This may be due to poor access to specialized healthcare and socio-economic factors. Early identification of adenomatous colonic polyps, which are well-recognized pre-cancerous lesions, at the time of screening colonoscopy has been shown to be the most effective measure used for CRC prevention. However, colonic polyps are frequently missed during colonoscopy and moreover, these screening programs necessitate man-power, time and resources for processing resected polyps, that may hamper penetration and efficacy in mid- to low-income countries. In the last decade, there has been significant progress made in the automatic detection of colonic polyps by multiple AI-based systems. With the advent of better AI methodology, the focus has shifted from mere detection to accurate discrimination and diagnosis of colonic polyps. These systems, once validated, could usher in a new era in Colorectal Cancer (CRC) prevention programs which would center around “Leave in-situ” and “Resect and discard” strategies. These new strategies hinge around the specificity and accuracy of AI based systems in correctly identifying the pathological diagnosis of the polyps, thereby providing the endoscopist with real-time information in order to make a clinical decision of either leaving the lesion in-situ (mucosal polyps) or resecting and discarding the polyp (hyperplastic polyps). The major advantage of employing these strategies would be in cost optimization of CRC prevention programs while ensuring good clinical outcomes. The adoption of these AI-based systems in the national cancer prevention program of India in accordance with the mandate to increase technology integration could prove to be cost-effective and enable implementation of CRC prevention programs at the population level. This level of penetration could potentially reduce the incidence of CRC and improve patient survival by enabling early diagnosis and treatment. In this review, we will highlight key advancements made in the field of AI in the identification of polyps during colonoscopy and explore the role of AI based systems in cost optimization during the universal implementation of CRC prevention programs in the context of mid-income countries like India.

Cost-effectiveness of colorectal cancer screening in Slovakia

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Colorectal Cancer Screening in a Changing World

Early detection of colorectal neoplasia significantly reduces mortality from colorectal cancer (CRC), and numerous screening options exist. Guidelines for CRC screening from US and international professional societies provide menus of options based on strength of evidence. Despite availability of screening and its proven impact, 40% of guideline-eligible patients are not screened as recommended in the United States. Adherence to or uptake of CRC screening is especially poor among underserved populations, including those with low income and African American and Hispanic populations. Consideration of screening options must not only take into account test performance, but issues of resources and individual versus population benefits.

The impact of COVID-19 pandemic in the diagnosis and management of colorectal cancer patients

The novel coronavirus disease 2019 (COVID-19) pandemic has posed an unprecedented challenge to healthcare systems worldwide, causing downscaling of almost all other activities, especially in its early stages. Currently, the availability of vaccines along with the spread of new viral variants has modified the epidemiology of the disease, and the previous activity is being gradually resumed in most healthcare facilities. In this review, we have summarized the influence of the COVID-19 pandemic in the diagnosis and management of colorectal cancer (CRC) patients. Population-based screening with either colonoscopy or fecal occult blood tests has proven to reduce CRC incidence and mortality, so screening programs have been implemented in most western countries. However, during the first COVID-19 wave, most of these programs had to be disrupted temporarily. In this review, we have thoroughly analyzed the consequences of these disruptions of screening programs as well as of the forced delays in diagnostic and therapeutic services on CRC prognosis, although its exact impact cannot be exactly measured yet. In any way, strategies to minimize its effect, such as catch-up strategies expanding the colonoscopy capacity or using fecal occult blood concentration and other risk factors to prioritize patients, are urgently needed. The COVID-19 pandemic has also led to a change in CRC patient presentation, with an overall temporary decreased incidence due to postponed diagnoses, but with more patients presenting in need of an emergency admission or with symptoms. Finally, changes in treatment approaches in CRC patients have been reported during the pandemic, namely a drop in the proportion of laparoscopic surgeries or a rise in short-term radiotherapy courses. We have therefore aimed to summarize the available evidence to guide the healthcare professionals treating CRC patients to choose the best treatment options in the current pandemic situation.

Implementing precision medicine in endoscopy practice

In contrast to the "one-size-fits-all" approach, precision medicine focuses on providing health care tailored to individual variabilities. Implementing precision medicine in endoscopy practice involves selecting the appropriate procedures among the endoscopic armamentarium in the diagnosis and management of patients in a logical sequence, jointly considering the pretest probabilities of possible diagnoses, patients' comorbidities and preference, and risk-benefit ratio of the individual procedures given the clinical scenario. The aim of this review is to summarize evidence-supported strategies and measures that may enhance precision medicine in general endoscopy practice.

Feasibility of Support by Family Practitioners in Reducing Colorectal Cancer-Related Death among Outpatients Who Have Not Undergone Colorectal Cancer Screening

We aimed to clarify the effectiveness of interventions in outpatients who did not undergo colorectal cancer (CRC) screening. From September 2012 to August 2013, we conducted a project, which showed that the immunological fecal occult blood test (FOBT) was actively recommended for outpatients who were ≥40 years of age, attended the Marumori Hospital regularly, and were not screened for CRC in the previous two years. We evaluated the detection rate of CRC and the disease specific survival ratio in February 2021 among patients with positive FOBT results during the retrospective cohort study. Overall, 388 (91%) out of the 425 outpatients submitted their stool samples. Among 388 outpatients, 66 tested positive for FOBT. While both the positive rate of FOBT and the detection rate of CRC (17% and 0.77%, respectively) were significantly higher than those in the nationwide administrative examination (5.7% and 0.13%, respectively) (p < 0.05), there was no statistically significant difference in the detection rate, compared with the group aged 65 years and older in the nationwide administrative examination. The 7-year CRC-specific survival ratio was 98.5%. Active promotion of FOBT at primary care institutions for outpatients who did not undergo CRC screening may contribute to reducing the frequency of CRC-related deaths.