Aspirin and cancer treatment: systematic reviews and meta-analyses of evidence: for and against.

Aspirin as a possible treatment of cancer has been of increasing interest for over 50 years, but the balance of the risks and benefits remains a point of contention. We summarise the valid published evidence 'for' and 'against' the use of aspirin as a cancer treatment and we present what we believe are relevant ethical implications. Reasons for aspirin include the benefits of aspirin taken by patients with cancer upon relevant biological cancer mechanisms. These explain the observed reductions in metastatic cancer and vascular complications in cancer patients. Meta-analyses of 118 observational studies of mortality in cancer patients give evidence consistent with reductions of about 20% in mortality associated with aspirin use. Reasons against aspirin use include increased risk of a gastrointestinal bleed though there appears to be no valid evidence that aspirin is responsible for fatal gastrointestinal bleeding. Few trials have been reported and there are inconsistencies in the results. In conclusion, given the relative safety and the favourable effects of aspirin, its use in cancer seems justified, and ethical implications of this imply that cancer patients should be informed of the present evidence and encouraged to raise the topic with their healthcare team.

Perceptions of the Impact of Comorbidity on the Bowel Cancer Screening Programme: Qualitative Study With Bowel Screening Participants and Staff.

INTRODUCTION: The impact of multiple health conditions on bowel cancer screening is currently unknown. We explored the impact of multiple health conditions on bowel cancer screening perceptions, experience and clinical management decisions following a positive stool test. METHODS: Semi-structured qualitative interviews were conducted remotely with Bowel Screening Wales staff (n = 16) stratified by regional location and role and with screening participants (n = 19) stratified by age, gender and comorbidity. Interview topics were guided by the Common-Sense Model. RESULTS: Screening participants, regardless of comorbidity status, placed great emphasis on the importance of early detection of cancer and completing the bowel screening process. Screening staff emphasised comorbidities in the clinical decision-making process; however, screening participants had low awareness of the impact that comorbidities can have on bowel screening. Participants describe how the presence of multiple health conditions can mask potential bowel symptoms and influence beliefs about follow-up. CONCLUSION: Bowel screening staff try to individualise the service to meet participant needs. The potential mismatch in screening staff and participant awareness and expectations of the bowel screening and diagnostic process needs to be addressed. Clearer and more regular communication with screening participants could support the screening process, particularly for those with significant coexisting health conditions or facing time delays. The possible masking effects and misattribution of symptoms because of comorbidities highlight an opportunity for education and raising awareness for screening participants and a potential area of focus for discussions in clinical consultations and staff training. PATIENT AND PUBLIC CONTRIBUTION: Project funding included costs for patients and public contributors to be compensated for their contributions to the project, in line with current standards. A patient and public contributor was involved in the design of the study, including protocol development, and the interpretation of key findings and implications for patients, which are subsequently reflected within the manuscript.

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.

Comparison of recommendations for surveillance of advanced colorectal polyps: A systematic review of guidelines.

BACKGROUND AND AIM: Patients diagnosed with advanced colorectal lesions have a higher risk of developing colorectal cancer. International polyp surveillance guidelines have recently been updated. The aim of this systematic review was to assess surveillance recommendations for advanced colorectal polyps and compare the patient, polyp, and colonoscopy quality factors considered in their recommendations. METHODS: Guidelines with surveillance recommendations for colorectal polyps were identified. Databases searched included PubMed, Web of Science, Scopus, TripPro, and guidelines identified by two blinded reviewers. The review protocol was registered on PROSPERO and performed in line with PRISMA guidelines. RESULTS: Six guidelines from the US Multi-Society Task Force, British Society of Gastroenterology, Cancer Council Australia, European Society of Gastrointestinal Endoscopy, Japan Gastroenterological Endoscopy Society, and Asia-Pacific Working Group on Colorectal Cancer Screening were included. The recommended surveillance interval of 3 years was consistent, but the criteria used for advanced polyps were variable. Polyp factors were the key determinant for when surveillance should be performed. Although all guidelines recognized their importance, the application of and evidence underlying patient characteristics and the quality of baseline colonoscopy were limited. All included guidelines were rated of average to high quality by the AGREE II instrument. CONCLUSION: Surveillance guidelines for advanced colorectal polyps are of good quality but limited by their underlying evidence. Standardization of definitions would be valuable for both research and clinical application. Better knowledge of colonoscopist quality indicators and patient factors is recommended to further economize surveillance recommendations, minimize patient risk, and achieve optimal outcomes without increasing pressure on services.

Participants' experiences of the management of screen-detected complex polyps within a structured bowel cancer screening programme.

BACKGROUND: The Bowel Screening Wales complex polyp removal service was introduced to address variations in surgery rates for screen-detected complex benign colorectal polyps, to improve the quality of the screening service and to make management of these polyps more equitable across Wales. Little is known about patient experiences and the potential impact on quality of life when undergoing complex polyp removal. This study is part of a wider research programme evaluating the decision-making, pathways and outcomes from complex polyp removal. OBJECTIVE: This study aimed to understand experiences of having a complex polyp removed and how this may influence quality of life. DESIGN: Semi-structured telephone interviews were conducted, and a thematic approach was used for data analysis. SETTING AND PARTICIPANTS: All participants had a complex polyp removed after a positive stool test and review by Bowel Screening Wales' Network Multi-Disciplinary Team. RESULTS: Twenty-one participants were interviewed. Most participants had their complex polyps removed endoscopically and reported no or minor problems or negative outcomes following their procedure. For a small minority, worse problems (e.g., pain, bowel dysfunction) and negative outcomes (e.g., cancer) followed their procedures. Most participants felt supported and reassured throughout their procedures. Any physical and emotional changes to quality of life were mainly linked to procedure outcomes. DISCUSSION: Experiences of complex polyp removal were generally positive, with minimal changes in quality of life. CONCLUSIONS: While most people had a positive experience of having a complex polyp removed, support initiatives, such as counselling or signposting to coping strategies, may be helpful to reduce any potential negative effects of procedures on quality of life. PATIENT OR PUBLIC CONTRIBUTION: Four patient and public involvement partners provided feedback on participant materials.

Water-assisted colonoscopy: an international modified Delphi review on definitions and practice recommendations.

BACKGROUND AND AIMS: Since 2008, a plethora of research studies has compared the efficacy of water-assisted (aided) colonoscopy (WAC) and underwater resection (UWR) of colorectal lesions with standard colonoscopy. We reviewed and graded the research evidence with potential clinical application. We conducted a modified Delphi consensus among experienced colonoscopists on definitions and practice of water immersion (WI), water exchange (WE), and UWR. METHODS: Major databases were searched to obtain research reports that could potentially shape clinical practice related to WAC and UWR. Pertinent references were graded (Grading of Recommendations, Assessment, Development and Evaluation). Extracted data supporting evidence-based statements were tabulated and provided to respondents. We received responses from 55 (85% surveyed) experienced colonoscopists (37 experts and 18 nonexperts in WAC) from 16 countries in 3 rounds. Voting was conducted anonymously in the second and third round, with ≥80% agreement defined as consensus. We aimed to obtain consensus in all statements. RESULTS: In the first and the second modified Delphi rounds, 20 proposed statements were decreased to 14 and then 11 statements. After the third round, the combined responses from all respondents depicted the consensus in 11 statements (S): definitions of WI (S1) and WE (S2), procedural features (S3-S5), impact on bowel cleanliness (S6), adenoma detection (S7), pain score (S8), and UWR (S9-S11). CONCLUSIONS: The most important consensus statements are that WI and WE are not the same in implementation and outcomes. Because studies that could potentially shape clinical practice of WAC and UWR were chosen for review, this modified Delphi consensus supports recommendations for the use of WAC in clinical practice.

Multidisciplinary decision-making strategies may reduce the need for secondary surgery in complex colonic polyps - A systematic review and pooled analysis.

AIM: The recognition of complex colonic polyps is increasing. Management varies considerably and the impact of this on clinical outcomes is unclear. The aim of this systematic review was to assess the impact of group decision-making strategies and defined selection criteria on the treatment outcomes of complex colonic polyps. METHOD: A systematic literature review identified studies reporting complex polyp treatment outcomes and describing their decision-making strategies. Databases searched included PubMed, Web of Science, CINAHL and Scopus. Articles were identified by two blinded reviewers using defined inclusion criteria. The review protocol was registered on PROSPERO and performed in line with PRISMA guidelines. RESULTS: There were 303 identified articles describing treatment outcomes of complex colonic polyps. Only nine of these fully described the decision-making strategy and met the inclusion criteria. Adverse events ranged from 1.3% to 10% across the studies. Unsuspected malignancy and secondary surgery rates ranged from 2.4% to 15.4% and 3.3% to 43.9%, respectively. Grouping of articles into a hierarchy of decision-making strategies demonstrated a sequential reduction in secondary surgery rates with improving strategies. There were no differences in comparisons of adverse event or unsuspected malignancy rates. CONCLUSIONS: There is limited description of decision-making strategies and variability in reporting of studies describing complex polyp treatment outcomes. The use of multidisciplinary decision-making and defined selection criteria may reduce the need for secondary surgical intervention in complex colonic polyps, but further evidence is required to draw definite conclusions.

Development and user-testing of a brief decision aid for aspirin as a preventive approach alongside colorectal cancer screening.

BACKGROUND: Several epidemiological and cohort studies suggest that regular low-dose aspirin use independently reduces the long-term incidence and risk of colorectal cancer deaths by approximately 20%. However, there are also risks to aspirin use, mainly gastrointestinal bleeding and haemorrhagic stroke. Making informed decisions depends on the ability to understand and weigh up benefits and risks of available options. A decision aid to support people to consider aspirin therapy alongside participation in the NHS bowel cancer screening programme may have an additional impact on colorectal cancer prevention. This study aims to develop and user-test a brief decision aid about aspirin to enable informed decision-making for colorectal screening-eligible members of the public. METHODS: We undertook a qualitative study to develop an aspirin decision aid leaflet to support bowel screening responders in deciding whether to take aspirin to reduce their risk of colorectal cancer. The iterative development process involved two focus groups with public members aged 60-74 years (n = 14) and interviews with clinicians (n = 10). Interviews (n = 11) were used to evaluate its utility for decision-making. Analysis was conducted using a framework approach. RESULTS: Overall, participants found the decision aid acceptable and useful to facilitate decision-making. They expressed a need for individualised risk information, more detail about the potential risks of aspirin, and preferred risk information presented in pictograms when offered different options. Implementation pathways were discussed, including the possibility of involving different clinicians in the process such as GPs and/or community pharmacists. A range of potentially effective timepoints for sending out the decision aid were identified. CONCLUSION: An acceptable and usable decision aid was developed to support decisions about aspirin use to prevent colorectal cancer.

Guidelines for the management of hereditary colorectal cancer from the British Society of Gastroenterology (BSG)/Association of Coloproctology of Great Britain and Ireland (ACPGBI)/United Kingdom Cancer Genetics Group (UKCGG).

Heritable factors account for approximately 35% of colorectal cancer (CRC) risk, and almost 30% of the population in the UK have a family history of CRC. The quantification of an individual's lifetime risk of gastrointestinal cancer may incorporate clinical and molecular data, and depends on accurate phenotypic assessment and genetic diagnosis. In turn this may facilitate targeted risk-reducing interventions, including endoscopic surveillance, preventative surgery and chemoprophylaxis, which provide opportunities for cancer prevention. This guideline is an update from the 2010 British Society of Gastroenterology/Association of Coloproctology of Great Britain and Ireland (BSG/ACPGBI) guidelines for colorectal screening and surveillance in moderate and high-risk groups; however, this guideline is concerned specifically with people who have increased lifetime risk of CRC due to hereditary factors, including those with Lynch syndrome, polyposis or a family history of CRC. On this occasion we invited the UK Cancer Genetics Group (UKCGG), a subgroup within the British Society of Genetic Medicine (BSGM), as a partner to BSG and ACPGBI in the multidisciplinary guideline development process. We also invited external review through the Delphi process by members of the public as well as the steering committees of the European Hereditary Tumour Group (EHTG) and the European Society of Gastrointestinal Endoscopy (ESGE). A systematic review of 10 189 publications was undertaken to develop 67 evidence and expert opinion-based recommendations for the management of hereditary CRC risk. Ten research recommendations are also prioritised to inform clinical management of people at hereditary CRC risk.

British Society of Gastroenterology/Association of Coloproctology of Great Britain and Ireland/Public Health England post-polypectomy and post-colorectal cancer resection surveillance guidelines.

These consensus guidelines were jointly commissioned by the British Society of Gastroenterology (BSG), the Association of Coloproctology of Great Britain and Ireland (ACPGBI) and Public Health England (PHE). They provide an evidence-based framework for the use of surveillance colonoscopy and non-colonoscopic colorectal imaging in people aged 18 years and over. They are the first guidelines that take into account the introduction of national bowel cancer screening. For the first time, they also incorporate surveillance of patients following resection of either adenomatous or serrated polyps and also post-colorectal cancer resection. They are primarily aimed at healthcare professionals, and aim to address:Which patients should commence surveillance post-polypectomy and post-cancer resection?What is the appropriate surveillance interval?When can surveillance be stopped? two or more premalignant polyps including at least one advanced colorectal polyp (defined as a serrated polyp of at least 10 mm in size or containing any grade of dysplasia, or an adenoma of at least 10 mm in size or containing high-grade dysplasia); or five or more premalignant polyps The Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument provided a methodological framework for the guidelines. The BSG's guideline development process was used, which is National Institute for Health and Care Excellence (NICE) compliant.two or more premalignant polyps including at least one advanced colorectal polyp (defined as a serrated polyp of at least 10 mm in size or containing any grade of dysplasia, or an adenoma of at least 10 mm in size or containing high-grade dysplasia); or five or more premalignant polyps The key recommendations are that the high-risk criteria for future colorectal cancer (CRC) following polypectomy comprise either:two or more premalignant polyps including at least one advanced colorectal polyp (defined as a serrated polyp of at least 10 mm in size or containing any grade of dysplasia, or an adenoma of at least 10 mm in size or containing high-grade dysplasia); or five or more premalignant polyps This cohort should undergo a one-off surveillance colonoscopy at 3 years. Post-CRC resection patients should undergo a 1 year clearance colonoscopy, then a surveillance colonoscopy after 3 more years.

The impact of chromoendoscopy for surveillance of the duodenum in patients with MUTYH-associated polyposis and familial adenomatous polyposis.

BACKGROUND AND AIMS: Duodenal polyposis and cancer have become a key issue for patients with familial adenomatous polyposis (FAP) and MUTYH-associated polyposis (MAP). Almost all patients with FAP will develop duodenal adenomas, and 5% will develop cancer. The incidence of duodenal adenomas in MAP appears to be lower than in FAP, but the limited available data suggest a comparable increase in the relative risk and lifetime risk of duodenal cancer. Current surveillance recommendations, however, are the same for FAP and MAP, using the Spigelman score (incorporating polyp number, size, dysplasia, and histology) for risk stratification and determination of surveillance intervals. Previous studies have demonstrated a benefit of enhanced detection rates of adenomas by use of chromoendoscopy both in sporadic colorectal disease and in groups at high risk of colorectal cancer. We aimed to assess the effect of chromoendoscopy on duodenal adenoma detection, to determine the impact on Spigelman stage and to compare this in individuals with known pathogenic mutations in order to determine the difference in duodenal involvement between MAP and FAP. METHODS: A prospective study examined the impact of chromoendoscopy on the assessment of the duodenum in 51 consecutive patients with MAP and FAP in 2 academic centers in the United Kingdom (University Hospital Llandough, Cardiff, and St Mark's Hospital, London) from 2011 to 2014. RESULTS: Enhanced adenoma detection of 3 times the number of adenomas after chromoendoscopy was demonstrated in both MAP (P = .013) and FAP (P = .002), but did not affect adenoma size. In both conditions, there was a significant increase in Spigelman stage after chromoendoscopy compared with endoscopy without dye spray. Spigelman scores and overall adenoma detection was significantly lower in MAP compared with FAP. CONCLUSIONS: Chromoendoscopy improved the diagnostic yield of anomas in MAP and FAP 3-fold, and in both MAP and FAP this resulted in a clinically significant upstaging in Spigelman score. Further studies are required to determine the impact of improved adenoma detection on the management and outcome of duodenal polyposis.

British Society of Gastroenterology position statement on serrated polyps in the colon and rectum.

Serrated polyps have been recognised in the last decade as important premalignant lesions accounting for between 15% and 30% of colorectal cancers. There is therefore a clinical need for guidance on how to manage these lesions; however, the evidence base is limited. A working group was commission by the British Society of Gastroenterology (BSG) Endoscopy section to review the available evidence and develop a position statement to provide clinical guidance until the evidence becomes available to support a formal guideline. The scope of the position statement was wide-ranging and included: evidence that serrated lesions have premalignant potential; detection and resection of serrated lesions; surveillance strategies after detection of serrated lesions; special situations-serrated polyposis syndrome (including surgery) and serrated lesions in colitis; education, audit and benchmarks and research questions. Statements on these issues were proposed where the evidence was deemed sufficient, and re-evaluated modified via a Delphi process until >80% agreement was reached. The Grading of Recommendations, Assessment, Development and Evaluations (GRADE) tool was used to assess the strength of evidence and strength of recommendation for finalised statements. Key recommendation: we suggest that until further evidence on the efficacy or otherwise of surveillance are published, patients with sessile serrated lesions (SSLs) that appear associated with a higher risk of future neoplasia or colorectal cancer (SSLs ≥10 mm or serrated lesions harbouring dysplasia including traditional serrated adenomas) should be offered a one-off colonoscopic surveillance examination at 3 years (weak recommendation, low quality evidence, 90% agreement).

British Society of Gastroenterology/Association of Coloproctologists of Great Britain and Ireland guidelines for the management of large non-pedunculated colorectal polyps.

These guidelines provide an evidence-based framework for the management of patients with large non-pedunculated colorectal polyps (LNPCPs), in addition to identifying key performance indicators (KPIs) that permit the audit of quality outcomes. These are areas not previously covered by British Society of Gastroenterology (BSG) Guidelines.A National Institute of Health and Care Excellence (NICE) compliant BSG guideline development process was used throughout and the Appraisal of Guidelines for Research and Evaluation (AGREE II) tool was used to structure the guideline development process. A systematic review of literature was conducted for English language articles up to May 2014 concerning the assessment and management of LNPCPs. Quality of evaluated studies was assessed using the Scottish Intercollegiate Guidelines Network (SIGN) Methodology Checklist System. Proposed recommendation statements were evaluated by each member of the Guideline Development Group (GDG) on a scale from 1 (strongly agree) to 5 (strongly disagree) with >80% agreement required for consensus to be reached. Where consensus was not reached a modified Delphi process was used to re-evaluate and modify proposed statements until consensus was reached or the statement discarded. A round table meeting was subsequently held to finalise recommendations and to evaluate the strength of evidence discussed. The GRADE tool was used to assess the strength of evidence and strength of recommendation for finalised statements.KPIs, a training framework and potential research questions for the management of LNPCPs were also developed. It is hoped that these guidelines will improve the assessment and management of LNPCPs.

PIGA Mutations and Glycosylphosphatidylinositol Anchor Dysregulation in Polyposis-Associated Duodenal Tumorigenesis.

The pathogenesis of duodenal tumors in the inherited tumor syndromes familial adenomatous polyposis (FAP) and MUTYH-associated polyposis (MAP) is poorly understood. This study aimed to identify genes that are significantly mutated in these tumors and to explore the effects of these mutations. Whole exome and whole transcriptome sequencing identified recurrent somatic coding variants of phosphatidylinositol N-acetylglucosaminyltransferase subunit A (PIGA) in 19/70 (27%) FAP and MAP duodenal adenomas, and further confirmed the established driver roles for APC and KRAS. PIGA catalyzes the first step in glycosylphosphatidylinositol (GPI) anchor biosynthesis. Flow cytometry of PIGA-mutant adenoma-derived and CRISPR-edited duodenal organoids confirmed loss of GPI anchors in duodenal epithelial cells and transcriptional profiling of duodenal adenomas revealed transcriptional signatures associated with loss of PIGA. IMPLICATIONS: PIGA somatic mutation in duodenal tumors from patients with FAP and MAP and loss of membrane GPI-anchors may present new opportunities for understanding and intervention in duodenal tumorigenesis.

Interobserver agreement in the reporting of colorectal polyp pathology among bowel cancer screening pathologists in Wales.

AIMS: To assess the interobserver agreement in the reporting of colorectal polyps among histopathologists participating in the Welsh Bowel Cancer Screening (BCS) programme. METHODS AND RESULTS: Twelve benign polyps representative of BCS cases were identified from pathology files and reported by 28 BCS histopathologists using proforma sheets. The level of agreement between the participants and a gold standard was determined using kappa (κ) statistics. A moderate level of agreement was achieved in the reporting of polyp type [κ = 0.45; 95% confidence interval (CI) 0.34-0.59] and adenomatous lesions were distinguished from non-adenomatous lesions in 96% of cases. Substantial agreement was obtained in distinguishing low- and high-grade dysplasias (κ = 0.67; 95% CI 0.50-0.86), but there was only fair agreement in reporting excision margin status (κ = 0.24; 95% CI 0.07-0.43) with frequent use of the 'uncertain' category. Significant issues included categorizing serrated lesions, recognizing focal high-grade dysplasia and epithelial misplacement, and apparent overdiagnosis of villous change in adenomas. CONCLUSIONS: Interobserver variability in some aspects of reporting colorectal polyps by BCS pathologists is suboptimal, with a potential impact upon patient management and the efficient running of the screening service. Approaches to addressing this are discussed.

Planning management for complex colorectal polyps: a qualitative assessment of factors influencing decision-making among colonoscopists.

OBJECTIVE: Endoscopic therapy is the recommended primary treatment for most complex colorectal polyps, but high colonic resection rates are reported. The aim of this qualitative study was to understand and compare between specialities, the clinical and non-clinical factors influencing decision making when planning management. DESIGN: Semi-structured interviews were performed among colonoscopists across the UK. Interviews were conducted virtually and transcribed verbatim. Complex polyps were defined as lesions requiring further management planning rather than those treatable at the time of endoscopy. A thematic analysis was performed. Findings were coded to identify themes and reported narratively. RESULTS: Twenty colonoscopists were interviewed. Four major themes were identified including gathering information regarding the patient and their polyp, aids to decision making, barriers in achieving optimal management and improving services. Participants advocated endoscopic management where possible. Factors such as younger age, suspicion of malignancy, right colon or difficult polyp location lead towards surgical intervention and were similar between surgical and medical specialties. Availability of expertise, timely endoscopy and challenges in referral pathways were reported barriers to optimal management. Experiences of team decision-making strategies were positive and advocated in improving complex polyp management. Recommendations based on these findings to improve complex polyp management are provided. CONCLUSION: The increasing recognition of complex colorectal polyps requires consistency in decision making and access to a full range of treatment options. Colonoscopists advocated the availability of clinical expertise, timely treatment and education in avoiding surgical intervention and providing good patient outcomes. Team decision-making strategies for complex polyps may provide an opportunity to coordinate and improve these issues.

Acceptability of alternative technologies compared with faecal immunochemical test and/or colonoscopy in colorectal cancer screening: A systematic review.

OBJECTIVE: Colorectal cancer (CRC) is the third most common cancer and the second largest cause of cancer-related death worldwide. Current CRC screening in various countries involves stool-based faecal immunochemical testing (FIT) and/or colonoscopy, yet public uptake remains sub-optimal. This review assessed the literature regarding acceptability of alternative CRC screening modalities compared to standard care in average-risk adults. METHOD: Systematic searches of MEDLINE, EMBASE, CINAHL, Cochrane and Web of Science were conducted up to February 3rd, 2022. The alternative interventions examined were computed tomography colonography, flexible sigmoidoscopy, colon capsule endoscopy and blood-based biomarkers. Outcomes for acceptability were uptake, discomfort associated with bowel preparation, discomfort associated with screening procedure, screening preferences and willingness to repeat screening method. A narrative data synthesis was conducted. RESULTS: Twenty-one studies met the inclusion criteria. Differences between intervention and comparison modalities in uptake did not reach statistical significance in most of the included studies. The findings do suggest FIT as being more acceptable as a screening modality than flexible sigmoidoscopy. There were no consistent significant differences in bowel preparation discomfort, screening procedure discomfort, screening preference and willingness to repeat screening between the standard care and alternative modalities. CONCLUSION: Current evidence comparing standard colonoscopy and stool-based CRC screening with novel modalities does not demonstrate any clear difference in acceptability. Due to the small number of studies available and included in each screening comparison and lack of observed differences, further research is needed to explore factors influencing acceptability of alternative CRC modalities that might result in improvement in population uptake within different contexts.

Systematic review of validity testing in colonoscopy simulation.

BACKGROUND: Simulation is a useful adjunct to skills-based training. It potentially avoids risk to patients during training and development of basic interventional techniques. This may be of particular relevance in colonoscopy where the learning curve can be long. Several endoscopic devices exist that simulate colonoscopy for training purposes. This study was designed to review the evidence for the validity of these simulators. METHODS: MEDLINE (1947 to present), PubMed, Embase classic + Embase, the metaRegister of Controlled Trials, and the Education Resources Information Center (ERIC) were searched for studies validating colonoscopy simulators. For each study, we recorded the type of simulator used, the tasks assessed, the endpoints reported, and the type of validity measured. Common endpoints between studies were compared, and the evidence was graded. RESULTS: Thirteen studies met the inclusion criteria. Construct validity was reported in five (41.7 %) studies for the Accutouch HT Immersion (cases 1, 3, and 4), four studies (33.3 %) for the GI mentor II (Simbionix) (Modules 1.1, 1.3, 1.7, 2.1, and 5), two studies (16.7 %) for the Olympus Endo Ts-1 2nd Generation, and one study for the Endo X bovine model. Face validity was reported for the Accutouch HT Immersion, the Olympus 2nd Generation, and the KAIST-Ewha. Content validity was reported for the all simulators, excluding the KAIST-Ewha. The only report of criterion validity was for the Endo X bovine model. CONCLUSION: Evidence exists to support the face, content, and construct validity of several virtual reality colonoscopy simulators for specific diagnostic and therapeutic modules with selected endpoints. One study demonstrates content, construct, and criterion validity for an ex vivo animal platform. Further work is needed to demonstrate the criterion validity of all devices.

Survey on the perceptions of UK gastroenterologists and endoscopists to artificial intelligence.

Background and aims: With the potential integration of artificial intelligence (AI) into clinical practice, it is essential to understand end users' perception of this novel technology. The aim of this study, which was endorsed by the British Society of Gastroenterology (BSG), was to evaluate the UK gastroenterology and endoscopy communities' views on AI. Methods: An online survey was developed and disseminated to gastroenterologists and endoscopists across the UK. Results: One hundred four participants completed the survey. Quality improvement in endoscopy (97%) and better endoscopic diagnosis (92%) were perceived as the most beneficial applications of AI to clinical practice. The most significant challenges were accountability for incorrect diagnoses (85%) and potential bias of algorithms (82%). A lack of guidelines (92%) was identified as the greatest barrier to adopting AI in routine clinical practice. Participants identified real-time endoscopic image diagnosis (95%) as a research priority for AI, while the most perceived significant barriers to AI research were funding (82%) and the availability of annotated data (76%). Participants consider the priorities for the BSG AI Task Force to be identifying research priorities (96%), guidelines for adopting AI devices in clinical practice (93%) and supporting the delivery of multicentre clinical trials (91%). Conclusion: This survey has identified views from the UK gastroenterology and endoscopy community regarding AI in clinical practice and research, and identified priorities for the newly formed BSG AI Task Force.