Strategies for Colorectal Cancer Screening.

The incidence of colorectal cancer (CRC) is increasing worldwide. CRC has high mortality when detected at advanced stages, yet it is also highly preventable. Given the difficulties in implementing major lifestyle changes or widespread primary prevention strategies to decrease CRC risk, screening is the most powerful public health tool to reduce mortality. Screening methods are effective but have limitations. Furthermore, many screen-eligible people remain unscreened. We discuss established and emerging screening methods, and potential strategies to address current limitations in CRC screening. A quantum step in CRC prevention might come with the development of new screening strategies, but great gains can be made by deploying the available CRC screening modalities in ways that optimize outcomes while making judicious use of resources.

Long-term Risk of Colorectal Cancer After Removal of Conventional Adenomas and Serrated Polyps.

BACKGROUND & AIMS: Endoscopic screening reduces incidence and mortality of colorectal cancer (CRC) because precursor lesions, such as conventional adenomas or serrated polyps, are removed. Individuals with polypectomies are advised to undergo colonoscopy surveillance to prevent CRC. However, guidelines for surveillance intervals after diagnosis of a precursor lesion, particularly for individuals with serrated polyps, vary widely, and lack sufficient supporting evidence. Consequently, some high-risk patients do not receive enough surveillance and lower-risk subjects receive excessive surveillance. METHODS: We examined the association between findings from first endoscopy and CRC risk among 122,899 participants who underwent flexible sigmoidoscopy or colonoscopy in the Nurses' Health Study 1 (1990-2012), Nurses' Health Study 2 (1989-2013), or the Health Professionals Follow-up Study (1990-2012). Endoscopic findings were categorized as no polyp, conventional adenoma, or serrated polyp (hyperplastic polyp, traditional serrated adenoma, or sessile serrated adenoma, with or without cytological dysplasia). Conventional adenomas were classified as advanced (≥10 mm, high-grade dysplasia, or tubulovillous or villous histology) or nonadvanced, and serrated polyps were assigned to categories of large (≥10 mm) or small (<10 mm). We used a Cox proportional hazards regression model to calculate the hazard ratios (HRs) of CRC incidence, after adjusting for various potential risk factors. RESULTS: After a median follow-up period of 10 years, we documented 491 incident cases of CRC: 51 occurred in 6161 participants with conventional adenomas, 24 in 5918 participants with serrated polyps, and 427 in 112,107 participants with no polyp. Compared with participants with no polyp detected during initial endoscopy, the multivariable HR for incident CRC in individuals with an advanced adenoma was 4.07 (95% confidence interval [CI] 2.89-5.72) and the HR for CRC in individuals with a large serrated polyp was 3.35 (95% CI 1.37-8.15). In contrast, there was no significant increase in risk of CRC in patients with nonadvanced adenomas (HR 1.21; 95% CI 0.68-2.16, P = .52) or small serrated polyps (HR 1.25; 95% CI 0.76-2.08; P = .38). CONCLUSIONS: These findings provide support for guidelines that recommend repeat lower endoscopy within 3 years of a diagnosis of advanced adenoma and large serrated polyps. In contrast, patients with nonadvanced adenoma or small serrated polyps may not require more intensive surveillance than patients without polyps.

Management of rectal cancer in Canada: an evidence-based comparison of clinical practice guidelines

Background: Rectal cancer requires a multidisciplinary and multimodality treatment approach. Clinical practice guidelines (CPGs) provide a framework for delivering consistent, evidence-based health care. We compared provincial/territorial CPGs across Canada to identify areas of variability and evaluate their quality. Methods: We retrieved CPGs from Canadian organizations responsible for cancer care oversight and evaluated their quality and developmental methodology using the AGREE-II instrument. Recommendations for diagnostic and staging investigations, treatment by stage, and post-treatment surveillance of stage I­III rectal cancers were abstracted and compared. Results: We identified 7 sets of CPGs for analysis, varying in content, presentation, quality, and year last updated. Differences were noted in locoregional staging: 4 recommended magnetic resonance imaging over endorectal ultrasonography, 2 recommended either modality, and 3 specified scenarios for one over the other. Recommendations also varied for use of staging computed tomography of the chest versus chest radiography and for surgical management and indications for transanal excision. Recommendations for neoadjuvant therapy in stage II/III disease also differed: 3 guidelines recommended long-course chemoradiation over short-course radiation therapy alone, while 3 others recommended short-course radiation in specific clinical scenarios. Adjuvant chemotherapy for stage II/III disease was uniformly recommended, with variable protocols. The use of proctosigmoidoscopy and interval/duration of endoscopic post-treatment surveillance varied among guidelines. Conclusion: Canadian CPGs vary in their recommendations for staging, treatment, and surveillance of rectal cancer. Some of these differences reflect areas with limited definitive evidence. Consistent guidelines with uniform implementation across provinces/territories may lead to more equitable care to patients.

Contexte: Le cancer rectal requiert une approche thérapeutique multidisciplinaire et multimodalité. Les guides de pratique clinique (GPC) procurent un cadre pour assurer la prestation de soins de santé constants reposant sur des données probantes. Nous avons comparé les GPC des provinces et des territoires canadiens pour identifier les secteurs où ils varient et pour en évaluer la qualité. Méthodes: Nous avons obtenu les GPC des organisations canadiennes responsables des soins oncologiques et nous avons évalué leur qualité et la méthodologie de leur élaboration au moyen de l'outil AGREE II (Appraisal of Guidelines for Research & Evaluation). Nous avons extrait et comparé les recommandations en ce qui concerne les épreuves diagnostiques et la stadification, les traitements en fonction du stade et la surveillance post-thérapeutique du cancer rectal de stade I à III. Résultats: Nous avons recensé 7 GPC aux fins de cette analyse; leur contenu, leur présentation, leur qualité et l'année de leur plus récente mise à jour variaient. Des différences ont été observées au plan de la stadification locorégionale : 4 recommandaient l'imagerie par résonnance magnétique plutôt que l'échographie endorectale, 2 recommandaient l'une ou l'autre et 3 précisaient des circonstances où utiliser l'une plutôt que l'autre. Les recommandations variaient aussi pour ce qui est de l'utilisation de la scintigraphie c. radiographie thoracique de stadification, de la prise en charge chirurgicale et des indications de l'excision transanale. Les recommandations variaient également en ce qui concerne le traitement néoadjuvant pour la maladie de stade II/III : 3 guides recommandaient un traitement par chimioradiothérapie à long terme plutôt qu'une brève radiothérapie seule, tandis que 3 autres recommandaient une radiothérapie brève dans certains cas particuliers. La chimiothérapie adjuvante pour la maladie de stade II/III était uniformément recommandée, mais les protocoles variaient. L'utilisation de la proctosigmoïdoscopie et l'intervalle/durée de la surveillance endoscopique post-thérapeutique variaient d'un guide à l'autre. Conclusion: Les GPC canadiens varient quant à leurs recommandations pour la stadification, le traitement et la surveillance du cancer rectal. Certaines de ces différences témoignent du manque de données probantes concluantes dans certains secteurs. L'uniformisation des guides et de leur application entre les provinces et les territoires pourrait faciliter une prestation plus équitable des soins aux patients.

Diagnostic Performance of One-off Flexible Sigmoidoscopy with Fecal Immunochemical Testing in a Large Screening Population.

BACKGROUND: Flexible sigmoidoscopy and fecal immunochemical tests are established diagnostic tests for colorectal cancer (CRC) screening and less invasive, less expensive, and easier to conduct than colonoscopy. However, little is known about their joint diagnostic performance compared with colonoscopy. We aimed to assess the expected diagnostic performance of joint use of flexible sigmoidoscopy and fecal immunochemical test. METHODS: We assessed the overall and site-specific prevalences of colorectal neoplasms and the overall sensitivity, specificity, area under the receiver operating characteristics curve of a quantitative fecal immunochemical test (FOB Gold, Sentinel Diagnostics, Milano, Italy) among 3,466 participants in screening colonoscopy in Germany. Results were used to model the expected diagnostic performance of joint use of flexible sigmoidoscopy and fecal immunochemical testing. RESULTS: CRC and advanced adenomas were found in 29 (1%) and 354 (10%) participants, respectively. The area under the curve of fecal immunochemical testing for these outcomes could be raised from 96% to 100% and from 70% to 89%, respectively, by combining it with flexible sigmoidoscopy. At 90% specificity, sensitivity of fecal immunochemical testing would increase from 97% to 100% for CRC and from 40% to 79% for advanced adenomas. CONCLUSIONS: Combining flexible sigmoidoscopy and fecal immunochemical testing might strongly enhance diagnostic performance of each single test to a level close to the diagnostic performance of screening colonoscopy while avoiding many unnecessary colonoscopies.

Changes in scoring of Direct Observation of Procedural Skills (DOPS) forms and the impact on competence assessment.

BACKGROUND: Direct Observation of Procedural Skills (DOPS) is an established competence assessment tool in endoscopy. In July 2016, the DOPS scoring format changed from a performance-based scale to a supervision-based scale. We aimed to evaluate the impact of changes to the DOPS scale format on the distribution of scores in novice trainees and on competence assessment. METHODS: We performed a prospective, multicenter (n = 276), observational study of formative DOPS assessments in endoscopy trainees with ≤ 100 lifetime procedures. DOPS were submitted in the 6-months before July 2016 (old scale) and after (new scale) for gastroscopy (n = 2998), sigmoidoscopy (n = 1310), colonoscopy (n = 3280), and polypectomy (n = 631). Scores for old and new DOPS were aligned to a 4-point scale and compared. RESULTS: 8219 DOPS (43 % new and 57 % old) submitted for 1300 trainees were analyzed. Compared with old DOPS, the use of the new DOPS was associated with greater utilization of the lowest score (2.4 % vs. 0.9 %; P < 0.001), broader range of scores, and a reduction in competent scores (60.8 % vs. 86.9 %; P < 0.001). The reduction in competent scores was evident on subgroup analysis across all procedure types (P < 0.001) and for each quartile of endoscopy experience. The new DOPS was superior in characterizing the endoscopy learning curve by demonstrating progression of competent scores across quartiles of procedural experience. CONCLUSIONS: Endoscopy assessors applied a greater range of scores using the new DOPS scale based on degree of supervision in two cohorts of trainees matched for experience. Our study provides construct validity evidence in support of the new scale format.

Colonoscopy Surveillance After Colorectal Cancer Resection: Recommendations of the US Multi-Society Task Force on Colorectal Cancer.

The US Multi-Society Task Force has developed updated recommendations to guide health care providers with the surveillance of patients after colorectal cancer (CRC) resection with curative intent. This document is based on a critical review of the literature regarding the role of colonoscopy, flexible sigmoidoscopy, endoscopic ultrasound, fecal testing and CT colonography in this setting. The document addresses the effect of surveillance, with focus on colonoscopy, on patient survival after CRC resection, the appropriate use and timing of colonoscopy for perioperative clearing and for postoperative prevention of metachronous CRC, specific considerations for the detection of local recurrence in the case of rectal cancer, as well as the place of CT colonography and fecal tests in post-CRC surveillance.

[International status colorectal cancer screening and quality assurance of screening-colonoscopy]. / Internationaler Status Dickdarmkrebs-Screening und Qualitätssicherung der Screening-Koloskopie.

Bowel cancer is frequent, early stages have much better prognosis and drug treatment of late stages is increasingly very expensive. Screening for colorectal cancer has the potential for both early detection and prevention. For a screening intervention colonoscopy is very invasive and holds the small risk of serious complications. Colonoscopy plays a key role for further diagnosis and intervention in all programs. Current international screening activities are presented. The emerging evidence on effectiveness of screening suggests that all strategies may have similar effect sizes. Participation rates and quality assurance thus are of key importance for realizing potential net health gains. Participation rates are higher for stool tests than for sigmoidoscopy and colonoscopy. For quality assurance of screening-colonoscopy an established range of quality measures is available. The possibility of systematic quality assurance also in the context of opportunistic screening like in Austria is proven by Germany and Poland.

European guidelines for quality assurance in colorectal cancer screening and diagnosis. First Edition--Quality assurance in endoscopy in colorectal cancer screening and diagnosis.

Multidisciplinary, evidence-based guidelines for quality assurance in colorectal cancer screening and diagnosis have been developed by experts in a project coordinated by the International Agency for Research on Cancer. The full guideline document covers the entire process of population-based screening. It consists of 10 chapters and over 250 recommendations, graded according to the strength of the recommendation and the supporting evidence. The 450-page guidelines and the extensive evidence base have been published by the European Commission. The chapter on quality assurance in endoscopy includes 50 graded recommendations. The content of the chapter is presented here to promote international discussion and collaboration by making the principles and standards recommended in the new EU Guidelines known to a wider professional and scientific community. Following these recommendations has the potential to enhance the control of colorectal cancer through improvement in the quality and effectiveness of endoscopy and other elements in the screening process, including multidisciplinary diagnosis and management of the disease.

Longitudinal adherence to fecal occult blood testing impacts colorectal cancer screening quality.

OBJECTIVES: Existing cross-sectional quality measures for colorectal cancer (CRC) screening do not assess longitudinal adherence and thus may overestimate the quality of care. Our goal was to evaluate the adherence to repeated yearly fecal occult blood tests (FOBTs) in order to better understand the extent to which longitudinal adherence may impact screening quality. METHODS: This was a retrospective cohort analysis of 1,122,645 patients aged 50-75 years seen at any of the 136 Department of Veterans Affairs medical centers across the United States in 2000 and followed through 2005. The primary outcome was receipt of adequate CRC screening as defined by receipt of FOBTs in at least 4 out of 5 years or receipt of any number of FOBTs in addition to at least one colonoscopy, flexible sigmoidoscopy, or double-contrast barium enema. In a predefined subset of patients receiving exclusively FOBT, adherence with repeated testing was determined over the 5-year study period. RESULTS: Only 41.1% of men and 43.6% of women received adequate screening. Of the 384,527 men who received exclusively FOBT, 42.1% received a single FOBT, 26.0% received 2 tests, 17.8% received 3 tests, and only 14.1% were documented to have received at least 4 tests during the study period. Among the 10,469 female veterans receiving FOBT alone, rates were similar with only 13.7% completing at least 4 FOBTs in the 5-year study period. CONCLUSIONS: Adherence to repeated FOBT is low, suggesting that cross-sectional measurements of quality may overestimate the programmatic success of CRC screening.

Are physicians' recommendations for colorectal cancer screening guideline-consistent?

BACKGROUND: Many older adults in the U.S. do not receive appropriate colorectal cancer (CRC) screening. Although primary care physicians' recommendations to their patients are central to the screening process, little information is available about their recommendations in relation to guidelines for the menu of CRC screening modalities, including fecal occult blood testing (FOBT), flexible sigmoidoscopy (FS), colonoscopy, and double contrast barium enema (DCBE). The objective of this study was to explore potentially modifiable physician and practice factors associated with guideline-consistent recommendations for the menu of CRC screening modalities. METHODS: We examined data from a nationally representative sample of 1266 physicians in the U.S. surveyed in 2007. The survey included questions about physician and practice characteristics, perceptions about screening, and recommendations for age of initiation and screening interval for FOBT, FS, colonoscopy and DCBE in average risk adults. Physicians' screening recommendations were classified as guideline consistent for all, some, or none of the CRC screening modalities recommended. Analyses used descriptive statistics and polytomous logit regression models. RESULTS: Few (19.1%; 95% CI:16.9%, 21.5%) physicians made guideline-consistent recommendations across all CRC screening modalities that they recommended. In multivariate analysis, younger physician age, board certification, north central geographic region, single specialty or multi-specialty practice type, fewer patients per week, higher number of recommended modalities, use of electronic medical records, greater influence of patient preferences for screening, and published clinical evidence were associated with guideline-consistent screening recommendations (p < 0.05). CONCLUSIONS: Physicians' CRC screening recommendations reflect both overuse and underuse, and few made guideline-consistent CRC screening recommendations across all modalities they recommended. Interventions that focus on potentially modifiable physician and practice factors that influence overuse and underuse and address the menu of recommended screening modalities will be important for improving screening practice.

Timing of recurrences of TEM resected rectal neoplasms is variable as per the surveillance practices of one tertiary care institution.

Transanal endoscopic microsurgery (TEM) is widely used for the excision of rectal adenomas and early rectal adenocarcinoma. Few recommendations currently exist for surveillance of lesions excised by TEM. The purpose of this study was to review the surveillance practices and the patterns of recurrence among TEM resected lesions at a tertiary care hospital. A retrospective chart review was performed on all patients who underwent TEM for rectal adenoma or adenocarcinoma before June 2017. In our study population of 114 patients, the final pathology included 78 (68%) adenomas and 36 (32%) adenocarcinomas. Of the adenocarcinomas 23, 9, and 4 were T1, T2, T3 lesions, respectively. Of those, 25 patients opted for surveillance instead of further treatment. The most commonly recommended endoscopic surveillance strategy by our group for both adenomas and adenocarcinomas excised by TEM was flexible sigmoidoscopy every 6 months for 2 years. Recurrences occurred in 4/78 (5.1%) adenoma patients, all found within 16.9 months of surgery, and in 4/25 (16%) adenocarcinoma patients, found between 7.4 and 38.5 months post-surgery. Our data highlights the fact that the timing of recurrences post TEM surgery is variable. Further studies looking at recurrence patterns are needed in order to create comprehensive guidelines for surveillance of these patients.

Population-based prevalence estimates of history of colonoscopy or sigmoidoscopy: review and analysis of recent trends.

BACKGROUND: Lower GI endoscopy, such as colonoscopy or sigmoidoscopy, is thought to have a substantial impact on colorectal cancer incidence and mortality through detection and removal of precancerous lesions and early cancers. We aimed to review prevalence estimates of history of colonoscopy or sigmoidoscopy in the general population and to analyze recent trends. METHODS: A systematic review of the medical literature, including MEDLINE (1966 to August 2008) and EMBASE (1980 to August 2008), was undertaken, supplemented by searches of the European Health Interview & Health Examination Surveys database and bibliographies. Detailed age-specific and sex-specific prevalence estimates from the United States were obtained from the Behavioral Risk Factor Surveillance System surveys 2002, 2004, and 2006. RESULTS: The search yielded 55 studies that met our inclusion criteria. The majority of the reports (43) originated from the United States. Other countries of origin included Australia (2), Austria (2), Canada (5), France (1), Germany (1), and Greece (1). Estimates from the United States were generally increasing over time up to 56% (2006) for lifetime use of colonoscopy or sigmoidoscopy in people aged 50 years and older. Analysis of national survey data showed higher prevalences among men aged 55 years and older than for women of the same age. Prevalences were highest for people aged 70 to 79 years. CONCLUSION: Data from outside the United States were extremely limited. Prevalence estimates from the United States indicate that a considerable and increasing proportion of the population at risk has had at least 1 colonoscopy or sigmoidoscopy in their lives, although differences between age and sex groups persist. Prevalences of previous colonoscopy or sigmoidoscopy need to be taken into account in the interpretation of time trends in, and variation across, populations of colorectal cancer incidence and mortality.

The role of routine flexible sigmoidoscopy in patients presenting with fistula-in-ano: an observational study.

OBJECTIVE: Flexible sigmoidoscopy is useful to look for an underlying aetiology in fistula-in-ano. This study was aimed to assess the yield of routine flexible sigmoidoscopy in patients presenting with fistula-in-ano. A retrospective analysis of 159 consecutive patients with fistula-in-ano who underwent routine flexible sigmoidoscopy was performed. Sigmoidoscopy findings were recorded on a standard uniform format using a computer database. Those with a known aetiology were excluded. RESULTS: The median age was 39 (range: 14-74) years and the majority were males (n = 128, 80.5%). Forty-nine patients (30.8%) presented with a recurrent fistula-in-ano. On flexible sigmoidoscopy, internal opening was seen in only 23 patients (14.4%). Furthermore, incidental findings of haemorrhoids (n = 5, 3.1%) and polyps (n = 7, 4.4%) were found. One patient (0.6%) had a healed anal fissure, 5 patients (3.1%) had inflamed mucosa and 2 patients (1.3%) had ulcers. Only two patients with inflamed mucosa were diagnosed to have Crohn's disease on histology. Therefore, flexible sigmoidoscopy was not helpful in the majority to locate the internal opening. Only two patients had evidence of an underlying aetiology, which was Crohn's disease. However, they had recurrent complex fistulae and other associated symptoms. Therefore, flexible sigmoidoscopy may be reserved for selected group of patients with symptoms of an underlying aetiology.

Computed tomography versus lower endoscopy as initial diagnostic method for evaluating patients with hematochezia at emergency room.

For acute lower gastrointestinal bleeding (LGIB), lower gastrointestinal endoscopy is the preferred initial diagnostic test. However, it is difficult to perform urgently. Computed tomography (CT) is a convenient alternative.This study aimed to determine the diagnostic performance of CT compared to lower endoscopy as an initial test for evaluating acute LGIB.The medical records of 382 patients who visited our emergency department with hematochezia between January 2012 and January 2017 were retrospectively analyzed. Of them, 112 underwent CT, 65 underwent colonoscopy, and 205 underwent sigmoidoscopy as an initial test. For each method, sensitivity, specificity, positive predictive value, and negative predictive value were calculated upon active bleeding site detection and LGIB etiology diagnosis.The sensitivity, specificity, positive predictive value, and negative predictive value of CT for active bleeding site detection were 85.7%, 100%, 100%, and 96.9%, respectively, while those for identifying the etiology of LGIB were 87.4%, 40.0%, 83.5, and 47.6%, respectively.CT was not inferior to lower endoscopy for active bleeding site detection. Early localization and the exclusion of active bleeding were possible with CT. Etiology was diagnosed with high sensitivity and PPV by CT. Thus, CT can be an alternative initial diagnostic tool for evaluating acute LGIB.

Cumulative incidence of false-positive results in repeated, multimodal cancer screening.

PURPOSE: Multiple cancer screening tests have been advocated for the general population; however, clinicians and patients are not always well-informed of screening burdens. We sought to determine the cumulative risk of a false-positive screening result and the resulting risk of a diagnostic procedure for an individual participating in a multimodal cancer screening program. METHODS: Data were analyzed from the intervention arm of the ongoing Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial, a randomized controlled trial to determine the effects of prostate, lung, colorectal, and ovarian cancer screening on disease-specific mortality. The 68,436 participants, aged 55 to 74 years, were randomized to screening or usual care. Women received serial serum tests to detect cancer antigen 125 (CA-125), transvaginal sonograms, posteroanterior-view chest radiographs, and flexible sigmoidoscopies. Men received serial chest radiographs, flexible sigmoidoscopies, digital rectal examinations, and serum prostate-specific antigen tests. Fourteen screening examinations for each sex were possible during the 3-year screening period. RESULTS: After 14 tests, the cumulative risk of having at least 1 false-positive screening test is 60.4% (95% CI, 59.8%-61.0%) for men, and 48.8% (95% CI, 48.1%-49.4%) for women. The cumulative risk after 14 tests of undergoing an invasive diagnostic procedure prompted by a false-positive test is 28.5% (CI, 27.8%-29.3%) for men and 22.1% (95% CI, 21.4%-22.7%) for women. CONCLUSIONS: For an individual in a multimodal cancer screening trial, the risk of a false-positive finding is about 50% or greater by the 14th test. Physicians should educate patients about the likelihood of false positives and resulting diagnostic interventions when counseling about cancer screening.

Colorectal cancer screening with faecal immunochemical testing, sigmoidoscopy or colonoscopy: a clinical practice guideline.

CLINICAL QUESTION: Recent 15-year updates of sigmoidoscopy screening trials provide new evidence on the effectiveness of colorectal cancer screening. Prompted by the new evidence, we asked: "Does colorectal cancer screening make an important difference to health outcomes in individuals initiating screening at age 50 to 79? And which screening option is best?" CURRENT PRACTICE: Numerous guidelines recommend screening, but vary on recommended test, age and screening frequency. This guideline looks at the evidence and makes recommendations on screening for four screening options: faecal immunochemical test (FIT) every year, FIT every two years, a single sigmoidoscopy, or a single colonoscopy. RECOMMENDATIONS: These recommendations apply to adults aged 50-79 years with no prior screening, no symptoms of colorectal cancer, and a life expectancy of at least 15 years. For individuals with an estimated 15-year colorectal cancer risk below 3%, we suggest no screening (weak recommendation). For individuals with an estimated 15-year risk above 3%, we suggest screening with one of the four screening options: FIT every year, FIT every two years, a single sigmoidoscopy, or a single colonoscopy (weak recommendation). With our guidance we publish the linked research, a graphic of the absolute harms and benefits, a clear description of how we reached our value judgments, and linked decision aids. HOW THIS GUIDELINE WAS CREATED: A guideline panel including patients, clinicians, content experts and methodologists produced these recommendations using GRADE and in adherence with standards for trustworthy guidelines. A linked systematic review of colorectal cancer screening trials and microsimulation modelling were performed to inform the panel of 15-year screening benefits and harms. The panel also reviewed each screening option's practical issues and burdens. Based on their own experience, the panel estimated the magnitude of benefit typical members of the population would value to opt for screening and used the benefit thresholds to inform their recommendations. THE EVIDENCE: Overall there was substantial uncertainty (low certainty evidence) regarding the 15-year benefits, burdens and harms of screening. Best estimates suggested that all four screening options resulted in similar colorectal cancer mortality reductions. FIT every two years may have little or no effect on cancer incidence over 15 years, while FIT every year, sigmoidoscopy, and colonoscopy may reduce cancer incidence, although for FIT the incidence reduction is small compared with sigmoidoscopy and colonoscopy. Screening related serious gastrointestinal and cardiovascular adverse events are rare. The magnitude of the benefits is dependent on the individual risk, while harms and burdens are less strongly associated with cancer risk. UNDERSTANDING THE RECOMMENDATION: Based on benefits, harms, and burdens of screening, the panel inferred that most informed individuals with a 15-year risk of colorectal cancer of 3% or higher are likely to choose screening, and most individuals with a risk of below 3% are likely to decline screening. Given varying values and preferences, optimal care will require shared decision making.

Factors affecting adenoma detection rate in a national flexible sigmoidoscopy screening programme: a retrospective analysis.

BACKGROUND: A national colorectal cancer screening programme started in England in 2013, offering one-off flexible sigmoidoscopy to all men and women aged 55 years in addition to the biennial faecal occult blood testing programme offered to all individuals aged 60-74 years. We analysed data from six pilot flexible sigmoidoscopy screening centres to examine factors affecting the adenoma detection rate (ADR). METHODS: We did a retrospective analysis of flexible sigmoidoscopy screening procedures performed in individuals aged 55 years at six pilot sites in England as part of the National Health Service Bowel Scope Screening programme. ADR (number of procedures in which at least one adenoma was removed or biopsied, divided by total number of procedures) was calculated for each site and each endoscopist. Multiple regression models were used to examine the variation in ADR with withdrawal time and extent of examination, and the effect of other factors including comfort and bowel preparation on extent of examination. FINDINGS: The analysis included 8256 procedures done between May 7, 2013, and May 6, 2014. The overall ADR was 9·1% (95% CI 8·5-9·8; 755 of 8256 procedures), varying from 7·4% (6·2-8·9) to 11·0% (9·1-13·4) by screening centre. The ADR was 11·5% (95% CI 10·6-12·5; 493 of 4299 procedures) in men and 6·6% (5·9-7·4; 262 of 3957 procedures) in women (p<0·0001). On multivariate analysis, factors associated with adenoma detection were male sex (relative risk 1·69, 95% CI 1·46-1·95; p<0·0001) and a withdrawal time from the splenic flexure of at least 3·25 min in negative procedures (1·22, 1·00-1·48; p=0·045). However, increasing the withdrawal time to 4·0 min or more did not increase the likelihood of adenoma detection (1·22, 0·99-1·51; p=0·057). Procedures not reaching the splenic flexure were associated with lower chance of adenoma detection (eg, 0·77, 0·66-0·91; p=0·0015 for procedures reaching the descending colon), but there was no additional benefit associated with reaching the transverse colon (0·83, 0·67-1·02; p=0·069). Women (0·83, 0·80-0·87; p<0·0001), individuals with adequate (0·79, 0·76-0·83; p<0·0001) or poor (0·58, 0·51-0·67; p<0·0001) bowel preparation (compared with good bowel preparation), and those with mild (0·82, 0·76-0·88; p<0·0001) or moderate or severe (0·58, 0·51-0·66; p<0·0001) discomfort (compared with no discomfort) were less likely to have a procedure reaching the splenic flexure. INTERPRETATION: Key performance indicators for flexible sigmoidoscopy screening should be defined, including standards for insertion and withdrawal times, optimal depth, and bowel preparation. ADR could be improved by recommending a withdrawal time from the splenic flexure of at least 3·25 min (ideally 3·5-4·0 min). FUNDING: None.

Effectiveness of sigmoidoscopy for assessing ulcerative colitis disease activity and therapeutic response.

Ulcerative colitis (UC) typically begins in the rectum and progresses proximally in a contiguous fashion without skip lesions. Post-treatment inflammation distribution can change over time. Colonoscopy is unpleasant for the patient and clinical trials often use sigmoidoscopy for evaluation of disease severity. The aim of this study is to evaluate whether sigmoidoscopy is adequate to assess disease activity and therapeutic response as colonoscopy.We retrospectively reviewed patients who underwent colonoscopy for the initial diagnosis and follow-up by evaluating their mucosal inflammation in our hospital from January 2012 and December 2017.A total of 69 patients were analyzed. During follow up, the inflamed segment changed post-treatment in 62% (43/69). Extensive UC was common in the changed disease extent group (P < .01). Patients treated with oral mesalazine had a higher rate of changed disease extent (P < .01). The sigmoid segment was the most commonly involved segment, and the rectum was the severely inflamed segment during initial diagnosis and follow-up. According to Mayo endoscopic subscore (MES) in the most severely inflamed colonic and rectosigmoid segment, there were high degrees of correlation in the initial UC diagnosis (r = .90, P < .01) and follow-up (r = .74, P < .01).Our findings suggest that sigmoidoscopy is effective as colonoscopy for detecting disease activity and evaluating therapeutic response in UC patients during follow-up.

Colorectal cancer screening with faecal immunochemical testing, sigmoidoscopy or colonoscopy: a microsimulation modelling study.

OBJECTIVE: To estimate benefits and harms of different colorectal cancer screening strategies, stratified by (baseline) 15-year colorectal cancer risk. DESIGN: Microsimulation modelling study using MIcrosimulation SCreening ANalysis-Colon (MISCAN-Colon). SETTING: A parallel guideline committee (BMJ Rapid Recommendations) defined the time frame and screening interventions, including selection of outcome measures. POPULATION: Norwegian men and women aged 50-79 years with varying 15-year colorectal cancer risk (1-7%). COMPARISONS: Four screening strategies were compared with no screening: biennial or annual faecal immunochemical test (FIT) or single sigmoidoscopy or colonoscopy at 100% adherence. MAIN OUTCOME MEASURES: Colorectal cancer mortality and incidence, burdens, and harms over 15 years of follow-up. The certainty of the evidence was assessed using the GRADE approach. RESULTS: Over 15 years of follow-up, screening individuals aged 50-79 at 3% risk of colorectal cancer with annual FIT or single colonoscopy reduced colorectal cancer mortality by 6 per 1000 individuals. Single sigmoidoscopy and biennial FIT reduced it by 5 per 1000 individuals. Colonoscopy, sigmoidoscopy, and annual FIT reduced colorectal cancer incidence by 10, 8, and 4 per 1000 individuals, respectively. The estimated incidence reduction for biennial FIT was 1 per 1000 individuals. Serious harms were estimated to be between 3 per 1000 (biennial FIT) and 5 per 1000 individuals (colonoscopy); harms increased with older age. The absolute benefits of screening increased with increasing colorectal cancer risk, while harms were less affected by baseline risk. Results were sensitive to the setting defined by the guideline panel. Because of uncertainty associated with modelling assumptions, we applied a GRADE rating of low certainty evidence to all estimates. CONCLUSIONS: Over a 15 year period, all screening strategies may reduce colorectal cancer mortality to a similar extent. Colonoscopy and sigmoidoscopy may also reduce colorectal cancer incidence, while FIT shows a smaller incidence reduction. Harms are rare and of similar magnitude for all screening strategies.