Prevalence and predictors of interval colorectal cancers in medicare beneficiaries

Association between Endoscopist Volume and Interval Cancers after Colonoscopy: Results from the National Colorectal Cancer Screening Program in Korea

PURPOSE

The rate of interval colorectal cancer (iCRC) is now accepted as a key performance indicator of organized colorectal cancer (CRC) screening programs. We aimed to examine the association between endoscopist volumes and the rate of iCRC among individuals with a positive fecal immunochemical test (FIT) within a nationwide population-based CRC screening program.

MATERIALS AND METHODS

Individuals aged ≥ 50 years who underwent colonoscopy after a positive FIT from January 1, 2019 until December 31, 2020 in the Korean National Cancer Screening Program (KNCSP) were enrolled. We converted the data into per-endoscopist screening results, calculated the iCRC rates per endoscopist, and compared them to the previous year's annual volume that was divided into five groups (V1, 1-9; V2, 10-29; V3, 30-59; V4, 60-119; V5, ≥ 120).

RESULTS

A total of 10,412 endoscopists performed 216,907 colonoscopies. Overall, the average rate of iCRC per endoscopist was 8.46 per 1,000 examinations. Compared with the group with the highest volume (V5 group), the rate of iCRC was 2.21 times higher in the V1 group. Similar trends were observed in the other groups (V2: relative risks [RR], 2.15; 95% confidence interval [CI], 1.57 to 2.94; V3: RR, 1.56; 95% CI, 1.15 to 2.13; V4: RR, 1.18; 95% CI, 0.83 to 1.67).

CONCLUSION

The findings emphasize that endoscopists with lower procedure volumes have higher risks of interval cancer being missed or undetected. To maximize the preventative impact of colonoscopy for CRC, this issue should be addressed by monitoring endoscopist volumes and variations in performances.

Polyp detection with colonoscopy assisted by the GI Genius artificial intelligence endoscopy module compared with standard colonoscopy in routine colonoscopy practice (COLO-DETECT): a multicentre, open-label, parallel-arm, pragmatic randomised controlled trial

BACKGROUND

Increased polyp detection during colonoscopy is associated with decreased post-colonoscopy colorectal cancer incidence and mortality. The COLO-DETECT trial aimed to assess the clinical effectiveness of the GI Genius intelligent endoscopy module for polyp detection, comparing colonoscopy assisted by GI Genius (computer-aided detection [CADe]-assisted colonoscopy) with standard colonoscopy in routine practice.

METHODS

We did a multicentre, open-label, parallel-arm, pragmatic randomised controlled trial in 12 National Health Service (NHS) hospitals (ten NHS Trusts) in England, among adults (aged ≥18 years) undergoing planned colonoscopy for gastrointestinal symptoms or for surveillance due to personal or family history (ie, symptomatic indications), or colorectal cancer screening. Randomisation (1:1) to CADe-assisted colonoscopy or standard colonoscopy was done with a web-based dynamic adaptive algorithm, immediately before colonoscopy, with stratification by age group, sex, colonoscopy indication (screening or symptomatic), and NHS Trust. Recruiting staff, participants, and colonoscopists were unmasked to trial allocation; histopathologists, co-chief investigators, and trial statisticians were masked. CADe-assisted colonoscopy consisted of standard colonoscopy plus the GI Genius module active for at least the entire inspection phase of colonoscope withdrawal. The primary outcome was mean adenomas per procedure (total number of adenomas detected divided by total number of procedures); the key secondary outcome was adenoma detection rate (proportion of colonoscopies with at least one adenoma). Analysis was by intention to treat (ITT), with outcomes compared between groups by mixed-effects regression modelling, in which effect estimates were adjusted for randomisation stratification variables. Data were imputed for outcome measures with more than 5% missing values. All participants who underwent colonoscopy were assessed for safety. The trial is registered on ISRCTN (ISRCTN10451355) and ClinicalTrials.gov (NCT04723758), and is complete.

FINDINGS

Between March 29, 2021, and April 6, 2023, 2032 participants (1132 [55·7%] male, 900 [44·3%] female; mean age 62·4 years [SD 10·8]) were recruited and randomly assigned: 1015 to CADe-assisted colonoscopy and 1017 to standard colonoscopy. 1231 (60·6%) participants were undergoing screening and 801 (39·4%) had symptomatic indications. Mean adenomas per procedure was 1·56 (SD 2·82; n=1001 participants with available data) in the CADe-assisted colonoscopy group versus 1·21 (1·91; n=1009) in the standard colonoscopy group, representing an adjusted mean difference of 0·36 (95% CI 0·14-0·57; adjusted incidence rate ratio 1·30 [95% CI 1·15-1·47], p<0·0001). Adenomas were detected in 555 (56·6%) of 980 participants in the CADe-assisted colonoscopy group versus 477 (48·4%) of 986 in the standard colonoscopy group, representing a proportion difference of 8·3% (95% CI 3·9-12·7; adjusted odds ratio 1·47 [95% CI 1·21-1·78], p<0·0001). Numbers of adverse events were similar between the CADe-assisted colonoscopy and standard colonoscopy groups (adverse events: 25 vs 19; serious adverse events: four vs six), and no adverse events in the CADe-assisted colonoscopy group were deemed to be related to GI Genius use on independent review.

INTERPRETATION

Results of the COLO-DETECT trial support the use of GI Genius to increase detection of premalignant colorectal polyps in routine colonoscopy practice.

FUNDING

Medtronic.

Imaging colonic polyps in 2024

Screening colonoscopy and polypectomy are the cornerstone in decreasing the incidence and mortality of colorectal cancer. Despite the low incidence of colorectal cancer in India, there has been a rising trend in the incidence of colonic polyps and cancer over the last decade. It is, hence, imperative that we are well equipped in the management of colonic polyps. Adequate training in the detection and characterization of polyps to aid in their management is necessary. Detection of polyps can be increased by adhering to the standards of colonoscopy, including good bowel preparation, cecal intubation rate, adequate withdrawal time and use of distal attachment devices. A detected polyp needs optimal characterization to predict histology in real time and decide on the management strategies. Characterization of the polyps requires high-definition-white light endoscopy and/or image-enhanced endoscopy (dye based or digital). Various factors that help in predicting histology include size, location and morphology of the polyp and the pit pattern, vascular and surface pattern of the polyp. Polyps can be differentiated as neoplastic or non-neoplastic with reasonable accuracy with the above features. Prediction of advanced pathology including high-grade dysplasia and deep sub-mucosal invasion is essential, as it helps in deciding if the lesion is amenable to endotherapy and the technique of endoscopic resection. Adequate training in image-enhanced endoscopy is necessary to assess advanced pathology in polyps. Technology pertaining to image-enhanced endoscopy includes narrow banding imaging and blue laser imaging; newer variations are being introduced every few years making it necessary to be abreast with growing information. The recent advances in gastrointestinal (GI) endoscopy with the advent of endocytoscopy and artificial intelligence seem promising and are predicted to be the future of GI endoscopy.

Esophageal cancers missed at upper endoscopy in Central Norway 2004 to 2021 - A population-based study

INTRODUCTION

The incidence of esophageal cancers is increasing in many Western countries and the rate of missed esophageal cancers (MEC) at upper endoscopy is of concern. We aimed to calculate the MEC rate and identify factors associated with MEC.

METHODS

This was a retrospective population-based cohort study including 613 patients diagnosed with esophageal cancer in Central Norway 2004-2021. MEC was defined as esophageal cancer diagnosed 6-36 months after a non-diagnostic upper endoscopy. Patient characteristics, tumor localization, histological type and cTNM stage were recorded. Symptoms, endoscopic findings, use of sedation and endoscopists experience at the endoscopy prior to esophageal cancer diagnosis and at the time of diagnosis were recorded. The association between these factors and MEC was assessed.

RESULTS

Forty-nine (8.0%) of 613 cancers were MEC. There was a significant increase in annual numbers of esophageal cancer (p < 0.001) as well as of MEC (p = 0.009), but MEC rate did not change significantly (p = 0.382). The median time from prior upper endoscopy to MEC diagnosis was 22.9 (12.1-28.6) months. MEC patients were older and were diagnosed with disease with a lower cTNM stage and cT category than non-missed cancers, whereas tumor localization and histological type were similar between the groups. The use of sedation or endoscopist experience did not differ between the endoscopy prior to esophageal cancer diagnosis and at the time of diagnosis. High proportions of MEC patients had Barrett's esophagus (n = 25, 51.0%), hiatus hernia (n = 26, 53.1%), esophagitis (n = 10, 20.4%) or ulceration (n = 4, 8.2%). Significant proportions of MECs were diagnosed after inappropriate follow-up of endoscopic Barrett's esophagus, histological dysplasia or ulcerations.

CONCLUSIONS

The annual number of MEC increased during the study period, while the MEC rate remained unchanged. Endoscopic findings related to gastroesophageal reflux disease such as esophagitis and Barrett's esophagus were identified in a high proportion of patients with subsequent MECs. Cautious follow-up of these patients could potentially reduce MEC-rate.

Will artificial intelligence reach any limit in gastroenterology?

Endoscopy is the cornerstone in the management of digestive diseases. Over the last few decades, technology has played an important role in the development of this field, helping endoscopists in better detecting and characterizing luminal lesions. However, despite ongoing advancements in endoscopic technology, the incidence of missed pre-neoplastic and neoplastic lesions remains high due to the operator-dependent nature of endoscopy and the challenging learning curve associated with new technologies. Artificial intelligence (AI), an operator-independent field, could be an invaluable solution. AI can serve as a “second observer”, enhancing the performance of endoscopists in detecting and characterizing luminal lesions. By utilizing deep learning (DL), an innovation within machine learning, AI automatically extracts input features from targeted endoscopic images. DL encompasses both computer-aided detection and computer-aided diagnosis, assisting endoscopists in reducing missed detection rates and predicting the histology of luminal digestive lesions. AI applications in clinical gastrointestinal diseases are continuously expanding and evolving the entire digestive tract. In all published studies, real-time AI assists endoscopists in improving the performance of non-expert gastroenterologists, bringing it to a level comparable to that of experts. The development of DL may be affected by selection biases. Studies have utilized different AI-assisted models, which are heterogeneous. In the future, algorithms need validation through large, randomized trials. Theoretically, AI has no limit to assist endoscopists in increasing the accuracy and the quality of endoscopic exams. However, practically, we still have a long way to go before standardizing our AI models to be accepted and applied by all gastroenterologists.

Usefulness of magnifying endoscopy for diagnosis of sessile serrated lesion with dysplasia or carcinoma: Large retrospective study

Background and study aims Sessile serrated lesions (SSLs) are precursor lesions in the serrated neoplasia pathway that lead to invasive carcinoma from dysplasia arising from SSLs. This study aimed to elucidate the clinicopathological and endoscopic features of SSLs with and without dysplasia or carcinoma. Patients and methods We reviewed the clinicopathological and endoscopic data from all colorectal lesions pathologically diagnosed as SSLs at Juntendo University Hospital, Tokyo, Japan, between 2011 and 2022. In addition to conventional endoscopic findings, we retrospectively evaluated magnifying endoscopic findings with narrow-band imaging (NBI) or blue laser imaging (BLI) using the Japan NBI Expert Team system and analyzed pit patterns using magnified chromoendoscopic images. Results Of the 2,132 SSLs, 92.5%, 4.7%, 1.8%, and 0.9% had no dysplasia, low-grade dysplasia, high-grade dysplasia, and submucosal invasive carcinoma, respectively. Older age, the proximal colon, and larger lesions were more frequently associated with SSLs with dysplasia or carcinoma. However, 41.3% of the SSLs with dysplasia or carcinoma were ≤ 10 mm in size. Endoscopic findings, such as (semi)pedunculated morphology, double elevation, central depression, and reddishness, were frequently found in SSLs with dysplasia or carcinoma. Furthermore, magnifying endoscopy using NBI or BLI and magnifying chromoendoscopy showed high sensitivity, specificity, and accuracy for diagnosing dysplasia or carcinoma within SSLs. Conclusions SSLs with and without dysplasia or carcinoma exhibit distinct clinicopathological and endoscopic features. In an SSL series, conventional endoscopic characteristics in addition to use of magnifying endoscopy may be useful for accurately diagnosing advanced histology within an SSL.

Type 2 diabetes mellitus and post-colonoscopy colorectal cancer: clinical and molecular characteristics and survival

PURPOSE

Studies suggest that patients with type two diabetes mellitus (T2D) may be at increased risk of post-colonoscopy colorectal cancer (PCCRC). We investigated clinical and molecular characteristics and survival of T2D patients with PCCRC to elucidate how T2D-related PCCRC may arise.

METHODS

We identified T2D patients with colorectal cancer (CRC) from 1995 to 2015 and computed prevalence ratios (PRs) comparing clinical and molecular characteristics of CRC in T2D patients with PCCRC vs. in T2D patients with colonoscopy-detected CRC (dCRC). We also followed T2D patients from the diagnosis of PCCRC/dCRC until death, emigration, or study end and compared mortality using Cox-proportional hazards regression models adjusted for sex, age, year of CRC diagnosis, and CRC stage.

RESULTS

Compared with dCRC, PCCRC was associated with a higher prevalence of proximal CRCs (54% vs. 40%; PR: 1.43, 95% confidence interval [CI] 1.27-1.62) in T2D patients. We found no difference between PCCRC vs. dCRC for CRC stage, histology, and mismatch repair status. The proportion of CRCs that could be categorized as PCCRC decreased over time. Within one year after CRC, 63% of PCCRC vs. 78% of dCRC patients were alive (hazard ratio [HR] 1.85 [95% CI 1.47-2.31]). Within five years after CRC, 44% of PCCRC vs. 54% of dCRC patients were still alive (HR 1.44 [95% CI 1.11-1.87]).

CONCLUSION

The increased prevalence of proximally located PCCRCs and the poorer survival may suggest overlooked colorectal lesions as a predominant explanation for T2D-related PCCRC, although altered tumor progression cannot be ruled out.

Big data approach in the field of gastric and colorectal cancer research

Big data is characterized by three attributes: volume, variety,, and velocity. In healthcare setting, big data refers to vast dataset that is electronically stored and managed in an automated manner and has the potential to enhance human health and healthcare system. In this review, gastric cancer (GC) and postcolonoscopy colorectal cancer (PCCRC) will be used to illustrate application of big data approach in the field of gastrointestinal cancer research. Helicobacter pylori (HP) eradication only reduces GC risk by 46% due to preexisting precancerous lesions. Apart from endoscopy surveillance, identifying medications that modify GC risk is another strategy. Population-based cohort studies showed that long-term use of proton pump inhibitors (PPIs) associated with higher GC risk after HP eradication, while aspirin and statins associated with lower risk. While diabetes mellitus conferred 73% higher GC risk, metformin use associated with 51% lower risk, effect of which was independent of glycemic control. Nonetheless, nonsteroidal anti-inflammatory drugs (NA-NSAIDs) are not associated with lower GC risk. CRC can still occur after initial colonoscopy in which no cancer was detected (i.e. PCCRC). Between 2005 and 2013, the rate of interval-type PCCRC-3y (defined as CRC diagnosed between 6 and 36 months of index colonoscopy which was negative for CRC) was 7.9% in Hong Kong, with >80% being distal cancers and higher cancer-specific mortality compared with detected CRC. Certain clinical and endoscopy-related factors were associated with PCCRC-3 risk. Medications shown to have chemopreventive effects on PCCRC include statins, NA-NSAIDs, and angiotensin-converting enzyme inhibitors/angiotensin receptor blockers.

Clinical and endoscopic characteristics and management of 220 cases with serrated polyps

BACKGROUND

Serrated polyps are considered the precursor lesions of colorectal cancer through the serrated pathway. In the present study, we aimed to evaluate and discuss the clinical and endoscopic characteristics and management of serrated polyps.

METHODS

The data of 220 cases with serrated polyps between September 2018 and November 2021 in Shenzhen People's Hospital were retrospectively analyzed.

RESULTS

Of all these cases, 32 were hyperplastic polyps, 36 were traditional serrated adenomas, 126 were sessile serrated lesions, 25 were SSLs with dysplasia, and one was an unclassified serrated adenoma. Although most patients were males aged ≥50 years and most serrated polyps were located in the distal colon and rectum with a size of 6-10 mm and the shape of type 0-Is, there was no significant difference (P > 0.05). Serrated polyps of ≤5 mm in size and type 0-IIa were mostly removed by cold biopsy forceps. Cold snare polypectomy was primarily used for those of 6-10 mm in size. Endoscopic mucosal resection was used for those of 6-20 mm, and endoscopic submucosal dissection was used for those of ≥20 mm (P < 0.05). All complications occurred in SSL patients with or without dysplasia (P < 0.05).

CONCLUSIONS

Clinical and endoscopic characteristics were beneficial for distinguishing and diagnosing serrated polyps. In addition, management options were crucial to prevent recurrence and progression. However, the detection rate of serrated polyps was relatively low. Therefore, prospective multicenter studies with large samples are necessary to better assess colorectal serrated polyps.

AGA Clinical Practice Update on the Role of Artificial Intelligence in Colon Polyp Diagnosis and Management: Commentary

DESCRIPTION

The purpose of this American Gastroenterological Association (AGA) Institute Clinical Practice Update (CPU) is to review the available evidence and provide expert commentary on the current landscape of artificial intelligence in the evaluation and management of colorectal polyps.

METHODS

This CPU was commissioned and approved by the AGA Institute Clinical Practice Updates Committee (CPUC) and the AGA Governing Board to provide timely guidance on a topic of high clinical importance to the AGA membership and underwent internal peer review by the CPUC and external peer review through standard procedures of Gastroenterology. This Expert Commentary incorporates important as well as recently published studies in this field, and it reflects the experiences of the authors who are experienced endoscopists with expertise in the field of artificial intelligence and colorectal polyps.

Cost-Effectiveness of Liquid Biopsy for Colorectal Cancer Screening in Patients Who Are Unscreened

Importance

Despite recommendations for universal screening, adherence to colorectal cancer screening in the US is approximately 60%. Liquid biopsy tests are in development for cancer early detection, but it is unclear whether they are cost-effective for colorectal cancer screening.

Objective

To estimate the cost-effectiveness of liquid biopsy for colorectal cancer screening in the US.

Design, Setting, and Participants

In this economic evaluation, a Markov model was developed to compare no screening and 5 colorectal cancer screening strategies: colonoscopy, liquid biopsy, liquid biopsy following nonadherence to colonoscopy, stool DNA, and fecal immunochemical test. Adherence to first-line screening with colonoscopy, stool DNA, or fecal immunochemical test was assumed to be 60.6%, and adherence for liquid biopsy was assumed to be 100%. For colonoscopy, stool DNA, and fecal immunochemical test, patients who did not adhere to testing were not offered other screening. In colonoscopy-liquid biopsy hybrid, liquid biopsy was second-line screening for those who deferred colonoscopy. Scenario analyses were performed to include the possibility of polyp detection for liquid biopsy.

Exposures

No screening, colonoscopy, fecal immunochemical test, stool DNA, liquid biopsy, and colonoscopy-liquid biopsy hybrid screening.

Main Outcomes and Measures

Model outcomes included life expectancy, total cost, and incremental cost-effectiveness ratios. A strategy was considered cost-effective if it had an incremental cost-effectiveness ratio less than the US willingness-to-pay threshold of $100 000 per life-year gained.

Results

This study used a simulated cohort of patients aged 45 years with average risk of colorectal cancer. In the base case, colonoscopy was the preferred, or cost-effective, strategy with an incremental cost-effectiveness ratio of $28 071 per life-year gained. Colonoscopy-liquid biopsy hybrid had the greatest gain in life-years gained but had an incremental cost-effectiveness ratio of $377 538. Colonoscopy-liquid biopsy hybrid had a greater gain in life-years if liquid biopsy could detect polyps but remained too costly.

Conclusions and Relevance

In this economic evaluation of liquid biopsy for colorectal cancer screening, colonoscopy was a cost-effective strategy for colorectal cancer screening in the general population, and the inclusion of liquid biopsy as a first- or second-line screening strategy was not cost-effective at its current cost and screening performance. Liquid biopsy tests for colorectal cancer screening may become cost-effective if their cost is substantially lowered.

Postcolonoscopy Colorectal Cancer in a Referral Center for Colorectal Cancer: Prevalence and Risk Factors

Background and Aims

Colonoscopy is effective to detect and remove colorectal lesions. However, after a negative colonoscopy, cancers could be detected during the interval follow-up. This study was designed to identify characteristics and risk factors for postcolonoscopy colorectal cancer - interval type.

Methods

Medical records of individuals who were newly diagnosed with colorectal cancer between January 2018 and December 2019 were reviewed. Clinical, demographic, and endoscopic variables were analyzed. Those with the diagnosis of colorectal cancer between two consecutive colonoscopies performed within the appropriated surveillance range were considered to have postcolonoscopy colorectal cancer - interval type. A comparison between the group of patients with non-postcolonoscopy colorectal cancer - interval type and the group of patients with postcolonoscopy colorectal cancer - interval type was then performed.

Results

During the study period, 491 patients were newly diagnosed with colorectal cancer. Among them, 61 (12.4%) had postcolonoscopy colorectal cancer - interval subtype. Postcolonoscopy colorectal cancer - interval type was three times more prevalent on the proximal colon (p = 0.014) and was associated with the presence of two or more cardiovascular risk factors (aOR = 4.25; p = 0.016), cholecystectomy in the past (aOR = 10.09; p = 0.019), and family history of colorectal cancer on a first-degree relative (aOR = 4.25; p = 0.006). Moreover, isolated cardiovascular risk factors revealed a protective effect for the absence of all cardiovascular risk factors (aOR = 20; p = 0.034). The ROC curve associated with the multivariate model revealed a predictive power of 77.8% (p < 0.001).

Conclusions

Postcolonoscopy colorectal cancer - interval type is more common in the proximal colon and in patients with a family history (first-degree relative) of colorectal cancer, two or more cardiovascular risk factors, and a history of cholecystectomy. All of these are easily detectable in clinical practice and may be of extreme importance in the control of postcolonoscopy colorectal cancer in the near future.

Sessile serrated lesions with dysplasia: is it possible to nip them in the bud?

The serrated neoplasia pathway constitutes an "alternative route" to colorectal cancer (CRC), and sessile serrated lesions with dysplasia (SSLDs) are an intermediate step between sessile serrated lesions (SSLs) and invasive CRC in this pathway. While SSLs show indolent growth before becoming dysplastic (> 10-15 years), SSLDs are considered to rapidly progress to either immunogenic microsatellite instable-high (MSI-H) CRC (presumably 75% of cases) or mesenchymal microsatellite stable (MSS) CRC. Their flat shapes and the relatively short window of this intermediate state make it difficult to detect and diagnose SSLDs; thus, these lesions are potent precursors of post-colonoscopy/interval cancers. Confusing terminology and the lack of longitudinal observation data of serrated polyps have hampered the accumulation of knowledge about SSLDs; however, a growing body of evidence has started to clarify their characteristics and biology. Together with recent efforts to incorporate terminology, histological studies of SSLDs have identified distinct dysplastic patterns and revealed alterations in the tumor microenvironment (TME). Molecular studies at the single-cell level have identified distinct gene alterations in both the epithelium and the TME. Mouse serrated tumor models have demonstrated the importance of TME in disease progression. Advances in colonoscopy provide clues to distinguish pre-malignant from non-malignant-SSLs. Recent progress in all aspects of the field has enhanced our understanding of the biology of SSLDs. The aim of this review article was to assess the current knowledge of SSLDs and highlight their clinical implications.

The impact of surgical weight loss procedures on the risk of metachronous colorectal neoplasia: the differential effect of surgery type, sex, and anatomic location

Patients with prior colorectal polyps are at high risk for metachronous colorectal neoplasia, especially in the presence of obesity. We assessed the impact of 2 common bariatric surgeries, vertical sleeve gastrectomy and roux-n-Y gastric bypass, on the risk of colorectal neoplasia recurrence. This nationally representative analysis included 1183 postbariatric adults and 3193 propensity score-matched controls, who all had prior colonoscopy with polyps and polypectomy. Colorectal polyps reoccurred in 63.8% of bariatric surgery patients and 71.7% of controls at a mean follow-up of 53.1 months from prior colonoscopy. There was a reduced odds of colorectal polyp recurrence after bariatric surgery compared with controls (odds ratio [OR] = 0.70, 95% confidence interval [CI] = 0.58 to 0.83). This effect was most pronounced in men (OR = 0.58, 95% CI = 0.42 to 0.79), and post roux-n-Y gastric bypass (OR = 0.57, 95% CI = 0.41 to 0.79). However, the risk of rectal polyps or colorectal cancer remained consistent between groups. This study is the first to our knowledge to show a reduction in risk of polyp recurrence following bariatric surgery.

Post-colonoscopy cancer rate at a tertiary referral hospital in Australia: A data linkage analysis

BACKGROUND AND AIM

Colorectal cancer (CRC) diagnosed following a cancer-negative colonoscopy is termed as post-colonoscopy CRC (PCCRC). The World Endoscopy Organization has recently standardized the definition of PCCRC-3Y (CRC developing within 3 years of a cancer-negative colonoscopy). In the present study, we sought to assess PCCRC-3Y rate, perform root-cause analyses, and identify factors associated with development of PCCRC at a tertiary referral hospital in Australia.

METHODS

All patients undergoing colonoscopy from 2011 to 2018 were matched to a population-based cancer register. PCCRC-3Y rate was assessed for years 2011-2015. All PCCRC cases that developed within 6-48 months after a cancer-negative colonoscopy underwent root-cause analyses. Descriptive statistics were used to summarize data.

RESULTS

Among 17 828 patients undergoing colonoscopy, 367 CRC cases were diagnosed during the study period. This included nine PCCRC cases, which developed at a median of 14 months (range 7-34 months) after cancer-negative colonoscopy. The PCCRC-3Y rate for years 2011-2015 was 2.16% (95% CI 0.91-5.15). All nine PCCRC cases were moderately or poorly differentiated adenocarcinomas; seven of nine were early-stage CRC (stages I and II) and six of nine probably represented missed lesions at index colonoscopy despite an apparently adequate examination. History of inflammatory bowel disease (IBD) (odds ratio [OR] 21.9, 95% confidence interval [CI] 4.6-103.7, P < 0.001) and diverticulosis (OR 5.4, 95% CI 1.4-20.5, P = 0.01) were significantly associated with development of missed CRC.

CONCLUSIONS

In our tertiary referral colonoscopy cohort, PCCRC-3Y rate was 2.16% (95% CI 0.91-5.15). IBD and diverticulosis were significantly associated with risk of PCCRC. The majority of PCCRC lesions were likely missed at index colonoscopy, despite an apparently adequate examination.

Incomplete resection rates of 4- to 20-mm non-pedunculated colorectal polyps when using wide-field cold snare resection with routine submucosal injection

Background and study aims  Incomplete resection of 4- to 20-mm colorectal polyps occur frequently (> 10 %), putting patients at risk for post-colonoscopy colorectal cancer. We hypothesized that routine use of wide-field cold snare resection with submucosal injection (CSP-SI) might reduce incomplete resection rates (IRRs). Patients and methods  Patients aged 45 to 80 years undergoing elective colonoscopies were enrolled in a prospective clinical study. All 4- to 20-mm non-pedunculated polyps were resected using CSP-SI. Post-polypectomy margin biopsies were obtained to determine IRRs through histopathology assessment. The primary outcome was IRR, defined as remnant polyp tissue found on margin biopsies. Secondary outcomes included technical success and complication rates. Results  A total of 429 patients (median age 65 years, 47.1 % female, adenoma detection rate 40 %) with 204 non-pedunculated colorectal polyps 4 to 20 mm removed using CSP-SI were included in the final analysis. CSP-SI was technical successful in 97.5 % (199/204) of cases (5 conversion to hot snare polypectomy). IRR for CSP-SI was 3.8 % (7/183) (95 % confidence interval [CI] 2.7 %-5.5 %). IRR was 1.6 % (2/129), 16 % (4/25), and 3.4 % (1/29) for adenomas, serrated lesions, and hyperplastic polyps respectively. IRR was 2.3 % (2/87), 6.3 % (4/64), 4.0 % (6/151), and 3.1 % (1/32) for polyps 4 to 5 mm, 6 to 9 mm, < 10 mm, and 10 to 20 mm, respectively. There were no CSP-SI-related serious adverse events. Conclusions  Use of CSP-SI results in lower IRRs compared to what has previously been reported in the literature for hot or cold snare polypectomy when not using wide-field cold snare resection with submucosal injection. CSP-SI showed an excellent safety and efficacy profile, however comparative studies to CSP without SI are required to confirm these results.

Can endoscopic follow-up after acute diverticulitis be rationalised?

BACKGROUND

Acute diverticulitis (AD) is a common cause of presentation to emergency surgical services. Follow-up with endoluminal investigation to exclude colorectal cancer (CRC) remains controversial. Guidelines are increasingly moving to a more restrictive follow-up based on severity of disease and age. The purpose of this observational study was to assess the prevalence of CRC in AD patients and the impact of follow-up on endoscopy services.

METHODS

Patients admitted with a diagnosis of AD over a 2-year period were reviewed. The proportion of patients undergoing endoscopic follow-up and the CRC detection rate were recorded. The potential impact of a more conservative approach to follow-up was evaluated.

RESULTS

There were 484 patients with AD presenting 546 times (M:F = 198:286; median age = 63 years). 80% of admissions were aged 50 or older. There were 43 emergency interventions in 39 patients (10 percutaneous drain; 33 surgery). The remainder were managed conservatively. 28 patients (5.1%) underwent colonic resection with cancer found in one specimen (3.6%). 287 patients underwent endoluminal follow-up with cancer diagnosed in 3 cases (1.0%). There was no significant difference in the prevalence of CRC between patients requiring emergency surgery and those managed conservatively, or between patients with complicated versus uncomplicated diverticulitis.

CONCLUSION

CRC masquerading as acute diverticulitis is rare. The incidence of neoplasia both at endoscopic follow-up and in patients requiring emergency intervention is low. Conservative follow-up strategies appear safe, but their effectiveness in reducing the burden on endoscopy services may be limited by current age-based recommendations. Restricting follow-up to those with complicated AD would reduce the number of patients requiring endoluminal investigation by 70%.

Feasibility of moxifloxacin and proflavine dual fluorescence imaging for detecting gastrointestinal neoplastic lesions: A prospective study

OBJECTIVES

High-contrast and high-resolution imaging techniques would enable real-time sensitive detection of the gastrointestinal lesions. This study aimed to investigate the feasibility of novel dual fluorescence imaging using moxifloxacin and proflavine in the detection of neoplastic lesions of the human gastrointestinal tract.

METHODS

Patients with the colonic and gastric neoplastic lesions were prospectively enrolled. The lesions were biopsied with forceps or endoscopically resected. Dual fluorescence imaging was performed by using custom axially swept wide-field fluorescence microscopy after topical moxifloxacin and proflavine instillation. Imaging results were compared with both confocal imaging with cell labeling and conventional histological examination.

RESULTS

Ten colonic samples (one normal mucosa, nine adenomas) from eight patients and six gastric samples (one normal mucosa, five adenomas) from four patients were evaluated. Dual fluorescence imaging visualized detail cellular structures. Regular glandular structures with polarized cell arrangement were observed in normal mucosa. Goblet cells were preserved in normal colonic mucosa. Irregular glandular structures with scanty cytoplasm and dispersed elongated nuclei were observed in adenomas. Goblet cells were scarce or lost in the colonic lesions. Similarity analysis between moxifloxacin and proflavine imaging showed relatively high correlation values in adenoma compared with those in normal mucosa. Dual fluorescence imaging showed good detection accuracies of 82.3% and 86.0% in the colonic and the gastric lesions, respectively.

CONCLUSIONS

High-contrast and high-resolution dual fluorescence imaging was feasible for obtaining detail histopathological information in the gastrointestinal neoplastic lesions. Further studies are needed to develop dual fluorescence imaging as an in vivo real-time visual diagnostic method.

Colorectal Sessile Serrated Lesion Detection Using Linked Color Imaging: A Multicenter, Parallel Randomized Controlled Trial

BACKGROUND & AIMS

Linked color imaging (LCI) is a novel technology that improves the color differences between colorectal lesions and the surrounding mucosa. The present study aims to compare the detection of colorectal sessile serrated lesions (SSL) using LCI with white light imaging (WLI).

METHOD

A large-scale, multicenter, parallel prospective randomized controlled trial was conducted in 4 hospitals in China. The participants were randomly assigned to the LCI group and WLI group. The primary endpoint was the SSL detection rate (SDR).

RESULTS

A total of 884 patients were involved in the intention-to-treat analysis, with 441 patients in the LCI group and 443 patients in the WLI group. The total polyp detection rate, adenoma detection rate, and SDR were 51.8%, 35.7%, and 8.6%, respectively. The SDR was significantly higher in the LCI group than in the WLI group (11.3% vs 5.9%, P = .004). Furthermore, LCI significantly increased the number of polyps and adenomas detected per patient, when compared with WLI (P < .05). In addition, there was higher detection rate of diminutive and flat lesions in the LCI group (P < .05). Multivariate analysis revealed that LCI is an independent factor associated with SDR (hazard ratio, 1.990; 95% confidence interval, 1.203-3.293; P = .007), along with withdrawal time (hazard ratio, 1.157; 95% confidence interval, 1.060-1.263; P = .001) and operator experience (hazard ratio, 1.850; 95% confidence interval, 1.045-3.273; P = .035).

CONCLUSIONS

LCI is significantly superior to WLI for SSL detection, and may improve polyp and adenoma detection. LCI can be recommended as an appropriate method for routine inspection during colonoscopy (http://www.chictr.org.cn number, ChiCTR2000035705).

Risk of colorectal advanced neoplasia in patients with acute diverticulitis with and without previous colonoscopy

BACKGROUND AND AIM

Guidelines recommend a colonoscopy after an episode of complicated diverticulitis and after a first episode of uncomplicated diverticulitis. The influence of a previous colonoscopy on postdiverticulitis colonoscopic findings has not been studied. The aim of this work was to examine the incidence of adenoma detection rate (ADR), advanced adenoma (AA) and colorectal cancer (CRC) in patients with diverticulitis with and without previous colonoscopy.

METHOD

This was a retrospective case-control study of subjects with acute diverticulitis. Subsequent and previous colonoscopies were abstracted for ADR, AA and CRC diagnoses. The incidence of neoplasia was compared between patients with and without previous colonoscopy and also with that of a screening population.

RESULTS

Compared with a healthy control group (n = 975), diverticulitis patients without prior colonoscopy (n = 325) had a significantly higher ADR (26.8% vs. 20.5%, p = 0.019) and invasive CRC rate (0.9% vs. 0%, p = 0.016). Risk factors for advanced neoplasia included age ≥ 70 years and complicated diverticulitis. Among subjects with diverticulitis and previous colonoscopy (n = 124), only one patient developed AA and there were no cancer cases.

CONCLUSIONS

A previous normal colonoscopy within 5 years before diverticulitis probably overshadows other risk factors for findings of advanced neoplasia and should be considered in the decision to repeat a colonoscopy.

Quality indicators in colonoscopy: observational study in a supplementary health system

PURPOSE

Colorectal cancer is responsible for 9.4% of cancer deaths, and low polyp detection rate and cecal intubation rate increase the risks of interval colorectal cancer. Despite several population studies that address colonoscopy quality measures, there is still a shortage of these studies in Latin America. The aim of this study was to assess quality indicators in colonoscopy, enabling future strategies to improve colorectal cancer prevention.

METHODS

An observational retrospective study, in which all colonoscopies performed in 11 hospitals were evaluated through a review of medical records. Information such as procedure indication, colorectal polyp detection rate, cecal intubation rate, quality of colonic preparation, and immediate adverse events were collected and analyzed.

RESULTS

In 17,448 colonoscopies performed by 86 endoscopists, 57.9% were in patients aged 50 to 74 years old. Colon preparation was adequate in 94.4% procedures, with rates of cecal intubation and polyp detection of 94 and 36.6%, respectively. Acute adverse events occurred in 0.2%. In 53.9%, high-definition imaging equipment was used. The procedure location, colon preparation and high-definition equipment influenced polyp detection rates (p < 0.001).

CONCLUSIONS

The extraction and analysis of electronic medical records showed that there are opportunities for improvement in colonoscopy quality indicators in the participating hospitals.

Mucosal imaging in colon polyps: New advances and what the future may hold

An expanding range of advanced mucosal imaging technologies have been developed with the goal of improving the detection and characterization of lesions in the gastrointestinal tract. Many technologies have targeted colorectal neoplasia given the potential for intervention prior to the development of invasive cancer in the setting of widespread surveillance programs. Improvement in adenoma detection reduces miss rates and prevents interval cancer development. Advanced imaging technologies aim to enhance detection without significantly increasing procedural time. Accurate polyp characterisation guides resection techniques for larger polyps, as well as providing the platform for the “resect and discard” and “do not resect” strategies for small and diminutive polyps. This review aims to collate and summarise the evidence regarding these technologies to guide colonoscopic practice in both interventional and non-interventional endoscopists.

Detection of colorectal adenomas with texture and color enhancement imaging: Multicenter observational study

OBJECTIVES

We aimed to evaluate the efficacy of texture and color enhancement imaging (TXI), which allows the acquisition of brighter images with enhanced color and surface structure in colorectal polyp detection compared to white light imaging.

METHODS

Patients who underwent colonoscopy with repeated ascending colon observation using TXI and white light imaging between August 2020 and January 2021 were identified in three institutions. The outcomes included the mean number of adenomas detected per procedure (MAP), adenoma detection rate (ADR), and ascending colonic adenoma miss rate (Ac-AMR). Logistic regression was used to determine the effects of the variables on the outcomes.

RESULTS

We included 1043 lesions from 470 patients in the analysis. The MAP, ADR, flat polyp detection rate, and Ac-AMR in TXI and white light imaging were 1.5% (95% confidence interval 1.3-1.6%) vs. 1.0% (0.9-1.1%), 58.2% (51.7-64.6%) vs. 46.8% (40.2-53.4%), 66.2% (59.8-72.2%) vs. 49.8% (43.2-56.4%), and 17.9% (12.1-25.2%) vs. 28.2% (20.0-37.6%), respectively. TXI, age, withdrawal time, and endoscopy type were identified as significant factors affecting the MAP and the ADR using multivariate regression analysis.

CONCLUSIONS

Our study indicates that TXI improve the detection of colorectal neoplastic lesions. However, prospective randomized trials are required to confirm these findings.

Linked color imaging improves visibility of colorectal serrated lesion by high color contrast to surrounding mucosa

OBJECTIVES

This study aimed to objectively evaluate the efficacy of linked color imaging (LCI) in diagnosing colorectal serrated lesions by utilizing visibility scores and color differences.

METHODS

We examined 89 serrated lesions, including 36 hyperplastic polyps (HPs), 47 sessile serrated lesions (SSLs), and six traditional serrated adenomas (TSAs). Visibility changes were scored by six endoscopists as follows: 4, excellent; 3, good; 2, fair; and 1, poor. Furthermore, images obtained by white-light imaging (WLI) or LCI were assessed using the CIELAB color space in the lesion and adjacent mucosa. We calculated the mean color values (L*, a*, and b*) measured at five regions of interest of the sample lesion and surrounding mucosa and derived the color difference (ΔE*).

RESULTS

The visibility scores of both HPs and SSLs in LCI were significantly higher than that in WLI (HPs, 3.67/2.89, P < 0.001; SSLs, 3.07/2.36, P < 0.001). Furthermore, SSLs showed a significantly higher L* value and significantly lower a* and b* values in LCI than the adjacent mucosae (L*, 61.76/58.23, P = 0.016; a*, 14.91/17.58, P = 0.019; b*, 20.42/24.21, P = 0.007), while WLI produced no significant difference in any color value. A similar trend was apparent in HPs. In all serrated groups, LCI revealed significantly greater ΔE* values between the lesion and adjacent mucosa than WLI (HPs, 11.54/6.12; SSLs, 13.43/7.67; TSAs, 35.00/22.48).

CONCLUSION

Linked color imaging showed higher color contrast between serrated lesions and the surrounding mucosae compared with WLI, indicating improved visibility of colorectal serrated lesion using LCI.

Trial protocol for COLO-DETECT: A randomized controlled trial of lesion detection comparing colonoscopy assisted by the GI Genius™ artificial intelligence endoscopy module with standard colonoscopy

AIM

Colorectal cancer is the second commonest cause of cancer death worldwide. Colonoscopy plays a key role in the control of colorectal cancer and, in that regard, maximizing detection (and removal) of pre-cancerous adenomas at colonoscopy is imperative. GI Genius™ (Medtronic Ltd) is a computer-aided detection system that integrates with existing endoscopy systems and improves adenoma detection during colonoscopy. COLO-DETECT aims to assess the clinical and cost effectiveness of GI Genius™ in UK routine colonoscopy practice.

METHODS AND ANALYSIS

Participants will be recruited from patients attending for colonoscopy at National Health Service sites in England, for clinical symptoms, surveillance or within the national Bowel Cancer Screening Programme. Randomization will involve a 1:1 allocation ratio (GI Genius™-assisted colonoscopy:standard colonoscopy) and will be stratified by age category (<60 years, 60-<74 years, ≥74 years), sex, hospital site and indication for colonoscopy. Demographic data, procedural data, histology and post-procedure patient experience and quality of life will be recorded. COLO-DETECT is designed and powered to detect clinically meaningful differences in mean adenomas per procedure and adenoma detection rate between GI Genius™-assisted colonoscopy and standard colonoscopy groups. The study will close when 1828 participants have had a complete colonoscopy. An economic evaluation will be conducted from the perspective of the National Health Service. A patient and public representative is contributing to all stages of the trial. Registered at ClinicalTrials.gov (NCT04723758) and ISRCTN (10451355). WHAT WILL THIS TRIAL ADD TO THE LITERATURE?: COLO-DETECT will be the first multi-centre randomized controlled trial evaluating GI Genius™ in real world colonoscopy practice and will, uniquely, evaluate both clinical and cost effectiveness.

Sessile serrated lesions: Clinicopathological characteristics, endoscopic diagnosis, and management

The 2019 World Health Organization (WHO) Classification of Tumours of the Digestive System (5th edition) introduced the term "sessile serrated lesion" (SSL) to replace the term "sessile serrated adenoma/polyp" (SSA/P). SSLs are early precursor lesions in the serrated neoplasia pathway that result in colorectal carcinomas with BRAF mutations, methylation for DNA repair genes, a CpG island methylator phenotype, and high levels of microsatellite instability. Some of these lesions can rapidly become dysplastic or invasive carcinomas that exhibit high lymphatic invasion and lymph node metastasis potential. The 2019 WHO classification noted that dysplasia arising in an SSL most likely is an advanced polyp, regardless of the morphologic grade of the dysplasia. Detecting SSLs with or without dysplasia is critical; however, detection of SSLs is challenging, and their identification by endoscopists and pathologists is inconsistent. Furthermore, indications for their endoscopic treatment have not been established. Moreover, SSLs are considered to contribute to the development of post-colonoscopy colorectal cancers. Herein, the clinicopathological and endoscopic characteristics of SSLs, including features determined using white light and image-enhanced endoscopy, therapeutic indications, therapeutic methods, and surveillance are reviewed based on the literature. This information may lead to more intensive research to improve detection, diagnosis, and rates of complete resection of these lesions and reduce post-colonoscopy colorectal cancer rates.

Association Between Endoscopist Specialty and Colonoscopy Quality: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

Colonoscopy quality indicators provide measurable assessments of performance, but significant provider-level variations exist. We performed a systematic review and meta-analysis to assess whether endoscopist specialty is associated with adenoma detection rate (ADR) - the primary outcome - or cecal intubation rate, adverse event rates, and post-colonoscopy colorectal cancer rates.

METHODS

We searched EMBASE, Google Scholar, MEDLINE, and the Cochrane Central Registry of Controlled Trials from inception to December 14, 2020. Two reviewers independently screened titles and abstracts. Citations underwent duplicate full-text review, with disagreements resolved by a third reviewer. Data were abstracted in duplicate. The DerSimonian and Laird random effects model was used to calculate pooled odds ratios (ORs) with respective 95% confidence intervals (CIs). Risk of bias was assessed using Risk of Bias in Non-randomised Studies of Interventions.

RESULTS

Of 11,314 citations, 36 studies representing 3,500,832 colonoscopies were included. Compared with colonoscopies performed by gastroenterologists, those by surgeons were associated with lower ADRs (OR, 0.81; 95% CI, 0.74-0.88) and lower cecal intubation rates (OR, 0.76; 95% CI, 0.63-0.92). Compared with colonoscopies performed by gastroenterologists, those by other (non-gastroenterologist, non-surgeon) endoscopists were associated with lower ADRs (OR, 0.91; 95% CI, 0.87-0.96), higher perforation rates (OR, 3.02; 95% CI, 1.65-5.51), and higher post-colonoscopy colorectal cancer rates (OR, 1.23; 95% CI, 1.14-1.33). Substantial to considerable heterogeneity existed for most analyses, and overall certainty in the evidence was low according to the Grading of Recommendations, Assessment, Development, and Evaluations framework.

CONCLUSION

Colonoscopies performed by surgeons or other endoscopists were associated with poorer quality metrics and outcomes compared with those performed by gastroenterologists. Targeted quality improvement efforts may be warranted.

Patient Selection, Risks, and Long-Term Outcomes Associated with Colorectal Polyp Resection

The 2 most significant complications of colonoscopy with polypectomy are bleeding and perforation. Although the incidence rates are generally low (<1%), these can be avoided by recognizing pertinent risk factors, which can be patient, polyp, and technique/device related. Endoscopists should be equipped to manage bleeding and perforation. Currently available devices and techniques to achieve hemostasis and manage colon perforations are reviewed.

Patient and Endoscopic Characteristics of Postcolonoscopy Colon Cancer-A Case-control Study

Background and Aims

Colonoscopy is imperfect for colorectal cancer (CRC) prevention. Postcolonoscopy CRC (PCCRC) is defined as CRC detected after a screening or surveillance colonoscopy. PCCRCs can be divided into noninterval CRC and interval CRC. We performed a case-control study to identify risk factors for PCCRCs and to compare risks between noninterval and interval PCCRCs.

Methods

We designed a retrospective case-control study. Using a Vermont tumor registry data set, we identified all PCCRCs diagnosed at our medical center from January 2012 to September 2017. Cases were matched 1:3 with controls of the same age, sex, and index colonoscopy date.

Results

Fifty-four PCCRCs were matched with 162 controls and divided into noninterval (N = 27) and interval (N = 27) subsets. Overall PCCRC risk and noninterval PCCRC risk were significantly associated with history of polyps (odds ratio [OR] PCCRC = 2.71, OR noninterval = 4.41), sessile serrated polyps (OR PCCRC = 3.94, OR noninterval = 5.79), and high-risk adenoma (HRA) (OR PCCRC = 6.58, OR noninterval = 16.46) and with the index colonoscopy having a large polyp (OR PCCRC = 4.45, OR noninterval = 10.46) or having an HRA (OR PCCRC = 3.68, OR noninterval = 8.04). PCCRC risk and interval PCCRC risk were significantly associated with follow-up recommendations that did not correlate with American Gastroenterological Association surveillance guidelines (OR PCCRC = 3.30, OR interval = 4.85). Approximately 30% of PCCRCs could be attributed to endoscopic quality.

Conclusion

Overall PCCRC risk and noninterval PCCRC risk were significantly associated with traditional CRC risk factors including precancerous polyps and HRA on the index colonoscopy. Interval PCCRC was not associated with these risk factors. Many PCCRCs can be attributed to endoscopic quality, and nonadherence to CRC surveillance guidelines may be a novel risk factor.

Risk of a post-colonoscopy colorectal cancer in patients with type 2 diabetes: a Danish population-based cohort study

Objective

Prevalent type 2 diabetes (T2D) is associated with an increased risk of colorectal cancer and could impair the quality of bowel preparation for colonoscopy. This may in turn increase the risk of overlooked precancerous polyps and subsequent risk of post-colonoscopy colorectal cancer (PCCRC). We investigated whether patients with T2D are at increased risk of PCCRC compared with patients without T2D.

Design

We conducted a population-based cohort study of patients with T2D and without T2D undergoing colonoscopy in Denmark (1995–2015). We investigated the risk of PCCRC by calculating >6 to 36 months cumulative incidence proportions (CIPs) treating death and colectomy as competing risks. Using Cox proportional-hazards regression analyses, we also computed HRs of PCCRC, comparing patients with T2D and non-T2D. According to the World Endoscopy Organization guidelines, we calculated PCCRC 3-year rates to estimate the proportions of T2D and non-T2D CRC patients experiencing PCCRC.

Results

We identified 29 031 patients with T2D and 333 232 patients without T2D undergoing colonoscopy. We observed 250 PCCRCs among patients with T2D and 1658 PCCRCs among patients without T2D. The >6 to 36 months CIP after a first-time colonoscopy was 0.64% (95% CI 0.55% to 0.74%) for T2D and 0.36% (95% CI 0.34% to 0.38%) for patients without T2D. The HRs of PCCRC were 1.43 (95% CI 1.21 to 1.72) after a first-time colonoscopy and 1.18 (95% CI 0.75 to 1.85) after a second-time colonoscopy. The PCCRC 3-year rate was 7.9% for patients with T2D and 7.4% for patients without T2D.

Conclusion

T2D may be associated with an increased HR of PCCRC.

The prevalence of sessile serrated lesion in the colorectum and its relationship to synchronous colorectal advanced neoplasia: a systemic review and meta-analysis

BACKGROUND

The aim of this systemic review and meta-analysis was to evaluate the prevalence of sessile serrated lesion (SSL) and its relationship to synchronous colorectal advanced neoplasia.

MATERIALS AND METHODS

Comprehensive, computerized research was performed on PubMed and published from 1 January 2010 to 6 July 2018 which searched relevant articles without any language limitations. Clinical trials were included in the narrative systemic review if they matched the following inclusion criteria: (1) published as a case-controlled study, cohort study or cross-sectional study; (2) defined objectively for diagnosis of SSL within the studies; (3) addressed the prevalence and characteristics of SSL. Within these trials, if they met additional criteria involving the reported outcome of risk regarding advanced neoplasia in relation to SSL, they were enrolled into meta-analysis.

RESULTS

Forty-one trials were enrolled for the systematic review, with a total of eight analyzed for the meta-analysis. The prevalence of all SSL ranged from 0.038 to 20.23% and the prevalence by pooled analysis was 2.7%. In a subgroup analysis, the overall prevalence of SSL during the periods of 2010-2014 and 2015-2018 was shown to be 2.7 and 2.8%, respectively. We calculated the pooled data on the cancer risk of SSL and the risk of synchronous advanced neoplasia in patients with SSL made available from the eight trials, which resulted in a pooled odds ratio of 3.53 (95% confidence interval 2.39-5.20, I2 = 4%, P = 0.40).

CONCLUSION

In this systemic review, SSL was found to be associated with an increased risk of synchronous advanced neoplasia in the colorectum.

A fecal-based test for the detection of advanced adenoma and colorectal cancer: a case-control and screening cohort study

BACKGROUND

Colorectal cancer (CRC) is the leading cause of cancer death worldwide. Screening is a confirmed way to reduce the incidence and mortality rates of CRC. This study aimed to identify a fecal-based, noninvasive, and accurate method for detection of colorectal cancer (CRC) and advanced adenoma (AA).

METHODS

Through detection in tissue (n = 96) and fecal samples (n = 88) and tested in an independent group of fecal samples (n = 294), the methylated DNA marker ITGA4 and bacterial markers Fusobacterium nucleatum (Fn) and Pepetostreptococcusanaerobius (Pa) were identified from the candidate biomarkers for CRC and AA detection. A prediction score (pd-score) was constructed using the selected markers and fecal immunochemical test (FIT) for distinguishing AA and CRC from healthy subjects by logistic regression method. The diagnostic performance of the pd-score was compared with FIT and validated in the external validation cohort (n = 117) and in a large CRC screening cohort.

RESULTS

The pd-score accurately identified AA and CRC from healthy subjects with an area under the curve (AUC) of 0.958, at a specificity of 91.37%; the pd-score showed sensitivities of 95.38% for CRC and 70.83% for AA, respectively. In the external validation cohort, the sensitivities of the pd-score for CRC and AA detection were 94.03% and 80.00%, respectively. When applied in screening, the pd-score identified 100% (11/11) of CRC and 70.83% (17/24) of AA in participants with both colonoscopy results and qualified fecal samples, showing an improvement by 41.19% compared to FIT.

CONCLUSIONS

The current study developed a noninvasive and well-validated approach for AA and CRC detection, which could be applied widely as a diagnostic and screening test.

Risk of a post-colonoscopy colorectal cancer diagnosis in patients with inflammatory bowel disease: a population-based cohort study

BACKGROUND : Post-colonoscopy colorectal cancers (PCCRCs) may account for up to 50 % of all colorectal cancers (CRCs) diagnosed in patients with inflammatory bowel disease (IBD). This may reflect a high colonoscopy frequency; however, evidence remains limited. METHODS : We conducted a cohort study of IBD and non-IBD patients undergoing colonoscopy. We calculated cumulative incidence proportions (CIPs) of PCCRC at 7-36 months after first-time and subsequent colonoscopies. We also computed crude and adjusted hazard ratios (HRs) of PCCRC, comparing IBD with non-IBD patients undergoing first-time and subsequent colonoscopies. Separate analyses were conducted for consecutive colonoscopies. We calculated 3-year rates of PCCRC to estimate the proportion of IBD and non-IBD CRC patients experiencing PCCRC. RESULTS : We observed 138 and 1909 PCCRCs among 34 688 IBD and 358 217 non-IBD patients who underwent colonoscopy. The CIP of PCCRC after first-time colonoscopy was 0.21 % (95 % confidence interval [CI] 0.17 %-0.27 %) for IBD patients and 0.37 % (95 %CI 0.35 %-0.39 %) for non-IBD patients. The adjusted HR of PCCRC after a first-time colonoscopy was 0.96 (95 %CI 0.75-1.22) and the adjusted HRs after subsequent colonoscopies had point estimates around 1.0. The 3-year PCCRC rate was 24.3 % (95 %CI 20.4 %-28.7 %) for IBD and 7.5 % (95 %CI 7.2 %-7.8 %) for non-IBD patients. CONCLUSIONS : Although PCCRCs accounted for a substantial proportion of all IBD-related CRCs, IBD patients had a low CIP of PCCRC. The elevated 3-year PCCRC rates may, among other factors, stem from the increased colonoscopy frequency in IBD patients.

Clinical and endoscopic characteristics of post-colonoscopy colorectal cancers detected within 10 years after a previous negative examination

Background and study aims We sometimes encounter colorectal cancer (CRC) that is discovered during the time interval between initial colonoscopy and the recommended follow-up examination. Although several studies reported such cases of CRC, most were based on registry data, which implied that the endoscopic quality was not consistent or guaranteed. We aimed to clarify these clinical and endoscopic characteristics at our high-volume center where a retrospective survey could be precisely performed.

Patients and methods We retrospectively analyzed patients with CRC who underwent endoscopic resection or surgery from April 2002 to December 2010, categorizing them into two groups: a “study group” of patients with a negative colonoscopy during the previous 10 years, and a “control group” of patients without a previous colonoscopy or with a previous colonoscopy more than 10 years prior.

Results A total of 2042 patients had CRC, among which 55 patients were classified into the study group and the remaining 1989 into the control group. The CRC cases in the study group showed a significant association with smaller (< 30 mm) tumor size (odds ratio [OR] 2.3; 95 % confidence interval [CI] 1.3–4.0) and proximal tumor site (OR 1.7; 95 %CI 0.9–2.9). In addition, right-sided and depressed-type T1 CRCs were significantly more common in the study group.

Conclusions Tumor size and location were associated with CRCs detected within 10 years after the negative examination. In addition, depressed-type T1 CRCs were more common. Therefore, we should pay more attention to small, right-sided, or depressed-type tumors in daily colonoscopy.

Cold snare polypectomy without submucosal injection: safety and efficacy in 615 large serrated lesions

Background and study aim  Cold resection is becoming the standard of care for the resection of nonpedunculated colon lesions up to 10 mm in diameter. Sessile serrated adenomas/polyps (SSA/Ps), including those ≥ 10 mm, present various characteristics that make them ideal candidates for cold snare polypectomy (CSP). Patients and methods  A prospectively maintained database was searched retrospectively for consecutive patients with lesions ≥ 10 mm resected between March 2013 and March 2018. During that period, all SSA/P-appearing lesions were resected using CSP without submucosal injection, except for lesions with endoscopic suspicion of dysplasia or submucosal invasion. Patients with a pathological diagnosis of SSA/P were included in the analysis. Adverse events were recorded up to 21 days following colonoscopy. Results  615 SSA/Ps ≥ 10 mm were resected during 452 colonoscopy procedures in 379 patients (mean age 54.1 years; standard deviation [SD] 11.9 years). Mean polyp size was 13.7 (SD 5.2) mm; 122 lesions (19.8 %) were ≥ 20 mm and 479 lesions (77.9 %) underwent piecemeal resection. Immediate adverse events included persistent abdominal pain that resolved spontaneously within 2 hours in three patients (0.8 %; 95 % confidence interval [CI] 0.2 %-2.3 %). One patient with persistent intraprocedural bleeding was successfully treated with a hemostatic clip. No late adverse events were detected. Surveillance colonoscopy was performed in 293 patients (77.3 %) at 23.4 (SD 11.6) months following index colonoscopy; residual/recurrent lesions were diagnosed in 23 patients (7.8 %; 95 %CI 5.0 %-11.6 %). Conclusion  CSP without submucosal injection appeared to be safe and effective for the resection of large SSA/Ps.

Cold versus hot polypectomy/endoscopic mucosal resection-A review of current evidence

Background

Colonoscopy with polypectomy substantially reduces the risk of colorectal cancer (CRC) but interval cancers still account for 9% of all CRCs, some of which are due to incomplete resection.

Aim

The aim of this review is to compare the outcomes of cold and hot endoscopic resection and provide technical tips and tricks for optimizing cold snare polypectomy.

Results

Cold snare polypectomy (CSP) is the standard technique for small (≤10 mm) colorectal polyps. For large colonic polyps (>10 mm), hot resection techniques with use of electrocautery (polypectomy or endoscopic mucosal resection) were recommended until recently. However, the use of electrocoagulation brings serious adverse effects in up to 9% of the patients, such as delayed bleeding, post‐polypectomy syndrome and perforation. In recent years, efforts have been made to improve the polypectomy with cold snare in order to avoid these adverse effects of electrocoagulation without compromising the efficacy of the resection. Several authors have recently shown that the complication rates of CSP of polyps >10 mm is close to zero and recurrence rates varies between 5‐18%. Lower recurrence rates are found in serrated lesions (<8%).

Clinical Features and Genomic Characterization of Post-Colonoscopy Colorectal Cancer

INTRODUCTION

Some colorectal cancers (CRCs) may be missed during colonoscopies. We aimed to determine the clinicopathological, biological, and genomic characteristics of post-colonoscopy CRCs (PCCRCs).

METHODS

Of the 1,619 consecutive patients with 1,765 CRCs detected between 2008 and 2016, 63 patients with 67 PCCRCs, when colonoscopies were performed 6-60 months before diagnosis, were recruited. After excluding patients with inflammatory bowel disease, familial polyposis syndrome, CRCs that developed from diminutive adenomatous polyps, and recurrent CRCs after endoscopic resection, 32 patients with 34 PCCRCs were enrolled. The lesions' clinicopathological features, mismatch repair proteins (MMRs), and genomic alterations were investigated.

RESULTS

The overall PCCRC-5y rate, rate of intramucosal (Tis) lesions, and rate of T1 or more deeply invasive cancers were 3.7% (66/1,764), 3.9% (32/820), and 3.6% (34/944), respectively. Thirty-three patients' MMRs were investigated; 7 (21%) exhibited deficient MMRs (dMMRs), comprising 4 with T2 or more deeply invasive cancers and 5 whose lesions were in the proximal colon. Twenty-three tumors' genomic mutations were investigated; PIK3CA had mutated in 5 of 6 T2 or more deeply invasive cancers, of which, 4 were located in the proximal colon. Two patients with dMMRs and BRAF mutations had poor prognoses. Sixty-one percent (17/28) of the macroscopic type 0 lesions were superficial. All superficial Tis and T1 PCCRCs were detected <24 months after the negative colonoscopies. They were distributed throughout the colon and rectum.

DISCUSSION

PCCRCs may be invasive cancers in the proximal colon that exhibit dMMRs and/or PIK3CA mutations or missed early CRCs especially superficial lesions.

[Post-colonoscopy Colorectal Cancer: Causes and Prevention of Interval Colorectal Cancer]

Colorectal cancer (CRC) is the third most commonly diagnosed cancer and the fourth leading cause of cancer death in the worldwide. Colonoscopy is the gold standard for screening and surveillance of CRC. Removing adenomas by colonoscopy has lowered the incidence and mortality of CRC. However, colonoscopy is imperfect for detection of colorectal neoplasia. After a colonoscopy that is negative for malignancy, CRC can be diagnosed. These are termed as post-colonoscopy CRC (PCCRC). The proportion of PCCRC, among all CRC was reported to be 1.8% to 9.0%. It occurred 2.4 times more in the right colon than in the left colon. The causes of PCCRC are missed lesions, incomplete resection, and new lesions. Among these causes, missed lesion and incomplete resection are procedural factors and preventable. Therefore, it is necessary to improve the quality of colonoscopy to minimize the occurrence of PCCRC.

Colorectal Cancer Epidemiology: Recent Trends and Impact on Outcomes

Colorectal cancer (CRC) is the third most common cancer and the second leading cause of cancer related deaths in the world with an estimated number of 1.8 million new cases and about 881,000 deaths worldwide in 2018. The epidemiology of CRC varies significantly between different regions in the world as well as between different age, gender and racial groups. Multiple factors are involved in this variation, including risk factor exposure, demographic variations in addition to genetic susceptibility and genetic mutations and their effect on the prognosis and treatment response. In this mini-review, we discuss the recent epidemiological trend including the incidence and mortality of colorectal cancer worldwide and the factors affecting these trends.

Prevalence and characteristics of post-colonoscopy colorectal cancers in a New Zealand regional centre: a 10-year analysis

BACKGROUND

Post-colonoscopy colorectal cancers (PCCRC) are cancers that appear following a colonoscopy in which no cancer is diagnosed. The occurrence of PCCRC is thought to be multifactorial, reflecting both endoscopy quality and potential differences in tumour biology between detected colorectal cancers and PCCRC.

AIM

To identify the prevalence and characteristics of PCCRC in a New Zealand regional centre over a 10-year period.

METHOD

All cases of colorectal cancer (n = 1055) in the Bay of Plenty region between 1 February 2009 and 1 February 2019 were cross-referenced with endoscopy coding records to identify patients who had undergone colonoscopy within the preceding 6-60 months in which cancer was not identified.

RESULTS

A total of 46 patients were identified to have PCCRC, giving a prevalence of 4.4%. The majority of these patients were older (80% aged 65 years or over) and female (67%). The mean interval between index colonoscopy and diagnosis of PCCRC was 3.03 years. Most (80%) patients had existent pathology (diverticular disease or colonic polyps) at index colonoscopy, and a significant proportion (43%) developed cancer in the same colonic segment. PCCRC were evenly distributed between the left (50%) and right (50%) colon. The majority of patients (63%) had early-stage cancer.

CONCLUSIONS

The prevalence of PCCRC in a New Zealand cohort is consistent with other international reports. Most patients with PCCRC are older, female and have early-stage disease. Of interest, a high proportion of patients developed cancer within a colonic segment with existent pathology, suggesting either missed lesions or incomplete polyp resection.

Impact of second forward-view examination on adenoma detection rate during unsedated colonoscopy: a randomized controlled trial

Objectives

Colorectal cancer on the right side of the colon has been suggested to be harder to detect by colonoscopy. The aim of this study was to evaluate whether a second forward-view examination of the right side of the colon could increase the adenoma detection rate (ADR) and/or polyp detection rate (PDR).

Methods

This was a single-centre randomized controlled trial. Patients undergoing colonoscopy were recruited and randomly assigned to the second forward-view examination (SFE) group, in which the right side of the colon was examined twice or the traditional colonoscopy (TC) group in which the colonoscopy was performed in a standard manner. The primary outcome was the ADR of right colon. The overall PDR and ADR, PDR of the right colon, per-adenoma miss rate of the right colon, and advanced lesion detection rate were also recorded and compared.

Results

A total of 392 patients were included in the study (SFE group 197 vs. TC group 195). The ADR and PDR of the right colon in the SFE group were significantly higher than those in the TC group (ADR 10.7% vs. 5.1%; P = 0.042); PDR 17.8% vs. 9.7%, P = 0.021). No significant difference was found in overall PDR/ADR, or advanced lesion detection rate between the two groups.

Conclusions

This prospective controlled study revealed that a second forward-view examination could modestly increase the ADR and PDR of the right colon during unsedated colonoscopies. This simple, safe and time-effective technique might be recommended for routine unsedated colonoscopy.

Trial registration: Clinical Trials.gov, NCT03619122. Registered on 7/8/2018.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-021-01783-9.

A Low Total Psoas Muscle Area Index Is a Strong Prognostic Factor in Metastatic Pancreatic Cancer

OBJECTIVES

The total psoas area index (TPI) is an emerging alternative to the total skeletal muscle area index as a prognostic factor but has never been evaluated in metastatic pancreatic cancer (mPC).

METHODS

Areas were manually recorded, as previously described. Sex-specific cutoffs were identified by optimum stratification of TPI using log-rank χ2 statistic associated with mortality to define sarcopenic psoas. Progression-free survival (PFS) and overall survival (OS) were the primary objectives. Two period groups were used as internal validation.

RESULTS

During the period study, 79 patients were treated for mPC. The TPI was correlated with PFS (hazards ratio, 0.81; P = 0.02) and OS (hazards ratio, 0.7; P < 0.001). Optimum thresholds defining sarcopenic psoas were less than 5.73 cm2/m2 in men and less than 4.37 cm2/m2 in women. Patients with sarcopenic psoas (62.0%) had shorter median PFS (2.9 months) compared with the others (6.6 months, adjusted P log-rank = 0.01), independently to the intensity of chemotherapy, weight loss, and performance status greater than 1. Similarly, OS was independently shorter in patients with sarcopenic psoas (7.6 months) versus the others (22.2 months, adjusted P < 0.001). These results were confirmed in the 2 period groups.

CONCLUSIONS

A low TPI is a stronger independent prognostic factor in mPC.

Clinical and endoscopist factors associated with post-colonoscopy colorectal cancer in a population-based sample

AIM

Factors associated with verified post-colonoscopy colorectal cancers (PCCRC) have not been well defined and survival for these patients is not well described. We aimed to assess the association of patient, tumour and endoscopist characteristics with PCCRC.

METHODS

Using population-based data, we identified individuals diagnosed with CRC from 1 January 2000 to 31 December 2005 who underwent a colonoscopy within 3 years prior to diagnosis. Detected cancers were those diagnosed ≤6 months following colonoscopy; PCCRC were diagnosed >6 months to ≤3 years following colonoscopy. Post-colonoscopy and detected cancers were verified through chart review using a hospital-based simple random sampling frame. We used multivariable conditional logistic regression to determine the association of patient, tumour and endoscopist factors with PCCRC and compared overall survival using Cox proportional hazard models.

RESULTS

Using the random sampling frame, we identified 498 patients with PCCRC and 498 with detected CRC; we obtained records and confirmed 367 patients with PCCRC and 412 with detected cancers. In multivariable analysis, patient age (OR 1.01; 95% CI 1.00-1.03) and tumour location (distal vs. proximal OR 0.36; 95% CI 0.25-0.53) were associated with PCCRC; endoscopist quality measures were not significantly associated with PCCRC. We did not find significant differences in overall survival between PCCRC and detected cancers (hazard ratio 1.12; 95% CI 0.92-1.32).

CONCLUSION

Although endoscopic quality measures are important for CRC prevention, endoscopist factors were not associated with PCCRC. This study highlights the need for further research into the role of tumour biology in PCCRC development.

ACG Clinical Guidelines: Colorectal Cancer Screening 2021

Colorectal cancer (CRC) is the third most common cancer in men and women in the United States. CRC screening efforts are directed toward removal of adenomas and sessile serrated lesions and detection of early-stage CRC. The purpose of this article is to update the 2009 American College of Gastroenterology CRC screening guidelines. The guideline is framed around several key questions. We conducted a comprehensive literature search to include studies through October 2020. The inclusion criteria were studies of any design with men and women age 40 years and older. Detailed recommendations for CRC screening in average-risk individuals and those with a family history of CRC are discussed. We also provide recommendations on the role of aspirin for chemoprevention, quality indicators for colonoscopy, approaches to organized CRC screening and improving adherence to CRC screening. CRC screening must be optimized to allow effective and sustained reduction of CRC incidence and mortality. This can be accomplished by achieving high rates of adherence, quality monitoring and improvement, following evidence-based guidelines, and removing barriers through the spectrum of care from noninvasive screening tests to screening and diagnostic colonoscopy. The development of cost-effective, highly accurate, noninvasive modalities associated with improved overall adherence to the screening process is also a desirable goal.

Panoramic colonoscopy in colorectal cancer screening - a randomized controlled trial

Introduction

Colonoscopy is considered the gold standard for colorectal cancer screening. Panoramic colonoscopy offers better visualization to decrease the adenoma miss rate.

Aim

To assess the influence of 330° panoramic view colonoscopy on adenoma and polyp detection rate, cecal intubation time, and examiner’s comfort.

Material and methods

The study enrolled 421 patients aged 18–80 years who were eligible for colonoscopy screening. Patients with prior abdominal surgery, inflammatory bowel disease or after colorectal resections were excluded from the study. Patients were randomized to either standard frontal view (SFV) (Olympus Evis Exera III 190 CF-HQ190L) or the panoramic view colonoscopy (PVC) (FUSE CDVL slim c38). The study was approved by the local bioethics committee and registered at ClinicalTrial.gov (NCT02929381).

Results

There were 214 patients examined with SFV and 207 with PVC. The mean age of patients was 64 ±12.26 years. The two groups were comparable. The median cecal intubation time was 234 s with SFV vs. 311 s with PVC (p < 0.001). There were no significant differences in CIR or withdrawal time. PVC made it possible to discover more diverticula in the ascending colon (p = 0.009). PDR with SFV was 34.6% and 40.1% with PVC (p = 0.242). A higher number of polyps was found in the transverse colon in the PVC group (p = 0.006). ADR and advanced ADR (aADR) in both groups were similar (26.4% vs. 27.1% and 14, 2% vs. 13.9%).

Conclusions

Colonoscopy with wide-angle endoscopes lasts longer and allows for the detection of more polyps and diverticula without affecting ADR and aADR. Our study did not reveal the superiority of wide-angle colonoscopy in colorectal cancer screening

Randomised comparison of postpolypectomy surveillance intervals following a two-round baseline colonoscopy: the Japan Polyp Study Workgroup

OBJECTIVE

To assess whether follow-up colonoscopy after polypectomy at 3 years only, or at 1 and 3 years would effectively detect advanced neoplasia (AN), including nonpolypoid colorectal neoplasms (NP-CRNs).

DESIGN

A prospective multicentre randomised controlled trial was conducted in 11 Japanese institutions. The enrolled participants underwent a two-round baseline colonoscopy (interval: 1 year) to remove all neoplastic lesions. Subsequently, they were randomly assigned to undergo follow-up colonoscopy at 1 and 3 years (2-examination group) or at 3 years only (1-examination group). The incidence of AN, defined as lesions with low-grade dysplasia ≥10 mm, high-grade dysplasia or invasive cancer, at follow-up colonoscopy was evaluated.

RESULTS

A total of 3926 patients were enrolled in this study. The mean age was 57.3 (range: 40-69) years, and 2440 (62%) were male. Of these, 2166 patients were assigned to two groups (2-examination: 1087, 1-examination: 1079). Overall, we detected 29 AN in 28 patients at follow-up colonoscopy in both groups. On per-protocol analysis (701 in 2-examination vs 763 in 1-examination group), the incidence of AN was similar between the two groups (1.7% vs 2.1%, p=0.599). The results of the non-inferiority test were significant (p=0.017 in per-protocol, p=0.001 in intention-to-treat analysis). NP-CRNs composed of dominantly of the detected AN (62%, 18/29), and most of them were classified into laterally spreading tumour non-granular type (83%, 15/18).

CONCLUSION

After a two-round baseline colonoscopy, follow-up colonoscopy at 3 years detected AN, including NP-CRNs, as effectively as follow-up colonoscopies performed after 1 and 3 years.

Clear colonoscopy as a surveillance tool in the prediction and reduction of advanced neoplasms: a randomized controlled trial

BACKGROUND

Missed and incompletely resected lesions remain the main cause of the recurrence of advanced neoplasms (ANs) in post-polypectomy patients. This study aims to determine whether the recurrence of ANs can be predicted and reduced by the newly developed clear colonoscopy procedure.

METHODS

Between 2006 and 2010, a total of 1350 participants with colorectal neoplasm were equally randomized to clear colonoscopy surveillance (CCS) and routine colonoscopy surveillance (RCS) in our center. Clear colonoscopy was achieved through repeat colonoscopy. On surveillance colonoscopy at 3 (for high-risk patients) and 5 (for low-risk patients) years, the recurrence of ANs and the relationship between the frequency of repeat examinations required for a clear colonoscopy and the recurrence of ANs were analyzed.

RESULTS

Surveillance colonoscopy at 3 and 5 years showed that the incidence of ANs in patients belonging to the CCS group was 1.7%, which was lower than 4.7% in patients belonging to the RCS group (P = 0.012) for both high- and low-risk patients. Out of the 1126 patients who achieved clear colonoscopy on first repeat examination, only 5 ( 0.4%) were found to have ANs on surveillance examination, whereas 12 out of the 217 (5.4%) patients on second repeat examination and 5 out of the 29 (17.2%) patients on third repeat examination were found to have ANs (P < 0.001).

CONCLUSION

Surveillance based on clear colonoscopy decreased the incidence of ANs in post-polypectomy patients. The number of repeat examinations required for a clear colonoscopy is an important factor in the prediction of the recurrence of ANs.

Usefulness of the Japan narrow-band imaging expert team classification system for the diagnosis of sessile serrated lesion with dysplasia/carcinoma

BACKGROUND

Sessile serrated lesion (SSL) is a colorectal polyp that has malignant potential. However, the dysplastic components within an SSL can be difficult to diagnose with conventional endoscopy, because most SSLs with dysplasia/carcinoma have subtle mucosal features. Many studies have indicated that narrow-band imaging (NBI) observations of colorectal polyps are very useful, accurate predictors of histology. We aimed to verify the usefulness of the Japan NBI Expert Team (JNET) classification system for the diagnosis of SSLs with dysplasia/carcinoma.

METHODS

We examined 709 endoscopically or surgically resected lesions that were pathologically diagnosed as SSL, including 647 with no dysplasia, 37 with low-grade dysplasia, 15 with high-grade dysplasia, and 10 with submucosal invasive carcinoma. We retrospectively evaluated their clinicopathologic characteristics and conventional endoscopic and magnifying NBI endoscopic findings using the JNET system.

RESULTS

Cases in all groups were more frequently located in the proximal colon. Submucosal invasive carcinomas were significantly larger than no dysplasia and low-grade dysplasia lesions. Almost all studied lesions (96.3%) were covered with a mucus cap. Five hundred and eighty (81.8%) lesions exhibited dark spots inside the crypts, which are NBI findings' characteristic of SSL. As for the JNET classification of magnifying NBI endoscopic findings, all 709 lesions showed Type 1. Six hundred and eighteen (95.5%) SSLs with no dysplasia lesions exhibited Type 1 only, whereas 52 (83.9%) SSLs with dysplasia/carcinoma had a combination of Type 1 and Type 2A, 2B, or 3, corresponding to SSL and dysplasia/carcinoma, respectively. The JNET classification had high sensitivity (83.9%), specificity (95.5%), and overall diagnostic accuracy (94.5%) for diagnosing SSLs with dysplasia/carcinoma.

CONCLUSIONS

Use of magnifying NBI endoscopy with the JNET classification might be useful for diagnosing SSLs with dysplasia/carcinoma. This increased awareness may also improve the recognition of SSLs with dysplasia/carcinoma.

Association between improved adenoma detection rates and interval colorectal cancer rates after a quality improvement program

BACKGROUND AND AIMS

Although colonoscopy reduces colorectal cancer (CRC) risk, interval CRCs (iCRCs) still occur. We aimed to determine iCRC incidence, assess the relationship between adenoma detection rates (ADRs) and iCRC rates, and evaluate iCRC rates over time concomitant with initiation of an institutional colonoscopy quality improvement (QI) program.

METHODS

We performed a retrospective cohort study of patients who underwent colonoscopy at an academic medical center (January 2003 to December 2015). We identified iCRCs through our data warehouse and reviewed charts to confirm appropriateness for study inclusion. iCRC was defined as a cancer diagnosed 6 to 60 months and early iCRC as a cancer diagnosed 6 to 36 months after index colonoscopy. We measured the relationship between provider ADRs and iCRC rates and assessed iCRC rates over time with initiation of a QI program that started in 2010.

RESULTS

A total of 193,939 colonoscopies were performed over the study period. We identified 186 patients with iCRC. The overall iCRC rate was .12% and the early iCRC rate .06%. Average-risk patients undergoing colonoscopy by endoscopists in the highest ADR quartile (34%-52%) had a 4-fold lower iCRC risk (relative risk, .23; 95% confidence interval, .11-.48) than those undergoing colonoscopy by endoscopists in the lowest quartile (12%-21%). After QI program initiation, overall iCRC rates improved from .15% to .08% (P < .001) and early iCRC rates improved from .07% to .04% (P = .004).

CONCLUSIONS

We confirmed that iCRC rate is inversely correlated with provider ADR. ADRs increased and iCRC rates decreased over time, concomitant with a QI program focused on split-dose bowel preparation, quality metric measurement, provider education, and feedback. iCRC rate measurement should be considered a feasible, outcomes-driven institutional metric of colonoscopy quality.

The incidence and risk factors of sessile serrated adenomas in left side colon cancer patients after curative surgery

Sessile serrated adenomas (SSAs) are precursors of colorectal cancer (CRC). However, there are limited data on detection rates of this premalignant lesion during colonoscopy surveillance in patients with a history of left side colonic resection for cancer. We aimed to identify the incidence and risk factors of SSAs in post-left side colectomy patients.We retrospectively reviewed the medical records of patients who had undergone left side colectomy for colon and rectal cancer between September 2009 and September 2016 and had at least 1 follow-up colonoscopy. Patient baseline characteristics, SSA diagnoses and characteristics, and colonoscopy information were collected.In total, 539 patients were enrolled. At the first follow-up (mean duration 11.5 months), 98 SSAs were identified (22.2%). At the second follow-up (mean duration 25.8 months), 51 SSAs were identified in 212 patients (24.0%). Multivariate analysis showed that alcohol intake (hazard ratio [HR] 1.524; 95% confidence interval [CI] .963-2.411, P = .041), excellent bowel preparation (HR 2.081; 95% CI 1.214-3.567, P = .049), and use of a transparent cap (HR 1.702; 95% CI 1.060-2.735, P = .013) were associated with higher SSA incidence in the first surveillance colonoscopy, while body mass index (BMI) ≥ 25.0 (HR 1.602; 95% CI 1.060-2.836) was associated with a significantly increased risk of SSAs in the second surveillance.Considering the endoscopic appearance of SSAs, adequate bowel preparation and use of transparent caps during postoperative surveillance colonoscopy can increase the diagnosis rate. Modification of alcohol intake and BMI may reduce the incidence of SSAs in left side colon cancer patients.