Post-colonoscopy Colorectal Cancer Rates Research Articles

S451 Very Low Rate of Post-Colonoscopy Colorectal Cancer in Individuals at Average-Risk for Colorectal Cancer

S451 Very Low Rate of Post-Colonoscopy Colorectal Cancer in Individuals at Average-Risk for Colorectal Cancer

FP1.11 - An audit of post colonoscopy Colorectal cancers within a Northern Ireland Health and Social Care Trust

Abstract Background Post colonoscopy colorectal cancer (PCCRC) is defined as colorectal cancer found within 48 months of a colonoscopy in which no cancer was found. The British Society of Gastroenterology (BSG) proposes PCCRC rates as a key quality indicator of colonoscopy. Rates documented vary between 2-8%, with higher rates shown in Inflammatory Bowel disease (IBD). The English National Post Colonoscopy Colorectal Audit was established after recommendations from the World Endoscopy Organisation (WEO). We aim to establish the rates of PCCRC within this Health and Social Care Trust (HSCT). Method All CRCs diagnosed in our HSCT between January 2021 to December 2022 were retrospectively reviewed. Our definition for a PCCRC was one diagnosed between 0-48months after a colonoscopy. Information included whether the colonoscopy was complete, quality of bowel preparation, lesions detected, if resection of lesion was complete and if IBD was present. Results In this timeframe 524 CRCs were diagnosed in this HSCT, with 33(6.3%) having had a colonoscopy within the previous 48 months. Of the 33 PCCRCs, 21(63.6%) had a complete colonoscopy, 22(66.6%) had at least fair/satisfactory bowel preparation, 24(72.7%) had a lesion detected and 3(9%) had a prior diagnosis of IBD. Of those who had a lesion detected (n=24), 13(54%) had a complete resection and 10(41.6%) had a biopsy only or incomplete resection. Conclusions Our PCCRC detection rate is in keeping with previous published literature. Further analysis of the 33 cases should provide information on how we can reduce future PCCRCs.

Optimal bowel preparation for colonoscopy.

There is robust evidence to indicate a strong correlation between the bowel preparation status and adenoma detection rate (ADR), which directly impacts the incidence and mortality rate of postcolonoscopy colorectal cancer. Therefore, improving bowel preparation has been of increasing interest. In Japan, commercially available bowel preparation agents include polyethylene glycol, oral sodium sulfate, sodium picosulfate-magnesium citrate, magnesium citrate, and oral sodium phosphate; each has its own strengths and limitations. The timing of administration can also influence the efficacy of bowel preparation and patient tolerability. Furthermore, meta-analyses have suggested predictive factors for inadequate bowel preparation. A detailed understanding of these factors could contribute to reducing the need for repeat colonoscopy within 1 year, as recommended for patients with inadequate bowel preparation. Recent advancements, such as oral sulfate tablets, present promising alternatives with higher patient satisfaction and ADRs than traditional methods. Achieving optimal bowel preparation requires enhanced instructions, individualized regimens, and a comprehensive understanding of patient backgrounds and the characteristics of various bowel preparation agents. This article provides a concise overview of the current status and advancements in bowel preparation for enhancing the quality and safety of colonoscopy.

Preventable predictive factors of post-colonoscopy colorectal cancer in inflammatory bowel disease.

Post-colonoscopy colorectal cancer (PCCRC) is a colorectal cancer (CRC) diagnosed after a colonoscopy in which no cancer is detected (index colonoscopy). Although the overall cumulative rates of PCCRC are low in both the general population and inflammatory bowel disease (IBD) patients, the overall incidence of PCCRC in IBD is greater than that documented in the general population. This study aimed to identify the index colonoscopy-related factors and patients' characteristics influencing IBD-associated PCCRC development. We carried out an observational, retrospective study in which IBD-associated PCCRCs were diagnosed between 2010 and 2023. The PCCRC group was compared to a control cohort of IBD patients without CRC matched 1:1 by several demographic and clinical features as well as characteristics of index colonoscopy to minimize selection bias. Among 61 CRCs identified, 37 (61%) were PCCRC. Twelve of 37 (32%) PCCRC were diagnosed within 12 months after the previous negative colonoscopy, 15 (41%) within 12-36 months, and 10 (27%) within 36-60 months. In the multivariate analysis, the inadequate bowel preparation of the index colonoscopy (OR: 5.9; 95% CI: 11.1- 31.4) and the presence of high-risk factors for CRC (OR: 24.03; 95% CI: 3.1-187.8) were independently associated with PCCRC. Conversely, prior exposure to immunosuppressors/biologics (OR: 0.17; 95% CI: 0.03-0.83) and random biopsies sampling at index colonoscopy (OR:0.19; 95% CI: 0.04-0.85) were inversely associated with PCCRC. More than 50% of CRCs in our population were PCCRC. PCCRCs were associated with previous inadequate cleansing and occurred more frequently in high-risk patients.

Quantifying the cost savings and health impacts of improving colonoscopy quality: an economic evaluation

ObjectiveTo estimate and quantify the cost implications and health impacts of improving the performance of English endoscopy services to the optimum quality as defined by postcolonoscopy colorectal cancer (PCCRC) rates.DesignA...

Postcolonoscopy colorectal cancer: Prevalence, categorization and root-cause analysis based on the World Endoscopic Organization system

AimsThe World Endoscopy Organization (WEO) recommends that endoscopy units implement a process to identify postcolonoscopy colorectal cancer (PCCRC). The aims of this study were to assess the 3-year PCCRC rate and to perform root-cause analyses and categorization in accordance with the WEO recommendations. Patients and methodsCases of colorectal cancers (CRCs) in a tertiary care center were retrospectively included from January 2018 to December 2019. The 3-year and 4-year PCCRC rates were calculated. A root-cause analysis and categorization of PCCRCs (interval and type A, B, C noninterval PCCRCs) were performed. The level of agreement between two expert endoscopists was assessed. ResultsA total of 530 cases of CRC were included. A total of 33 were deemed PCCRCs (age 75.8±9.5 years; 51.5% women). The 3-year and 4-year PCCRC rates were 3.4% and 4.7%, respectively. The level of agreement between the two endoscopists was acceptable either for the root-cause analysis (k=0.958) or for the categorization (k=0.76).The most plausible explanations of the PCCRCs were 8 “likely new PCCRCs”, 1 (4%) “detected, not resected”, 3 (12%) “detected, incomplete resection”, 8 (32%) “missed lesion, inadequate examination”, and 13 (52%) “missed lesion, adequate examination”. Most PCCRCs were deemed noninterval Type C PCCRCs (N=17, 51.5%). ConclusionWEO recommendations for root-cause analysis and categorization are useful to detect areas for improvement. Most PCCRCs were avoidable and were likely due to missed lesions during an otherwise adequate examination.

Cancer Biology or Ineffective Surveillance? A Multicentre Retrospective Analysis of Colitis-Associated Post-Colonoscopy Colorectal Cancers.

Inflammatory bowel disease [IBD] is associated with high rates of post-colonoscopy colorectal cancer [PCCRC], but further in-depth qualitative analyses are required to determine whether they result from inadequate surveillance or aggressive IBD cancer evolution. All IBD patients who had a colorectal cancer [CRC] diagnosed between January 2015 and July 2019 and a recent [<4 years] surveillance colonoscopy at one of four English hospital trusts underwent root cause analyses as recommended by the World Endoscopy Organisation to identify plausible PCCRC causative factors. In total, 61% [n = 22/36] of the included IBD CRCs were PCCRCs. They developed in patients with high cancer risk factors [77.8%; n = 28/36] requiring annual surveillance, yet 57.1% [n = 20/35] had inappropriately delayed surveillance. Most PCCRCs developed in situations where [i] an endoscopically unresectable lesion was detected [40.9%; n = 9/22], [ii] there was a deviation from the planned management pathway [40.9%; n = 9/22], such as service-, clinician- or patient-related delays in acting on a detected lesion, or [iii] lesions were potentially missed as they were typically located within areas of active inflammation or post-inflammatory change [36.4%; n = 8/22]. IBD PCCRC prevention will require more proactive strategies to reduce endoscopic inflammatory burden, and to improve lesion optical characterization, adherence to recommended surveillance intervals, and patient acceptance of prophylactic colectomy. However, the significant proportion appearing to originate from non-adenomatous-looking mucosa which fail to yield neoplasia on biopsy yet display aggressive cancer evolution highlights the limitations of current surveillance. Emerging molecular biomarkers may play a role in enhancing cancer risk stratification in future clinical practice.

Post-colonoscopy rectal cancer in Swedish patients with Crohn's disease 2001-2015: a population-based case review study.

Post-colonoscopy colorectal cancer (PCCRC) is a key quality indicator of colonoscopy, and PCCRC rates are high in the IBD population. Rectal cancer, an important risk factor for PCCRC among patients with Crohn's disease (CD), has not previously been examined. Swedish adult patients with CD who underwent a colonoscopy within 36 months before a rectal cancer diagnosis between 2001 and 2015 were identified through the National Patient and Cancer registers. Their medical records were reviewed and a root-cause analysis and a sub-categorization according to the World Endoscopic Organization (WEO) were performed. Of 24 patients with CD and PCCRC in the rectum, 79% were men and the median age was 50 (IQR 45-59) years. The median disease duration was 21.5 (IQR 19-30) years. The cancer was located in the distal 5 cm of the rectum in 63% of the cases. Retroversion in the rectum was reported in only one case. The most common plausible explanation for PCCRC was 'possible missed lesion, prior examination adequate' (63%); when adding retroversion in the rectum, instead 77% of examinations were considered negative but deemed as inadequate. The most common PCCRC sub-category was non-interval type C (54%) and B (37%). Among those with type C, 38% should have been included in surveillance according to present guidelines. Better adherence to surveillance guidelines and more meticulous follow-up is warranted. The importance of performing rectal palpation and retroversion in the rectum is underscored and we suggest that this is included in the WEO algorithm.

Postcolonoscopy colorectal cancer: Prevalence, categorization and root-cause analysis based on the World Endoscopic Organization system

AimsThe World Endoscopy Organization (WEO) recommends that endoscopy units implement a process to identify postcolonoscopy colorectal cancer (PCCRC). The aims of this study were to assess the 3-year PCCRC rate and to perform root-cause analyses and categorization in accordance with the WEO recommendations. Patients and methodsCases of colorectal cancers (CRCs) in a tertiary care center were retrospectively included from January 2018 to December 2019. The 3-year and 4-year PCCRC rates were calculated. A root-cause analysis and categorization of PCCRCs (interval and type A, B, C noninterval PCCRCs) were performed. The level of agreement between two expert endoscopists was assessed. ResultsA total of 530 cases of CRC were included. A total of 33 were deemed PCCRCs (age 75.8±9.5 years; 51.5% women). The 3-year and 4-year PCCRC rates were 3.4% and 4.7%, respectively. The level of agreement between the two endoscopists was acceptable either for the root-cause analysis (k=0.958) or for the categorization (k=0.76).The most plausible explanations of the PCCRCs were 8 “likely new PCCRCs”, 1 (4%) “detected, not resected”, 3 (12%) “detected, incomplete resection”, 8 (32%) “missed lesion, inadequate examination”, and 13 (52%) “missed lesion, adequate examination”. Most PCCRCs were deemed noninterval Type C PCCRCs (N=17, 51.5%). ConclusionWEO recommendations for root-cause analysis and categorization are useful to detect areas for improvement. Most PCCRCs were avoidable and were likely due to missed lesions during an otherwise adequate examination.

Editorial: Optimizing the success of cold snare polypectomy in colonoscopy practice

Editorial: Optimizing the success of cold snare polypectomy in colonoscopy practice

Overall and Annual Postcolonoscopy Colorectal Cancer Rates in a Large Integrated Healthcare Setting: A Cross-Sectional Study

Overall and Annual Postcolonoscopy Colorectal Cancer Rates in a Large Integrated Healthcare Setting: A Cross-Sectional Study

P127 Inflammatory Bowel Disease-associated colorectal cancers: retrospective cohort study from a tertiary centre surveillance programme over 10 years

Abstract Background Patients with IBD have increased risk for developing colorectal cancer (CRC), with poorer survival, compared to those without IBD. Despite surveillance colonoscopy, IBD post-colonoscopy CRC (PCCRC) rates are unacceptably high at 28-45%. We define surveillance colonoscopy quality, IBD-dysplasia and IBD-CRC prevalence, IBD-CRC characteristics, and IBD PCCRC rates at a tertiary IBD centre. Methods The GI Reporting Tool (Unisoft Medical Systems) was searched for IBD surveillance colonoscopy reports from April 2008–December 2018. Electronic medical records were reviewed. IBD phenotype and diagnosis date was confirmed on the Lothian IBD Registry. Follow-up was until September 2022. Results 1892 colonoscopies from 1262 patients were included. Median follow-up was 7.1 (4.4, 9.5) years. 885/1262 (70.1%) had UC, 344/1262 (27.3%) had Crohn’s, and 33/1262 (2.6%) had IBD-U. Median disease duration at colonoscopy was 16.8 (11, 24.6) years. 1825/1892 (96.5%) colonoscopies achieved caecal intubation, 1735/1840 (94.3%) adhered to biopsy guidelines and 704/1892 (37%) used chromoendoscopy. Histological inflammation was identified in 873/1823 (47.9%) cases; 57.2% in the right colon. Bowel preparation was poor in 194/1892 (10.3%) procedures and the most documented reason for not performing chromoendoscopy. Poor bowel preparation was associated with 23/60 (38.3%) poorly tolerated and 29/52 (55.8%) incomplete colonoscopies. Moviprep was superior to Picolax (p&amp;lt;0.001). GI physicians were more likely to use chromoendoscopy (p&amp;lt;0.001), biopsy per guideline (p&amp;lt;0.001), and identify dysplasia (p=0.012) compared to surgical colleagues. Dysplasia was identified in 145/1892 (7.7%) colonoscopies: 84/1892 (4.4%) sporadic, 22/1892 (1.2%) IBD-associated, and 39/1892 (2.1%) unspecified. IBD-CRC is rare, at 0.8 cases per 1000 patient years. Within the study period, 20/1262 (1.6%) patients had CRC diagnosed. 17/20 (85%) had UC and 3/20 (15%) had Crohn’s. 15/17 (88%) UC patients had E3 disease. 11/20 (55%) presented with lymph node or distant metastasis. 8/20 (40%) tumours had mucinous differentiation; only 1/15 (6.7%) was well differentiated. IBD-CRC patients had longer disease duration (28.3 (19.7, 37.8) years) compared to patients without CRC (22.25 (16.42, 29.85) years) at follow-up (p=0.028). The 3-year PCCRC rate was 15%. Conclusion IBD-CRC is rare however IBD PCCRC rates are unacceptably high. While this may reflect disease biology, a new approach to IBD surveillance is urgently needed. Interventions could include dedicated IBD surveillance lists, patient education around bowel preparation, and pre-screening for inflammation (e.g. faecal calprotectin). Cancer registry database linkage is now essential for us to identify IBD-CRC cases not identified by surveillance.

Utilization and reproducibility of World Endoscopy Organization post-colonoscopy colorectal cancer algorithms: retrospective analysis.

Colorectal cancer (CRC) diagnosed following a cancer-negative colonoscopy is termed post-colonoscopy CRC (PCCRC). In addition to calculating PCCRC rates, the World Endoscopy Organization (WEO) recommends review of individual PCCRC cases, including categorization into interval/non-interval PCCRCs, and root cause analysis to determine the most plausible explanation. We aimed to test the usability, reproducibility, and outcomes of the WEO algorithms. All CRC cases diagnosed from January 2015 to December 2016 in a single organization were cross referenced with local endoscopy and pathology databases to identify cases of PCCRC. We assessed: 1) WEO most plausible explanation for PCCRC; and 2) WEO PCCRC interval/non-interval subtype categorization. Interobserver agreement was measured using Cohen's kappa (κ). Cases with interobserver variation underwent panel discussion to reach consensus. Among 527 patients with CRC, 48 PCCRCs were identified. A consistent most plausible explanation was found in 97 % of cases, showing almost perfect agreement (κ = 0.94). Most PCCRCs (66 %) were attributed to "possible missed lesion, prior examination adequate." Interval/non-interval categorization was consistent in 77 %, showing substantial agreement (κ = 0.67). Following panel discussion, consensus was reached in all cases. Overall, 15 % were categorized as interval and 85 % as non-interval PCCRCs (12 % type A, 31 % type B, and 42 % type C). Review of PCCRC cases using WEO recommendations was performed accurately at a local level using readily available clinical information. The high number of non-interval type B PCCRCs suggests a significant proportion of PCCRCs could be avoided by better adherence to recommended surveillance intervals.

Postcolonoscopy Colorectal Cancer in Sweden From 2003 to 2012: Survival, Tumor Characteristics, and Risk Factors

The rate of postcolonoscopy colorectal cancer (PCCRC) is a measure of colonoscopy quality, but there are conflicting results from studies of survival times of patients with PCCRC. We assessed survival times of patients with PCCRC and characterized the microscopic and macroscopic features of postcolonoscopy colorectal tumors. We performed a population-based cohort study using data from a database in Sweden, on 458,937 colonoscopies (54.0% women) performed from 2003 through 2012. Rates of colorectal cancer within 3 years of a colonoscopy were calculated based on the World Endoscopy Organization guidelines. Risk factors were evaluated using Poisson regression analysis. We used Cox regression models and Kaplan-Meier analyses, stratified by sex, to assess conditional survival. Logistic regression models were used to evaluate features of postcolonoscopy colorectal tumors, including stage location (right, left, or rectum) differentiation grade (high or low), synchronous tumors, perineural growth, resection margins, and mucinous and vessel characteristics. Within 36 months after a colonoscopy, there were 19,184 individuals who had received a diagnosis of CRC; 1384 of these were PCCRCs (7.2%). The proportion of individuals with PCCRC decreased from 9.4% in 2003 to 6.1% in 2012. The largest risk factors for PCCRC were a prior diagnosis of CRC (relative risk [RR], 3.31; 95% CI, 2.71-4.04), ulcerative colitis (RR, 5.44; 95% CI, 4.75-6.23), Crohn's disease (RR, 3.81; 95% CI, 2.98-4.87), and prior polypectomy (RR, 2.32; 95% CI, 1.97-2.72). Individuals with PCCRCs had shorter survival times than individuals with CRCs detected during the index colonoscopy. Multivariate hazard ratios for PCCRC were 2.75 for men (95% CI, 2.21-3.42) and 2.00 for women (95% CI, 1.59-2.52), respectively. Individuals with left-side PCCRC had shorter survival times than patients with CRC detected during the index colonoscopy. Postcolonoscopy colorectal tumors had increased odds of low differentiation grade (odds ratio, 1.27; 95% CI, 1.09-1.49) compared with colorectal tumors detected during the index colonoscopy. In an analysis of colonoscopies in Sweden, the rate of PCCRCs decreased from 9.4% in 2003 to 6.1% in 2012. Diseases that require surveillance (such as prior colorectal neoplasms and inflammatory bowel diseases) are the largest risk factors for PCCRC. Patients with PCCRC have shorter survival times than patients with CRC detected during their initial colonoscopy-especially women and patients with left-side tumors.

Sa2051 IMPACT OF LINKED COLOR IMAGING ON THE ADENOMA DETECTION RATE IN NAIVE GASTROENTEROLOGY TRAINEES: A RANDOMIZED CONTROLLED TRIAL

Adenoma detection rate (ADR) is the most widely used marker of quality, and low rates are associated with increased rates of post-colonoscopy colorectal cancer (CRC). As a newly developed image-enhanced endoscopy technique, linked-color imaging (LCI) provides very bright images with enhanced red-color tones and has been purported to increase ADR. Some studies suggest that LCI by experienced endoscopists may be more effective at detecting adenomas than white-light imaging (WLI). However, the usefulness of screening colonoscopy with LCI by novice trainees remains unknown. We undertook a randomized trial to evaluate the detection rates of colorectal polyps and adenomas with LCI in comparison to WLI during fellowship training. All colonoscopies for CRC screening were eligible for the study. Exclusion criteria included patient age <18 or >75 years, prior colon resection, or Boston bowel preparation scale (BBPS) less than 5. Patients were randomized to either LCI or WLI in a 1:1 fashion. The primary outcome was ADR. Secondary outcomes were polyp detection rate (PDR), adenoma per colonoscopy (APC), polyp per colonoscopy (PPC), and withdrawal time of each trainee throughout the first year of colonoscopy training. Further, these study outcomes were compared among the first 6-month and the last 6-month period of training. During November 2018 and October 2019, 6 trainees involved CRC screening in 804 patients with a mean age of 61.7±10.9 years, and 38% were male. Three hundred fifty-two patients and 452 patients underwent colonoscopic withdrawal using LCI and WLI, respectively. Patient characteristics were comparable between both groups concerning comorbidities, antiplatelet/anticoagulant usage, indication for the colonoscopy, and BBPS (Table1). Overall independent cecal intubation rate by trainees was 86.2%, and the performance of each trainee was similar between groups. However, the withdrawal time was shorter in the LCI group (14.6±8.3 min vs. 16.7±8.0 min, p<0.01). The mean ADR was 40.1% and 43.6% in LCI and WLI, respectively (p=0.32). The PDR, APC and PPC were not significantly different between both two groups. To evaluate learning curves for the quality of screening colonoscopy, the primary and secondary outcomes were compared among the first and second 6-month periods. The analysis showed that the ADR during both periods was not significantly different between the LCI and WLI groups (Table 2). The PDR, APC, and PPC between both groups were also similar between both periods. Overall, ADR by gastroenterology trainees reached the standard ADR recommended by international guidelines. Although withdrawal times with LCI were shorter than those of WLI, colonoscopy with LCI did not facilitate ADR and had no impact on the learning curve of CRC screening by novice trainees.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

BowelScope: Accuracy of Detection Using Endocuff Optimisation of Mucosal Abnormalities (the B-ADENOMA Study): a multicentre, randomised controlled flexible sigmoidoscopy trial

ObjectivesAdenoma detection rate (ADR) is an important quality marker at lower GI endoscopy. Higher ADRs are associated with lower postcolonoscopy colorectal cancer rates. The English flexible sigmoidoscopy (FS) screening programme...

Clinical implications of decision making in colorectal polypectomy: an international survey of Western endoscopists suggests priorities for change.

Introduction Colonoscopy prevents colorectal cancer via the detection and resection of premalignant polyps. This effect may be attenuated by variations in polypectomy, with multiple techniques available and a wide range of experience amongst endoscopists. We assessed current practice against the best available contemporary evidence. Methods An online survey was distributed to members of the gastroenterological and surgical societies of seven countries during July 2017. Images of colorectal polyps were presented and respondents requested to provide the polypectomy technique they would employ in their daily practice. Responses were compared to the evidence-based techniques in the 2017 ESGE Colorectal Polypectomy Guideline. Results In total, 707 endoscopists (627 physicians, 71 surgeons, 9 nurse endoscopists, median practice duration 18 years) completed the survey. Of these, 3.1 % selected hot biopsy forceps and 5.2 % hot snare polypectomy (without submucosal lifting) to remove a 3 mm ascending colon polyp. Only 43.3 % selected cold snare polypectomy (CSP) to remove an 8 mm ascending colon polyp. Surgical referral was selected by 16.7 % of respondents for a 45 mm transverse colon polyp without endoscopic evidence of submucosal invasive cancer (SMIC). Endoscopic resection was selected by 12.0 % for an 80 mm sigmoid polyp with imaging consistent with deep SMIC, and a further 26.4 % selected tertiary endoscopist referral, suggesting they had not appreciated that it was endoscopically unresectable. Conclusion CSP is underutilized for small polyp resection despite its favorable safety and efficacy. Benign polyps are commonly referred for surgery and overt SMIC is underappreciated using endoscopic imaging. Addressing these issues may reduce diathermy-related adverse events, surgery, and unnecessary colonoscopic procedures for patients and reduce rates of post-colonoscopy colorectal cancer.

Does Colon Polyp Surveillance Improve Patient Outcomes?

Colon polyp surveillance now accounts for 25% of all colonoscopies performed. The evidence that colonoscopy surveillance reduces colorectal cancer (CRC) incidence or mortality is weak. The biology of the baseline lesions and quality of the baseline exam are two primary factors contributing to post-colonoscopy CRC. Prior recommendations for surveillance were based largely on the likelihood that patients with adenomas would develop advanced adenomas, a surrogate for CRC. There is now evidence that baseline colonoscopy findings are strongly associated with the risk of incidence or death from CRC. This evidence provides a basis for updated evidence-based recommendations for surveillance. In addition, there is also growing evidence that the quality of the baseline exam is an important predictor of the likelihood of developing post-colonoscopy CRC.

234 Higher Serrated Detection Rate Is Associated With Lower Risk for Post-Colonoscopy Colorectal Cancer

INTRODUCTION: The serrated pathway may account for a significant proportion of colorectal cancer (CRC). Achieving adequate serrated polyp detection rates (SDR) may reduce the incidence of post colonoscopy CRC (PCCRC). We used data from the New Hampshire Colonoscopy Registry (NHCR) to determine if exams performed by endoscopists who have a clinically significant serrated polyp detection rate (CSSDR) of 7% or greater, proposed by Anderson/Butterly (GIE 2017), had a reduced incidence of PCCRC. In addition, we compared CSSDR to the adenoma detection rate (ADR), the currently used benchmark. METHODS: We defined PCCRC as any CRC diagnosed between 6 and 36 months after an exam with an adenoma on index and between 6 and 60 months following a normal exam. Exclusion criteria were any CRC diagnosed at index or within 3 months, incomplete exams, IBD, and genetic syndromes. Clinically significant serrated polyps (CSSP) were defined as any sessile serrated polyp, traditional serrated adenoma, serrated polyp &gt;1 cm anywhere in the colon and any serrated polyp &gt;5 mm proximal to the sigmoid. CSSDR was defined as number of screening exams with at least one CSSP divided by all screening exams. The exposure variable was a CSSDR of 7% and adenoma detection rate of 25%. Cox regression was used to model the risk of PCCRC in terms of the covariates at index exam. Covariates were age, BMI, smoking, index findings (large serrated polyp, advanced adenoma or any adenoma), followup time (months), bowel prep quality, having more than 1 surveillance exam and family history of CRC. We also compared receiver operating characteristics (ROC) for CSSDR 7% to an ADR 25% using probabilities derived from a logistic regression analysis. RESULTS: In our sample (142,950 index exams) 75 CRCs were diagnosed during the 6–60 month period (45 CRCs diagnosed between 6–36 months) after the index exam. The hazard ratio (HR) for CSSDR of 7% (HR = 0.37 95% CI 0.17–0.83) was similar to that for an ADR of 25% (HR = 0.45 95% 0.23–0.89) (Table 1). The ROCs were similar for CSSDR and ADR and the combination of the 2 rates did not alter the ROC (Table 2). CONCLUSION: Having an exam performed by an endoscopist with a CSSDR of 7% or greater was associated with a decrease incidence of PCCRC (HR = 0.37). The performance of CSSDR and ADR for PCCRC incidence were similar. These data suggest that a CSSDR of 7% or greater may be associated with lower PCCRC rates. However, it may not add an information to that provided by the current primary colonoscopy benchmark, ADR.

Colonoscopic miss rate for colorectal cancer: a district general hospital experience

Background: The aim of the study was to review our post-colonoscopy colorectal cancer (PCCRC) diagnoses rate and compare it to national standards, to identify any common factors in our missed cancer cases and create a policy for capturing missed cancers data.Methods: We analyzed retrospectively collected data on patients with colorectal cancer from January 2015 to July 2017. Patients who had a previous colonoscopy within 3 years of diagnosis were then identified. We excluded colonoscopies done within 6 weeks of diagnosis or repeat colonoscopies due to poor bowel preparation.Results: 503 colorectal cancer patients were identified. 135 (26.8%) were initially diagnosed without a lower GI endoscopy. 30 had a negative colonoscopy 6 weeks to 3 years prior to diagnosis. Only 10 patients (2.7%) were true missed lesions (false negative colonoscopy). Male/female: 5/5. Mean age was 68.4 (49-80). 9 patients had good or satisfactory bowel preparation. 50% of lesions were found during follow-up or treatment of a different lesion. Average time from false negative scope to diagnosis was 20.3 months (4-31). Sites of missed lesions are left colon- 4, low rectum- 3, caecum- 2 and transverse colon- 1.Conclusions: Our PCCRC rate is below the GUT recommended target of &lt;5% and well below the national average 8.5%. We identified no common features across all missed cases. Contrary to other published data, right sided lesions were less common with no female predominance. We recognize the limitations of access to only local trust data. We propose to monitor PCCRC rate annually, present this at clinical governance meetings and review each case individually as an adverse event.