Prior Colonoscopy Research Articles

The Utility of Multitarget Stool DNA Testing for Colorectal Cancer Screening After a Normal Colonoscopy.

Multitarget stool DNA (MT-sDNA) tests (here, Cologuard®) are currently used in average-risk patients as a primary method of screening for colorectal cancer. However, MT-sDNA testing has also been used in patients who previously underwent colonoscopy who wish to avoid repeat colonoscopy. Here, in a large primary care practice setting, our aim was to evaluate the diagnostic performance of MT-sDNA testing in patients with a previously normal colonoscopy. This retrospective cohort study included 5827 patients from 35 different primary locations in South Carolina. Patients aged 45 and above with a previously documented normal, high-quality colonoscopy prior to the MT-sDNA test date were included. High-risk patients and those with a previous negative MT-sDNA result were excluded. Of 5827 ordered MT-sDNA tests, 248 patients had a prior normal colonoscopy. The average time from initial colonoscopy to MT-sDNA testing was 7.3years. Of the 63 patients who had a positive MT-sDNA test, 41 patients (65%) completed follow-up colonoscopy and 40 patients had complete colonoscopy data. Of these 40 patients, 12 patients (30%) had advanced adenomas and none had colorectal cancer. Compared to patients without a previous colonoscopy, patients with prior colonoscopies had fewer adenomas of all types (1.6 vs 2.4) and fewer advanced adenomas (1.4 vs 2.0). Patients with a previously negative colonoscopy and subsequent positive MT-sDNA test were found to have a high rate of advanced adenomas on follow-up colonoscopy (30%). Thus, in patients with a previously negative colonoscopy, MT-sDNA testing may be a reasonable alternative screening option.

Frequency of Errors in Colorectal Lesion Description and Management Prior to Referral to A Tertiary Center

Background and AimsAccurate reporting of polyp characteristics is crucial for effective resource allocation in endoscopic resection referrals. We present our experience with pre-referral management of challenging colorectal lesions. MethodsWe reviewed a prospectively collected database of consecutive referrals for endoscopic resection of challenging colorectal lesions. The database included details of prior colonoscopies. We assessed pre-referral management using established guidelines. ResultsAmong 1,826 referred lesions in 1826 patients, size estimates were missing for 421 (24%) lesions; 56 (3.2%) were found twice as large as previously estimated, while 65 (3.7%) were half the previous estimate. Morphological descriptions were absent for 376 (22%) polyps. Tattooing was performed for 822 (47%) lesions, with 247 (30%) placed correctly. Of the 1,103 (77%) polyps biopsied, only 11 (1.1%) were classified as high-risk by the referring endoscopist. ConclusionsErrors in pre-referral management of challenging colorectal lesions are frequent. Improved adherence to national guidelines could enhance practice.

Association Between Time to Colonoscopy After Abnormal Fecal Immunochemical Test and Risk of Adenoma, Advanced Colorectal Neoplasia and Colorectal Cancer Incidence

Objective: Colorectal cancer (CRC) is a significant health concern in Thailand, with high incidence and late-stage diagnosis rates. This study investigates the timing of colonoscopy following a positive fecal immunochemical test (FIT) and identifies risk factors for colorectal neoplasms. Material and Methods: A retrospective analysis included Thai patients aged 50-75 with a positive FIT who underwent colonoscopy. Exclusions were made for prior colonoscopy, colorectal surgery history, hereditary syndromes, inflammatory bowel disease, and incomplete pathology reports. Data from January 2018 to December 2021 were assessed for demographics, colonoscopy findings, and pathology outcomes. Results: The study encompassed 2,717 participants with balanced age and gender distributions. Preliminary risk factors associated with the development of adenoma and advanced colorectal neoplasia (ACRN) included age [odds ratio (OR): 1.03, 95% confidence interval (CI): 1.02-1.05, p-value<0.001], gender (OR for males: 1.60 for adenoma, 1.69 for ACRN, p-value<0.001), and smoking (OR: 1.92, p-value=0.001). The timing of colonoscopy within one-year post-FIT did not exhibit statistically significant associations with adenoma, ACRN, or CRC. Conclusion: This study provides valuable insights into CRC screening in Thailand. It suggests that timing within a year of colonoscopy might not be the sole determinant of improved outcomes post-FIT. Preliminary risk factors encompassed age, gender, and smoking. Future studies should focus on larger cohorts to investigate adverse outcomes, such as late-stage CRC and CRC-related mortality.

Intended and Actual Participation in the Colorectal Cancer Screening Program.

The public generally has a positive view of colorectal cancer screening, but there is still room for improvement in participation rates. The aim of this study was to identify factors that are associated with intended and actual participation. We conducted a prospective cohort study of a random sample of insurees of the AOK (a statutory health insurance carrier) in the German federal state of Lower Saxony. 50-year-old men and 55-year-old women who were eligible for their first screening colonoscopy received a written questionnaire in June 2020, three weeks after being invited to undergo colorectal cancer screening. For those who intended to do so, we used multivariable logistic regression analysis to determine any statistical associations between sociodemographic and medical characteristics and participation rates within 30 months. 82.7% of the respondents (239/298) intended to participate, and 43.3% (129/298) actually did so within 30 months. The participation rates among persons who had already decided to have a stool test or a colonoscopy were 50.7% (36/71) and 55.2% (58/105), respectively; the participation rate among undecided persons was 33.3% (19/57). The strongest association in the regression model was with an already made appointment (OR = 11.1, 95% confidence interval: [3.9; 31.8]). After exclusion of the existingappointment variable from the regression model, living in a smaller town (OR = 2.41 [1.08; 5.35]) and a stated preference for colonoscopy (OR = 2.52; [1.20; 5.27]) were positively associated with participation. Insurees with a parent affected by colorectal cancer participated less frequently, even after adjustment for prior colonoscopies (OR = 0.31 [0.12; 0.80]). The wide gap between intended and actual participation implies that there is potential for improvement in the prevention of colorectal cancer, and that certain groups of people could benefit from targeted support in making their intention to undergo screening a reality. Because of the methodological limitations of this initial investigation, its findings need to be confirmed by further studies.

Early follow-up colonoscopy after colorectal cancer resection detects significant pathology.

Colonoscopy is a key component of surveillance after colorectal cancer (CRC) resection. Surveillance intervals for colonoscopy vary across the world, with a limited evidence-base to support guidelines. To evaluate the timing and outcome of colonoscopies after CRC resection. Retrospective cohort study on prospectively collected data. Included adult patients under surveillance following CRC resection. Patients with organ transplant, inflammatory bowel disease or colon cancer syndromes were excluded. The outcomes of the first (up to) three follow-up colonoscopies were audited and classified for presence of advanced neoplasia (advanced adenoma or adenocarcinoma). 980 patients underwent at least one follow-up colonoscopy with a median time to first colonoscopy of 12.4 months. The findings included 2.7% CRC and 13.2% advanced adenoma. Older age, stage IV disease, and synchronous cancers at surgery were significantly associated with a finding of advanced neoplasia at first colonoscopy. 562 patients underwent a second colonoscopy (median of 35 months after the first surveillance colonoscopy) with findings of 1.8% CRC and 11.4% advanced adenoma. Advanced adenoma on prior colonoscopy was associated with finding advanced neoplasia at the second colonoscopy. 288 patients underwent a third colonoscopy (median of 37 months from the preceding colonoscopy), with similar outcomes of advanced neoplasia being associated with advanced adenoma at the previous colonoscopy. 43 (4.4%) patients developed CRC whilst on surveillance. Timely surveillance after CRC resection is important for detecting advanced neoplasia, and prolonged intervals between colonoscopies in the early years after surgery should be avoided.

Diverticulitis Is Associated with Increased Risk of Colon Cancer-A Nationwide Register-Based Cohort Study.

Background: An association between diverticulitis and colon cancer has been proposed. The evidence is conflicting, and the guidelines differ regarding recommended follow-up with colonoscopy after an episode of diverticulitis. To guide regimes for follow-up, this study aimed to investigate if patients with diverticulitis have an increased risk of colon cancer. Methods: This study is reported according to the RECORD statement. We performed a cohort study with linked data from nationwide Danish registers. The inclusion period was 1997-2009, and the complete study period was 1995-2013. The primary outcome was the risk of developing colon cancer estimated using a Cox regression analysis with time-varying covariates. We performed a sensitivity analysis on a cohort of people with prior colonoscopies, comparing the risk of colon cancer between the diverticulitis group and the control group. Results: We included 29,173 adult males and females with diverticulitis and 145,865 controls matched for sex and age. The incidence proportion of colon cancer was 2.1% (95% confidence interval (CI) 1.9-2.3) in the diverticulitis group and 1.5% (95% CI 1.4-1.5) in the matched control group (hazard ratio 1.6; 95% CI 1.5-1.8). The risk of having a colon cancer diagnosis was significantly increased in the first six months after inclusion (hazard ratio 1.7; 95% CI 1.5-1.8), and hereafter there was a lower risk in the diverticulitis group compared with controls (hazard ratio 0.8; 95% CI 0.7-0.9). This protective effect lasted eight years. The increased risk of colon cancer during the first six months after diverticulitis was also found in the cohort with prior colonoscopies. Conclusions: The risk of a colon cancer diagnosis was significantly increased for patients with diverticulitis 0-6 months after the diagnosis of diverticulitis. Hereafter, we found a protective effect of diverticulitis until eight years later, possibly due to a screening effect. We recommend a follow-up colonoscopy after the first diagnosis of diverticulitis.

Antibiotic prophylaxis prior to colonoscopy with biopsy does not decrease risk of prosthetic joint infection in total knee arthroplasty recipients

IntroductionProsthetic joint infection (PJI) risk continues to receive much attention given its associated morbidity and costs to patients and healthcare systems. It has been hypothesized that invasive colonoscopies may increase the risk of PJI. However, the decision to administer antibiotic prophylaxis lacks clinical guidance. In this study we aimed to compare PJI rates in patients undergoing colonoscopies with and without antibiotic prophylaxis against a control group, analyzing PJI occurrences at 90 days, 6 months, 9 months, and 1-year post-procedure and (2) assess the impact of antibiotic prophylaxis on PJI rates to inform clinical guidelines. MethodsWe queried a national, all-payer database to identify all primary total knee arthroplasty procedures without prior history of PJI between January 2010 and October 2020 (n = 1.9 million). All patients who had a diagnosis of PJI within one year of index procedure were excluded. There were three cohorts identified: colonoscopy with biopsy without antibiotic prophylaxis; colonoscopy with biopsy with antibiotic prophylaxis; and a control of no prior colonoscopy. Both colonoscopy cohorts were slightly younger and had higher comorbidities than the controls. The PJI diagnoses were identified at four separate time intervals within one-year after colonoscopy: 90-days; 6-months; 9-months; and 1-year. Chi-square analyses with odds ratios (ORs) and 95% confidence intervals were conducted for PJI rates between groups at all time-points. ResultsAmong all cohorts, no significant differences in PJI rates were found at 90-days (P = 0.459), 6-months (P = 0.608), 9-months (P = 0.598), and 1-year (P = 0.330). Similarly, direct comparison of both colonoscopy groups, with and without antibiotic prophylaxis, demonstrated no PJI rate differences at 90-day (P = 0.540), 6-months (P = 0.812), 9-months (P = 0.958), and 1-year (P = 0.207). Ranges of ORs between the colonoscopy cohorts were 1.07–1.43. ConclusionInvasive colonoscopy does not increase the risk of PJI in patients who have pre-existing knee implants. Furthermore, antibiotic prophylaxis may not be warranted in patients undergoing colonoscopy who have a planned biopsy.

Colorectal neoplasia surveillance in inflammatory bowel disease

Performing colorectal neoplasia surveillance in persons with inflammatory bowel disease (IBD) that is both clinically effective and cost effective is among the greatest challenges facing endoscopists who care for this population. While heightened colorectal cancer (CRC) risk has long been recognized among persons with IBD, this risk has been declining over time, with recent reports suggesting no more than a 1.5–2-fold higher risk compared to age and sex matched members of the general population. Nonetheless, given that CRC still occurs at a higher rate in this population, current surveillance strategies are inadequate for some persons. Conversely, 80–90% of persons with IBD had no neoplastic lesions identified during colonoscopy surveillance, suggesting that many persons with IBD are unnecessarily exposed to the risks of colonoscopy, with society bearing these excess costs.
 The purpose of colorectal neoplasia surveillance is to reduce the burden of CRC and CRC-related death in the IBD population. Societal guidelines recommend initiating colorectal neoplasia screening with colonoscopy in all persons with colorectal IBD involving at least the rectosigmoid (or at least 1/3 of the colorectum if accompanied by discontinuous inflammation) at 8–10 years following disease diagnosis and continuing lifelong surveillance every 1–5 years. Major factors influencing surveillance frequency include historical disease severity, extent of colorectal inflammation, chronic post-inflammatory changes, family history of CRC, history of colorectal neoplasm, primary sclerosing cholangitis, prior colonoscopy findings, and adequacy of prior surveillance. All guidelines further recommend targeted sampling or resection of suspicious visible abnormalities, and some societies continue to recommend extensive non-targeted biopsies to detect “invisible” neoplasia, particularly if other adjunctive optical modalities, such as dye-spray chromoendoscopy (DCE) or virtual chromoendoscopy (VCE), are not performed, or if the mucosa is poorly visualized, such as in areas of significant inflammation, post-inflammatory polyposis, or poor bowel preparation. Most societies now advocate for DCE or VCE as primary screening tools for IBD neoplasia surveillance or, at a minimum, as alternative modalities to traditional white light colonoscopy with non-targeted biopsies where resources and expertise exists.
 However, there are no prospective studies demonstrating a reduction in the incidence of CRC or of death from CRC with current surveillance strategies in persons with IBD. Furthermore, observations from large retrospective studies are also conflicting. A Cochrane analysis of 3 studies in persons with UC did not find a significant mortality benefit for current surveillance strategies. Considering that IBD afflicts many persons at a young age, is rising in prevalence in Canada and globally, and requires intensive lifelong surveillance , the amount of endoscopy resources directed toward IBD surveillance is potentially enormous. Increasing demands on colonoscopy resources from expansion of population-based CRC screening programs and an aging population are likely to challenge the ability to continue to provide intensive surveillance to all persons with IBD. Optimizing delivery of limited colonoscopy resources will thus be essential to maintain effective CRC prevention programs in this population.
 Current standards for neoplasia surveillance in IBD have been recently updated. Shah and Itzkowitz authored a comprehensive review that includes epidemiology, pathogenesis, and management of colorectal neoplasia, along with a chart that compares surveillance recommendations put forward by multiple societies. The present review will highlight new evidence influencing neoplasia surveillance and provide practical approaches for surveillance and management of neoplastic lesions in the IBD population.

The Role of Artificial Intelligence in Colorectal Cancer Screening: Lesion Detection and Lesion Characterization.

Colorectal cancer remains a leading cause of cancer-related morbidity and mortality worldwide, despite the widespread uptake of population surveillance strategies. This is in part due to the persistent development of 'interval colorectal cancers', where patients develop colorectal cancer despite appropriate surveillance intervals, implying pre-malignant polyps were not resected at a prior colonoscopy. Multiple techniques have been developed to improve the sensitivity and accuracy of lesion detection and characterisation in an effort to improve the efficacy of colorectal cancer screening, thereby reducing the incidence of interval colorectal cancers. This article presents a comprehensive review of the transformative role of artificial intelligence (AI), which has recently emerged as one such solution for improving the quality of screening and surveillance colonoscopy. Firstly, AI-driven algorithms demonstrate remarkable potential in addressing the challenge of overlooked polyps, particularly polyp subtypes infamous for escaping human detection because of their inconspicuous appearance. Secondly, AI empowers gastroenterologists without exhaustive training in advanced mucosal imaging to characterise polyps with accuracy similar to that of expert interventionalists, reducing the dependence on pathologic evaluation and guiding appropriate resection techniques or referrals for more complex resections. AI in colonoscopy holds the potential to advance the detection and characterisation of polyps, addressing current limitations and improving patient outcomes. The integration of AI technologies into routine colonoscopy represents a promising step towards more effective colorectal cancer screening and prevention.

S792 Utility of Repeating Colonoscopy for Evaluation of Lower Gastrointestinal Bleeding in Patients Who Have Had Prior Colonoscopy

S792 Utility of Repeating Colonoscopy for Evaluation of Lower Gastrointestinal Bleeding in Patients Who Have Had Prior Colonoscopy

Frequency of serrated polyposis syndrome recognition by community endoscopists.

Background and study aims Some data indicate serrated polyposis syndrome (SPS) is underdiagnosed. We determined the frequency of SPS diagnosis by community endoscopists prior to referral to a tertiary center. Patients and methods We performed a retrospective analysis of a prospectively collected database of SPS patients at a tertiary academic hospital. There were 212 patients who were referred to our center for resection of one or more lesions detected at a prior colonoscopy and who had records available that allowed determination of whether SPS was diagnosed before referral. Results Only 25 of 212 patients (11.8%) had a diagnosis or suspicion of a polyposis syndrome prior to referral, and only 12 patients (5.7%) had a specific SPS diagnosis made prior to referral. Among 187 patients diagnosed at our center, 39 had sufficient serrated lesions removed and documented in outside records to meet SPS criteria prior to referral, but the diagnosis was not made by the referring physician despite adequate numbers of lesions resected. The remaining cases required lesions removed at our center to meet SPS diagnostic criteria. Limitations were a single center, single expert endoscopist. Conclusions SPS is the most common colorectal polyposis syndrome, but it remains underdiagnosed by community endoscopists. Underdiagnosis may contribute to post-colonoscopy colorectal cancer in patients with SPS.

Impacts of COVID-19 on Appropriate Use of Screening Colonoscopy in a Large Integrated Healthcare Delivery System.

Decreasing low-value colonoscopy is critical to optimizing access for high-need patients, particularly in resource-constrained environments such as those created by the COVID-19 pandemic. We hypothesized that rates of screening colonoscopy overuse would decline during COVID compared to pre-COVID due to enhanced procedural scrutiny and prioritization in the setting of constrained access. To characterize impacts of COVID-19 on screening colonoscopy overuse DESIGN: Retrospective national cohort study using Veterans Health Administration administrative data PARTICIPANTS: Veterans undergoing screening colonoscopy in Q4 2019 (pre-COVID) and Q4 2020 (COVID) at 109 endoscopy facilities MAIN MEASURES: Rates of screening colonoscopy overuse KEY RESULTS: 18,376 screening colonoscopies were performed pre-COVID, 19% (3,641) of which met overuse criteria. While only 9,360 screening colonoscopies were performed in Q4 2020, 25% met overuse criteria. Overall change in median facility-level overuse during COVID compared to pre-COVID was 6% (95%CI 5%-7%), with significant variability across facilities (IQR: 2%-11%). Of colonoscopies meeting overuse criteria, the top reason for overuse in both periods was screening colonoscopy performed <9 years after previous screening procedure (55% pre-COVID, 49% during COVID). The largest shifts in overuse category were in screening procedures performed <9 years after prior screening colonoscopy (-6% decline COVID vs. pre-COVID) and screening procedures performed in patients below average-risk screening age (i.e., age <40 (5% increase COVID compared to pre-COVID), age 40-44 (4% increase COVID vs. pre-COVID)). Within facility performance was stable over time; 83/109 facilities changed their performance by <=1 quartile during COVID compared to pre-COVID. Despite pandemic-related resource constraints and enhanced procedural scrutiny and prioritization in the setting of COVID-related backlogs, screening colonoscopy overuse rates remained roughly stable during COVID compared to pre-COVID, with continued variability across facilities. These data highlight the need for systematic and concerted efforts to address overuse, even in the face of strong external motivating factors.

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.

Mortality After Postcolonoscopy Colorectal Cancer in the Veterans Affairs Health Care System

Postcolonoscopy colorectal cancer (PCCRC) refers to colorectal cancer (CRC) diagnosed after a colonoscopy in which no cancer was found and is reflective of colonoscopy quality at the individual and system levels. Colonoscopy is widely performed in the Veterans Affairs (VA) health care system, but the prevalence of PCCRC and its associated mortality are unknown. To examine PCCRC prevalence and its all-cause mortality (ACM) and CRC-specific mortality (CSM) within the VA health care system. This retrospective cohort study used VA-Medicare administrative data to identify 29 877 veterans aged 50 to 85 years with newly diagnosed CRC between January 1, 2003, and December 31, 2013. Patients whose colonoscopy occurred less than 6 months before CRC diagnosis with no other colonoscopy within the previous 36 months were categorized as having detected CRC (DCRC). Those who had a colonoscopy that did not detect CRC between 6 and 36 months before CRC diagnosis were categorized as having postcolonoscopy CRC (PCCRC-3y). A third group included patients with CRC and no colonoscopy within the prior 36 months. The final analysis of the data was performed in September 2022. Prior receipt of colonoscopy. Cox proportional hazards regression (with censoring, last follow-up December 31, 2018) analyses were conducted to compare PCCRC-3y and DCRC for 5-year ACM and CSM after CRC diagnosis. Of 29 877 patients with CRC (median [IQR] age, 67 [60-75] years; 29 353 [98%] male; 5284 [18%] Black, 23 971 [80%] White, and 622 [2%] other), 1785 (6%) were classified as having PCCRC-3y and 21 811 (73%) as having DCRC. The 5-year ACM rates were 46% vs 42% for patients with PCCRC-3y vs patients with DCRC. The 5-year CSM rates were 26% vs 25% for patients with PCCRC-3y vs patients with DCRC. In multivariable Cox proportional hazards regression analysis, there was no significant difference in ACM and CSM between patients with PCCRC-3y (adjusted hazard ratio [aHR], 1.04; 95% CI, 0.98-1.11; P = .18) and patients with DCRC (aHR, 1.04; 95% CI, 0.95-1.13; P = .42). However, compared with patients with DCRC, patients with no prior colonoscopy had significantly higher ACM (aHR, 1.76; 95% CI, 1.70-1.82; P < .001) and CSM (aHR, 2.22; 95% CI, 2.12-2.32; P < .001). Compared with patients with DCRC, patients with PCCRC-3y had significantly lower odds of having undergone colonoscopy performed by a gastroenterologist (odds ratio, 0.48; 95% CI, 0.43-0.53; P < .001). This study found that PCCRC-3y constituted 6% of CRCs in the VA system, which is similar to other settings. Compared with patients with CRC detected by colonoscopy, those with PCCRC-3y have comparable ACM and CSM.

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

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. 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. 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. 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.

P126 Ask twice: The importance of repeated faecal calprotectin testing prior diagnostic colonoscopy in an adult inception cohort

Abstract Background Elevated Faecal Calprotectin (FCP) is established as a valuable tool in differentiating Inflammatory Bowel Disease (IBD) from Irritable bowel syndrome (IBS) and monitoring IBD activity. Initial implementation studies in the UK demonstrated benefit from repeat testing to exclude false positives. This is not currently mandated by IBD consensus guidelines. Growing waiting times are increasing pressure to include a single result in straight to test pathways. No one level for significant elevation is defined with levels between 100-250ug/g used. We present our experience of the real-world utility of FCP used in a primary care referral pathway. Methods From Jan 2021-Nov 2022, new referrals were streamed into a rapid access ‘Inception IBD’ clinic on the basis of symptoms and raised FCP. A repeat FCP (kit sent in advance) was brought to the first appointment, with same day processing using the Buhlmann fCAL Turbo Test. Results and accompanying diagnosis and outcome data was collected prospectively. There was no standardised testing interval but median time from referral to review was 34 days. Results A single FCP was available for 425 patients with a final diagnosis. Two pre-treatment FCPs were available in 185. Median initial FCP was 949ug/g in those subsequently diagnosed with IBD (Ulcerative colitis 1162ug/g, Crohn’s 893ug/g) vs 353ug/g in those without IBD. This difference heightened on retesting, with median FCP in IBD 749ug/g vs 34ug/g in non-IBD (Fig 1). FCP fell between 1st and 2nd measurement in 88.6% of patients who had IBD excluded. In IBD, baseline FCP showed strong correlation with established disease activity markers (Fig 2). Baseline FCP levels were significantly higher in IBD patients who went on to require biologic treatment (Mann-Whitney U 2763, p&amp;lt;0.001). A variety of FCP cut-off values were assessed (Fig 4). A two sample &amp;gt;200ug/g cut off performed best as assessed by Area Under the Curve (AUC). However, sensitivity fell to 81.5% at this level. Of 15 IBD patients who didn’t have two FCPs &amp;gt;200ug/g, 7 had an increase between the 1st and 2nd FCP (median 147 vs 487ug/g). The remaining 8 comprised 4 ileal Crohn’s, 3 mild proctitis and 1 stricturing colonic Crohn’s in whom FCP failed to correlate with disease activity. Overall, 83% (48/58) of patients with increasing 1st to 2nd FCP were diagnosed with IBD. Conclusion Our data supports repeat testing of FCP to avoid unnecessary investigations adding to post COVID endoscopy backlogs. A cut off of two values &amp;gt;200ug/g had the best overall performance but can miss a small number of IBD cases, particularly those with isolated ileal disease or a more indolent disease course. This cut off should not be used in those with a marked increase between 1st and 2nd result, where IBD is likely.

At What Age Should We Stop Colorectal Cancer Screening? When Is Enough, Enough?

There is strong evidence that colorectal cancer screening can reduce both colorectal cancer incidence and mortality. Guidelines recommend screening for individuals age 45 to 75 years, but are less certain about the benefits after age 75 years. Dalmat and colleagues provide evidence that individuals with a prior negative colonoscopy 10 years or more prior to reaching age 76 to 85 years, had a low risk of colorectal cancer, and would be less likely to benefit from further screening. It is important to note that this study population did not include individuals with a family history of colon cancer or a personal history of having high-risk adenomas. These data suggest that a negative colonoscopy can be an effective risk-stratification tool when discussing further screening with elderly patients. See related article by Dalmat et al., p. 37.

Multiple Negative Fecal Immunochemical Tests Reduce Risk of Advanced Neoplasia in a Colonoscopy Surveillance Program

In above-average-risk individuals undergoing colonoscopy-based surveillance for colorectal cancer (CRC), screening with fecal immunochemical tests (FIT) between colonoscopies might facilitate personalization of surveillance intervals. Because a negative FIT is associated with a reduced risk for CRC, we examined the relationship between number of rounds of negative FIT and risk for advanced neoplasia in individuals undergoing surveillance colonoscopy. We conducted a retrospective cohort study on 4021 surveillance intervals in 3369 individuals (50-74 years), who had completed a 2-sample FIT between colonoscopies, from 1 to 4 rounds at 1-2 yearly intervals, each with a negative result (<20 μg hemoglobin/g feces). Incidence of advanced neoplasia (CRC or advanced adenoma) was determined at the follow-up colonoscopy. Competing-risk regression was used to assess the association between multiple negative FIT results and the risk of advanced neoplasia within 2 years. The incidence of advanced neoplasia in the cohort was 9.9% and decreased with increasing numbers of rounds of negative FIT results: 11.1% after 1 negative FIT to 5.7% after 4 negative FIT. The risk of advanced neoplasia was significantly lower in participants with 3 (subdistribution hazard ratio, 0.50; 95% confidence interval, 0.24-0.97) and 4 (subdistribution hazard ratio, 0.33; 95% confidence interval, 0.15-0.73) rounds of negative FIT compared with only 1 negative FIT. There was a low risk of advanced neoplasia after multiple rounds of negative FIT in above-average-risk people undergoing surveillance with no neoplasia or nonadvanced adenoma at prior colonoscopy. This supports the use of interval FIT to personalize surveillance by lengthening colonoscopy intervals following multiple negative FIT results.

Potential Impact of Extending Surveillance Intervals for Patients With 1-2 Low-Risk Adenomas.

Potential Impact of Extending Surveillance Intervals for Patients With 1-2 Low-Risk Adenomas.

Adherence to Recommendations for Repeat Surveillance After Publication of New Postpolypectomy Guidelines.

The 2012 and 2020 US Multi-Society Task Force postpolypectomy guidelines have recommended progressively longer surveillance intervals for patients with low-risk adenomas (LRAs). These guidelines require data from past colonoscopies. We examined the impact of the 2012 guidelines for second surveillance on clinical practice, including the availability of prior colonoscopy data, with the aim of informing the implementation of the 2020 guidelines. We identified surveillance colonoscopies at Stanford Health Care and the Palo Alto Veterans Affairs Health Care System in 3 periods: preguideline (March-August 2012), postguideline (January-June 2013), and delayed postguideline (July-September 2017). We collected data on the most recent previous colonoscopy, findings at the study entry surveillance colonoscopy, and recommendations for subsequent surveillance. Among 977 patients, the most recent prior colonoscopy data were available in 78% of preguideline, 78% of postguideline, and 61% of delayed postguideline cases (P < .001). The fraction of surveillance colonoscopy reports that deferred recommendations awaiting pathology increased from 6% to 11% in preguideline and postguideline to 59% in delayed postguideline cases (P < .001). Overall adherence to guidelines for subsequent surveillance was similar in all 3 periods (54%-67%; P= .089). In the postguideline and delayed postguideline periods combined, a 10-year subsequent surveillance interval was recommended in 0 of 29 cases with LRA followed by normal surveillance colonoscopy. In patients undergoing surveillance, prior colonoscopy data were not always available and recommendations were often deferred awaiting pathology. Adherence to subsequent surveillance guidelines was suboptimal, especially for LRA followed by normal colonoscopy. Strategies addressing these gaps are needed to optimize implementation of the updated 2020 postpolypectomy guidelines.