Index Colonoscopy Research Articles

Risk of metachronous colorectal cancer associated with polypectomy during endoscopic diagnosis of colorectal cancer

Background and aimThere are conflicting reports regarding the risk of metachronous colorectal cancer (CRC) subsequent to colonoscopy with polypectomy or biopsy performed concurrently with diagnostic biopsies for CRC. We aimed to establish the 5-year risk of CRC in patients who had synchronous polypectomy or biopsies during the colonoscopy at which CRC was diagnosed.MethodsThis is a single-centre retrospective case–control study of adults who underwent surgical resection for CRC over a 2-year period (January 2016 to December 2017). Colonoscopy details of interest were the location of the CRC, polypectomy and non-CRC biopsy sites. In patients with CRC at index colonoscopy, we sought associations between the occurrence of metachronous CRC and the sites from which endoscopic specimens had been obtained.ResultsOur study population comprised 225 patients with a median (IQR) age of 71 (60–77) years. Polypectomy or biopsy at a non-CRC site had been performed during the index colonoscopy in 108 patients (48%), including 83 (37%) polypectomies outside the surgical resection field. There were 8 (3.6%) metachronous CRCs: 1 (0.4%) at the site of endoscopic mucosal resection for a 15-mm sessile serrated lesion, 3 (1.3%) anastomotic site CRCs and 4 (1.8%) at other sites within the colon. There was no significant difference in the prevalence of metachronous CRC in patients who underwent polypectomy/biopsy at the index colonoscopy compared with those who did not (1.9% vs. 5.1%, p = 0.283).ConclusionThere was no significant increased risk of metachronous CRC subsequent to synchronous polypectomy or biopsy during the colonoscopy at which CRC was diagnosed.

Histologic healing and clinical outcomes in ulcerative colitis.

Growing evidence suggests histologic healing (HH) improves clinical outcomes in ulcerative colitis (UC) patients beyond endoscopic healing (EH). We hypothesize that HH is associated with better clinical outcomes in Asian UC patients, for whom data is lacking. We performed a retrospective study of UC patients in clinical remission (CR) with a follow-up colonoscopy and minimum 1-year follow-up post-colonoscopy. Primary outcome was clinical relapse (CRL), defined as either a Simple Clinical Colitis Activity Index score of > 2, medication escalation, hospitalization or colectomy. Predictors of CRL and HH were assessed. One hundred patients were included with a median follow-up of 22 months. At index colonoscopy, 80 patients were in EH. On follow-up, 41 patients experienced CRL. Of 80 patients in EH, 34 (42.5%) had persistent histologic activity (Nancy Index ≥ 2) and 29 (36.3%) relapsed during the follow-up period. Amongst patients in CR and EH, those with HH had lower CRL rate (26.1% vs. 50.0%, P= 0.028) and longer CRL-free survival (mean 46.1 months vs. 31.5 months, P= 0.015) than those with persistent histologic activity. On bivariable analysis of 100 patients in CR, HH, and Mayo endoscopic score (MES) of 0 were significantly associated with lower risk of CRL. On multivariable analysis, only MES 0 remained predictive of lower CRL risk. Above and beyond CR and EH, achieving HH improves clinical outcomes in Asian UC patients. However, HH may not confer incremental benefit if MES 0 has been achieved. Further prospective studies evaluating the benefit of histologically guided therapeutic decisions are needed.

Risk of colorectal neoplasia after removal of conventional adenomas and serrated polyps: a comprehensive evaluation of risk factors and surveillance use

BackgroundSurveillance colonoscopy after polyp removal is recommended to prevent subsequent colorectal cancer (CRC). It is known that advanced adenomas have a substantially higher risk than non-advanced ones, but optimal intervals...

Histologic improvement predicts endoscopic remission in patients with ulcerative colitis

Limited research has been performed to determine if histologic improvement serves as a prognosticator for endoscopic remission, a key therapeutic target for ulcerative colitis (UC). The primary aim of the study was to evaluate if histological activity could predict endoscopic remission in UC patients with Mayo endoscopic subscores (MES) of 0 or 1. In addition, we compared the clinical outcomes between histologic improvement group and active group. This research encompassed 492 individuals with UC with MES of 0 or 1, who underwent histological assessment as per the established protocol of Samsung Medical Center between January 2018 and December 2020. Participants were categorized into two cohorts based on the degree of histological activity: those showing histologic improvement and those with ongoing histologic activity. The endoscopic activity was assessed during follow-up, and the primary outcome was endoscopic remission according to histologic activity. Out of the total participants, endoscopic activity was scrutinized in 435 patients during the colonoscopic follow-up and in 146 during the subsequent one. The histologic improvement group at the index colonoscopy was more likely achieve endoscopic remission than the histologic active group. Clinical relapse was more likely in the histologic active group than in the histologic improvement group.

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.

Histologic Activity From Neoterminal Ileal Biopsies in Patients With Crohn's Disease in Endoscopic Remission is Associated With Postoperative Recurrence.

Following ileocolic resection (ICR), the clinical importance and prognostic implications of histologic activity on biopsies in Crohn's disease (CD) patients with endoscopic remission are not well defined. The aim of this study was to determine if histologic activity in patients with endoscopic remission is associated with future risk of endoscopic and/or radiologic postoperative recurrence (POR). In this multicenter retrospective cohort study, adult patients with CD who underwent ICR between 2009 and 2020 with endoscopic biopsies of ileal mucosa from Rutgeerts i0 on index colonoscopy were included. The composite rate of endoscopic (Rutgeerts score ≥i2b) and radiologic (active inflammation on imaging) recurrence was compared in patients with and without histologic activity using a Kaplan-Meier survival analysis. A multivariable Cox proportional hazard regression model including clinically relevant risk factors of POR, postoperative biologic prophylaxis, and histology activity was designed. A total of 113 patients with i0 disease on index colonoscopy after ICR were included. Of these, 42% had histologic activity. Time to POR was significantly earlier in the histologically active versus normal group ( P = 0.04). After adjusting for clinical risk factors of POR, histologic activity (HR 2.37, 95% CI 1.17-4.79; P = 0.02) and active smoking (HR 2.54, 95% CI 1.02-6.33; P = 0.05) were independently associated with subsequent composite POR risk. In patients with postoperative CD, histologic activity despite complete endoscopic remission is associated with composite, endoscopic, and radiographic recurrence. Further understanding of the role of histologic activity in patients with Rutgeerts i0 disease may provide a novel target to reduce disease recurrence in this population.

Risk of advanced neoplasia after removal of colorectal adenomas with high-grade dysplasia

BackgroundMany studies reported the presence of adenomas with high-grade dysplasia (HGD) at index colonoscopy increased the incidence of advanced neoplasia (AN) and colorectal cancer (CRC) following. However, the conclusion remains obscure due to lack of studies on the specific population of adenomas with HGD. This study aimed to assess the long-term risk of AN and CRC after removal of adenomas with HGD.MethodsA total of 814 patients who underwent adenomas with HGD removal between 2010 and 2019 were retrospectively analyzed. The outcomes were the incidences of AN and CRC during surveillance colonoscopy. Cox proportional hazards models were utilized to identify risk factors associated with AN and CRC.ResultsDuring more than 2000 person-years of follow-up, we found that AN and CRC incidence densities were 44.3 and 4.4 per 1000 person-years, respectively. The 10-year cumulative incidence of AN and CRC were 39.1% and 5.5%, respectively. In the multivariate model, synchronous low-risk polyps (HR 1.80, 95% CI 1.10–2.93) and synchronous high-risk polyps (HR 3.99, 95% CI 2.37–6.72) were risk factors for AN, whereas participation in surveillance colonoscopy visits (HR 0.56, 95% CI 0.36–0.88 for 1 visit; HR 0.10, 95% CI 0.06–0.19 for ≥ 2 visits) were associated with decreased AN incidence. Additionally, elevated baseline carcinoembryonic antigen (CEA) level (HR 10.19, 95% CI 1.77–58.59) was a risk factor for CRC, while participation in ≥ 2 surveillance colonoscopy visits (HR 0.11, 95% CI 0.02–0.56) were associated with decreased CRC incidence. Interestingly, for 11 patients who developed CRC after removal of adenomas with HGD, immunohistochemistry revealed that 8 cases (73%) were deficient mismatch repair CRCs.ConclusionsPatients who have undergone adenoma with HGD removal are at higher risk of developing AN and CRC, while surveillance colonoscopy can reduce the risk. Patients with synchronous polyps, or with elevated baseline CEA level are considered high-risk populations and require more frequent surveillance.

Factors Predicting Loss of Remission in Crohn's Disease Patients in Endoscopic Remission in the Real World: Results From TARGET-IBD.

There is limited evidence that histologic remission improves outcomes in Crohn's disease (CD). We aimed to characterize a cohort of patients with CD in endoscopic remission and explore factors associated with subsequent loss of remission (LOR). In total, 4474 patients were enrolled in TARGET-IBD, a longitudinal, observational cohort study. Patients with a normal steroid-free colonoscopy (index) were defined as "in endoscopic remission" and were followed for LOR, defined as presence of inflammation, erosion, ulceration, or stricturing on a subsequent colonoscopy or commencement of steroids. Histologic activity was dichotomized using standard of care reports for active inflammation. Unadjusted and multivariable-adjusted Cox proportional hazards regression models were used to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs) of LOR in relation to independent variables. Of 658 patients with CD with steroid-free endoscopic remission, the majority were female (57%), white (83%), non-Hispanic (93%); 20% had ileal and 20% isolated colonic disease. Inflammatory (B1) disease was the most common phenotype (43%). Of these 658 patients, 257 (39%) had histologic inflammation on index colonoscopy. Histologic inflammation at index colonoscopy was associated with nearly twice the LOR risk (HR 1.96, 95% CI: 1.50-2.57) with median time to relapse of 1.20 years. Biologic use at index was associated with lower LOR risk (monotherapy, HR 0.61, 95% CI: 0.45-0.82; combination therapy, HR 0.43, 95% CI: 0.28-0.66). Active histologic inflammation despite endoscopic remission, and lack of biologic use were independently associated with risk of subsequent LOR, providing evidence that histologic remission may impart improved outcomes in patients with CD.

Derivation and validation of a nomogram incorporating modifiable lifestyle factors to predict development of colorectal adenomas after negative index colonoscopy

This retrospective cohort study aimed to identify baseline patient characteristics involving modifiable lifestyle factors that are associated with the development of colorectal adenomas, and establish and validate a nomogram for risk predictions among high-risk populations with negative index colonoscopy. A total of 83,076 participants who underwent an index colonoscopy at the Tianjin Union Medical Center between 2004 and 2019 were collected. According to meticulous inclusion and exclusion criteria, 249 subjects were enrolled and categorized into the primary and validation cohorts. Based on the primary cohort, we utilized the LASSO-Cox regression and the univariate/multivariate Cox proportional hazards (Cox-PH) regression parallelly to select variables, and incorporated selected variables into two nomogram models established using the multivariate Cox-PH regression. Comparison of the Akaike information criterion and the area under the receiver operating characteristic curve of the two models demonstrated that the nomogram model constituted by four covariates retained by the LASSO-Cox regression, including baseline age, body mass index, physical activity and family history of colorectal cancer (CRC) in first-degree relatives, performed better at predicting adenoma-free survival probabilities. Further validation including the concordance index, calibration plots, decision curve analysis and Kaplan–Meier survival curves also revealed good predictive accuracy, discriminating ability, clinical utility and risk stratification capacity of the nomogram model. Our nomogram will assist high-risk individuals with negative index colonoscopy to prevent colorectal adenoma occurrence and CRC morbidity with improved cost-effectiveness.

Infliximab Tissue Concentrations in Patients With Stable Ulcerative Colitis Are Correlated With More Durable Infliximab-associated Disease Remission.

We aimed to determine the correlation between tissue and plasma infliximab concentrations in an outpatient ulcerative colitis (UC) cohort based on histologic disease activity in addition to their relationship with long-term clinical outcomes. We assessed intraparticipant variability in infliximab concentrations between adjacent intestinal samples and the correlation between disease activity and tumor necrosis factor-α (TNF-α). A prospective cohort study was conducted in participants with UC receiving infliximab. Blood and 2 sigmoid colon biopsies were obtained at the index colonoscopy for infliximab and TNF-α quantification. Histological disease activity was assessed. Participants were followed for 2 years for the occurrence of hospitalization, surgery, disease relapse, and infliximab discontinuation. A positive correlation was observed between mean plasma and uninflamed tissue infliximab concentrations only (Rs = 0.75, P = .0071). Lower mean tissue infliximab concentrations correlated with a shorter time to disease relapse vs those with higher mean tissue concentrations (Rs = 0.77, P = .032). This was not seen when using plasma infliximab concentrations. Additionally, no significant intraparticipant variability of infliximab concentrations was observed for all participants independent of disease activity. Neither plasma nor tissue TNF-α correlated with disease activity. These findings support data generated in patients with Crohn's disease: plasma infliximab concentrations are reflective of infliximab exposure in tissue in the UC patient in remission, but not for those with active disease. Increasing tissue concentrations in the noninflamed tissues may improve durability of infliximab. Neither plasma nor tissue TNF-α appear to correlate with UC disease activity. Larger follow-up studies would be of benefit.

Periprosthetic Joint Infection in Patients With Arthroplasty Undergoing Perioperative Colonoscopy

Periprosthetic joint infection (PJI) is a rare but devastating complication. Most patients undergoing total joint arthroplasty (TJA) also need routine screening colonoscopy, in which transient bacteremia may be a potential source for hematogenous PJI. Patients and surgeons must decide on an optimal time span or sequence for these 2 generally elective procedures, but no such guidelines currently exist. To evaluate associations of colonoscopy with the risk of post-TJA PJI for the development of clinical practice recommendations for colonoscopy screening in patients undergoing TJA. This retrospective cohort study of Military Health System (MHS) beneficiaries older than 45 years who underwent TJA from January 1, 2010, to December 31, 2016, used propensity score matching and logistic regression to evaluate associations of colonoscopy with PJI risk. Statistical analyses were conducted between January and October 2023. Colonoscopy status was defined by Current Procedural Terminology code for diagnostic colonoscopy within 6 months before or 6 months after TJA. Periprosthetic joint infection status was defined by a PJI International Classification of Diseases code within 1 year after TJA and within 1 year from the post-TJA index colonoscopy date. Analyses included 243 671 patients (mean [SD] age, 70.4 [10.0] years; 144 083 [59.1%] female) who underwent TJA in the MHS from 2010 to 2016. In the preoperative colonoscopy cohort, 325 patients (2.8%) had PJI within 1 year postoperatively. In the postoperative colonoscopy cohort, 138 patients (1.8%) had PJI within 1 year from the index colonoscopy date. In separate analyses of colonoscopy status within 6 months before and 6 months after TJA, younger age, male sex, and several chronic health conditions (diabetes, kidney disease, and pulmonary disease) were each associated with higher PJI risk. However, no association was found with PJI risk for perioperative colonoscopy preoperatively (adjusted odds ratio, 1.10; 95% CI, 0.98-1.23) or postoperatively (adjusted odds ratio, 0.90; 95% CI, 0.74-1.08). In this large retrospective cohort of patients undergoing TJA, perioperative screening colonoscopy was not associated with PJI and should not be delayed for periprocedural risk. However, health conditions were independently associated with PJI and should be medically optimized.

Lead Time and Immortal Time Biases Impact the Calculation of Post-colonoscopy Colorectal Cancer Survival

The World Endoscopy Organization (WEO) standardized the reporting of post-colonoscopy colorectal cancers (PCCRCs), which account for 7% to 10% of colorectal cancers (CRCs).1 PCCRCs are diagnosed 6 to 36 months after a false negative colonoscopy. Detected CRCs (dCRCs) are diagnosed ≤6 months after an index true positive colonoscopy.2 PCCRC prognosis is unclear, with outcomes reported as comparable,3 superior,4 or inferior5,6 to those of dCRC. Because WEO terminology defines cases relative to the index colonoscopy, conventional survival analyses of PCCRC are susceptible to lead time and immortal time biases. We evaluated the influence of these biases on mortality in a population-based retrospective cohort of 10,938 dCRCs (93.8%) and 717 PCCRCs (6.2%). This study was set within Kaiser Permanente Northern California (KPNC), a large integrated health system, whose members are similar in demographic and socioeconomic characteristics to the Northern California region.7.

Prevalence and predictive factors of colorectal sessile serrated lesions in younger individuals.

Sessile serrated lesions (SSLs) are obscured lesions predominantly in the right-sided colon and associated with interval colorectal cancer; however, their prevalence and risk factors among younger individuals remain unclear. This retrospective study enrolled individuals who underwent index colonoscopy. The primary outcome was the SSL prevalence in the younger (<50 years) and older (≥50 years) age groups, while the secondary outcomes included clinically significant serrated polyps (CSSPs). Multivariable logistic regression was employed to identify predictors. Of the 9854 eligible individuals, 4712 (47.8%) were categorized into the younger age group. Individuals in the younger age group exhibited lower prevalences of adenomas (22.6% vs. 46.2%; P<0.001) and right-sided adenomas (11.2% vs. 27.2%; P<0.001) compared with their older counterparts. However, both groups exhibited a similar prevalence of SSLs (7.2% vs. 6.5%; P=0.16) and CSSPs (10.3% vs. 10.3%;P=0.96). Multivariable analysis revealed that age 40-49 years (odds ratio [OR] 1.81, 95%CI 1.01-3.23), longer withdrawal time (OR 1.17, 95%CI 1.14-1.20, per minute increment), and endoscopist performance (OR 3.35, 95%CI 2.44-4.58) were independent predictors of SSL detection in the younger age group. No significant correlation was observed between adenoma and SSL detection rates among endoscopists. SSLs are not uncommon among younger individuals. Moreover, diligent effort and expertise are of paramount importance in SSL detection. Future studies should explore the clinical significance of SSLs in individuals of younger age.

Abstract 4771: Assessment of Ki67 proliferation index in pre-malignant colonic adenomas: Implication for new biomarker testing to predict metachronous disease (The INCISE project)

Abstract Approximately 40% of patients are found to have polyps at bowel screening colonoscopy, which are associated with a higher risk of developing future polyps or colorectal cancer. The British Society of Gastroenterology 2020 (BSG20) guidelines stratify patients into high/low risk of metachronous disease, using the size, dysplasia, and number of polyps found at index colonoscopy. This study aims to explore the prognostic significance of Ki67 proliferation percentages in adenomatous polyps, with metachronous disease. Tissue microarray (TMA) was constructed from 1201 index adenomatous polyps with representative cores of basal and luminal adenomatous epithelia. 67% patients were identified as high risk at index colonoscopy. The median time to detect metachronous polyps was 55 months (range 6-72 months) with 56% of patients developing metachronous polyps by the end of follow-up. TMA was stained for Ki67 using immunohistochemistry. Ki67 proliferation percentages in adenomatous epithelia was quantified using QuPath. Data was split into training (n=830) and test (n=371) datasets. The Ki67 proliferation cutpoint was made using Survmine R package using the training dataset. X2 test was used to study associations with clinicopathological criteria and Kaplan survival analysis was used to assess Ki67 association with metachronous lesions. Ki67 percentages were higher in lumina than in basal adenomatous epithelium (median Ki67 were 63% &amp; 48%; respectively). Total Ki67 percentages were computed by averaging luminal and basal values. Thresholds of 70%, 64% and 59% were employed to classify patients into low/high categories based on luminal, basal or total percentages; respectively. In the training cohort, high luminal, basal or total Ki67 were associated with metachronous lesions (p values 0.032, &amp;lt;0.001 and 0.006; respectively). Other associations were significant between luminal or total Ki67 and location of index polyps (p=0.017 &amp; p=0.044; respectively), histology (p=0.019) and advanced future lesion status (p=0.002 &amp; p&amp;lt;0.001; respectively). In multivariate cox regression analysis, high Ki67 was an independent prognostic factor for metachronous polyps (luminal Ki67 HR=1.28, CI: 1.052-1.560, p=0.014; basal Ki67 HR=1.639, CI: 1.313-2.046, p&amp;lt;0.001; total Ki67 HR=1.344, CI: 1.105-1.635, p=0.003) when adjusted to number of index polyps and BSG20 risk score. BSG20 risk score stratification of patients in terms of metachronous disease was improved when combined with luminal, basal or total Ki67 in the training datasets (all p&amp;lt;0.05). Prediction of metachronous disease by the combined groups was validated in the test cohort for luminal, basal and total Ki67 (all p&amp;lt;0.05). High Ki67 proliferation rates in adenomatous polyps are independently associated with the development of metachronous polyps and may help improve the BSG20 criteria. Citation Format: Gerard P. Lynch, Aula Ammar, Christopher Bigley, Mark Johnstone, Jakub Jawny, Hannah Morgan, Jennifer Hay, Noori Maka, Stephen McSorley, Joanne Edwards. Assessment of Ki67 proliferation index in pre-malignant colonic adenomas: Implication for new biomarker testing to predict metachronous disease (The INCISE project) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4771.

Neoplasia detection in FIT positive screening colonoscopies compared with an age-controlled symptomatic cohort: a retrospective review

Colonoscopy following a positive FIT test in an average risk population is effective in reducing CRC incidence and mortality. While lower gastrointestinal symptoms remain a common cause for referral for colonoscopy, symptoms are poor predictors of clinically significant disease. The study was performed to compare neoplasia detection FIT +ve individuals and age-matched symptomatic cohorts. A single centre retrospective observational study was performed including all index colonoscopies performed on patients aged 60-70 from January 2015 to September 2021. Diagnostic yield was reported as adenoma detection rate, SSL detection rate, detection of high risk finding or adenocarcinoma. 8,106 colonoscopies were performed on patients aged 60-70 years. 3,695 (45.6%) originated from screening (FIT +ve). With exclusion criteria applied, 2,640 (59.9%) for screening and 1,767 (40.1%) for symptomatic patients were included. Median age in screening was 65 years (IQR 62-67) and 64 years in the symptomatic group (IQR 62-68), with male predominance in both groups (n=1,536, 58.1%, n=944, 53.4%). There were significant differences in both the ADR (56% vs 26.3%, p&amp;lt;0.01) and the SSLDR (10.4% vs. 8.1%, p=0.05) in the screening cohort compared to the symptomatic group. High risk findings (21.3% vs. 7.5%, p&amp;lt;0.01) were significantly more prevalent in the screening group with a considerably higher colorectal cancer (4.7% vs. 0.9%, p=&amp;lt;0.001) detection rate. FIT based triage significantly outperforms symptom based investigation for individuals in the 60-70 age group. Patients should be preferentially referred to organised colorectal cancer screening. FIT can be performed on symptomatic patients, to identify low risk individuals.

Post-polypectomy surveillance: follow-up recommendations from the Alberta Colorectal Cancer Screening Program.

In 2013, the Alberta Colorectal Cancer Screening Program (ACRCSP) initially published recommendations for post-colonoscopy follow-up and polypectomy. Over time, emerging evidence and evolving surveillance guidelines from various expert groups necessitated a comprehensive review to align with the healthcare landscape in Alberta. To accomplish this, an expert panel was convened. Using the Agree II tool, we identified high-quality Clinical Practice Guidelines that were relevant to the Alberta medical context. Recommendations from these guidelines were adapted to fit the specific needs of Alberta. Recognizing inconsistencies and gaps within the existing guidelines, we conducted targeted literature reviews to ensure a comprehensive and evidence-based approach to our recommendations. Our revised recommendations build upon the assumption that a high-quality index colonoscopy has been performed at baseline. They are intended to enhance the quality of care and reduce unnecessary procedures. As well, they align with the growing consensus in the scientific literature that individuals with low-risk tubular adenomas may not require aggressive colonoscopy surveillance. The updated Alberta recommendations aim to provide clear recommendations for practicing endoscopists, referring physicians, and their patients. They address crucial questions such as determining which patients should commence surveillance via colonoscopy and which individuals should return to average-risk screening using the fecal immunochemical test (FIT). Additionally, our recommendations outline the appropriate surveillance intervals for those requiring continued monitoring.

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 36months 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.

Implementation of Synoptic Reporting for Endoscopic Localization of Complex Colorectal Neoplasms.

Introduction Lack of documented tattooing of colorectal neoplasms at index colonoscopy results in high repeat preoperative colonoscopy rates. We developed national consensus recommendations for endoscopic localization and piloted an electronic synoptic reporting template. We report on the implementation and perceptions of using synoptic reporting to enhance colorectal lesion marking in a central Canadian healthcare system. Methods We implemented the template within our endoscopy reporting system and ran an infographic education campaign. We then conducted a follow-up email-based interview with all regional endoscopists. Thematic analysis and a mixed-methods triangulation approach were employed to synthesize qualitative and quantitative data. Results The interview was completed by 28/52 endoscopists (54%). Most (60.7%; n = 17) completed >100 colonoscopies and 71.4% (n = 20) identified six to 20 neoplasms requiring tattooingsince introduction. A total of 50% (n = 14) used the template. Those not using it were unaware of it (42.9%; n = 12), or preferred using narrative text (17.9%; n = 5). Users reported modest mean functionality scores (intuitiveness: 3.56/5; efficiency: 3.7/5) and high impact scores (credible: 4.22/5; informative: 4.21/5). However, the perception of the synoptic template's ability to reduce the repeat preoperative colonoscopy rate was more circumspect (3.76/5). Conclusions Endoscopists believed the synoptic template was a functional, impactful tool that would improve communication and help to decrease the repeat preoperative colonoscopy rate. However, synoptic template uptake was limited by provider awareness, therefore more educational efforts are needed to increase uptake.

A141 RISK OF TOTAL METACHRONOUS ADVANCED NEOPLASIA AFTER DETECTION OF PROXIMAL HYPERPLASTIC POLYPS, ADENOMAS, AND THEIR COMBINATION

Abstract Background Recent research findings have identified an association between proximal sessile serrated lesions (SSL) and a greater risk of advanced metachronous neoplasia, without significant impact of distal SSL. Aims The principal aim of this study was to assess the risk of total metachronous advanced neoplasia (T-MAN) at the follow-up (fu) colonoscopy after detection of proximal hyperplastic polyps (HP), adenomas and their combination at the initial colonoscopy. Methods Medical records for patients aged 45 to 74 who underwent colonoscopies in both 2014 and 2015 were reviewed. The primary outcome was the presence of T-MAN (comprising advanced adenomas or high-risk SL) during the follow-up colonoscopy depending on the presence of proximal HP, adenoma, or their combination at index colonoscopy. Secondary outcomes included assessing the risk of T-MAN at follow-up depending on index findings characteristics. Results 2014 patients were screened and 764 were included in the final analysis (44.1% male vs 55.9% female; mean age, 63y; median follow-up, 3.46 years). Patients with both proximal hyperplastic polyps and colonic adenomas during their initial colonoscopy had a significantly higher risk of developing T-MAN than patients with a combination of adenomas and distal HP or with only adenomas at index colonoscopy (30.5% vs 19%) [Hazard-ratio (HR)=1.95 (95% confidence interval (CI)1.3-2.9)]. A combination of proximal hyperplastic polyps and colonic adenomas is associated with a higher risk of T-MAN during follow-up than proximal HP alone (30.5% vs 13.9%) [HR=3.4 (95% CI 1.3-8.7)]. No statistically significant evidence was found to identify an increased risk of developing T-MAN at follow-up in patients presenting adenomas alone vs those with only proximal HP (19.1% vs 13.9%) [HR=1.9 (95% CI 0.75-4.7)]. Conclusions Patients with proximal hyperplastic polyps have an increased risk of presenting a T-MAN at the follow-up colonoscopy. Presenting a combination of hyperplastic polyps and adenomas indicates a higher risk of developing T-MAN than presenting an HP or adenoma alone. Funding Agencies Daniel von Renteln is supported by a "Fonds de Recherche du Québec Santé" career development award. He has also received research funding from ERBE Elektromedizin GmbH, Ventage, Pendopharm, Fujifilm and Pentax, and has received consultant or speaker fees from Boston Scientific Inc., ERBE Elektromedizin GmbH, and Pendopharm. Roupen Djinbachian is supported by a “Fonds de Recherche du Québec Santé/Ministère de la Santé et des Services Sociaux” clinical research award. The remaining authors declare that they have no conflict of interest.

Colorectal Neoplasia in Asian Americans Undergoing First Time Asymptomatic Average-risk Screening Colonoscopies.

We identified the prevalence and subtype of colorectal neoplasia removed during index screening colonoscopies in a large Asian American population. Asian Americans are the fastest growing demographic group in the United States yet there is a paucity of data on the characteristics of colorectal neoplasia found in this cohort. Cross-sectional study of 2208 index colonoscopies performed on average-risk Asian and White patients at a large, tertiary academic center. Patients were identified via diagnostic or procedure codes between 2015 and 2020, with retrospective classification of polyp histopathology. Univariate and multivariate analysis were performed to identify risk factors associated with colorectal neoplasia. A total of 2208 patients were identified, of which 1085 were Asian. When adjusted for age and sex, Asians were as likely as Whites to have any type of colorectal neoplasia [44.2% vs. 43.5%, odds ratio (OR)=0.93, (CI: 0.78-1.11)]. On multivariate analysis, Asians were less likely to have sessile serrated polyps (5.5% vs. 9.9%, OR=0.53, 95% CI: 0.38-0.73) and more likely to have tubular adenomas in the left colon (22.6% vs. 18.0%, OR=1.33, 95% CI: 1.08-1.64) compared with Whites. Quality measures, such as sessile serrated polyp detection rates, may need to take into account demographic factors such as race. The prevalence of colorectal neoplasia among Asian Americans is substantial and warrants efforts to promote optimal uptake of colorectal cancer screening tests.