Index Colonoscopy Research Articles

Normalization of C-Reactive Protein Predicts Better Outcome in Patients With Crohn's Disease With Mucosal Healing and Deep Remission.

OBJECTIVES:Therapeutic targets for Crohn's disease (CD) have evolved from clinical and biological remission to mucosal healing (MH) and deep remission (DR). MH is defined as disappearance of ulceration, whereas DR is defined as a combination of clinical remission and MH. Limited data are available regarding differences in long-term outcomes of these patients reaching these targets. We thus aimed to evaluate patients' long-term clinical outcomes using different composite remission parameters.METHODS:We performed a retrospective cohort study comparing long-term outcomes of patients with different remission parameters, including MH and DR with or without normalization of C-reactive protein (CRPnorm). The primary outcome was CD-associated intestinal surgery, and secondary outcomes included CD-related hospitalizations, clinical relapse (CR), or endoscopic recurrence (ER).RESULTS:One hundred ninety-five patients with MH at follow-up endoscopy were divided into 3 groups: DR-only (n = 53), DR + CRPnorm (n = 106), and MH-only (n = 36). At the follow-up (median 46.0 months), 25 patients had undergone CD-related bowel surgery, 44 had CD-related hospitalizations, and 66 experienced CR. Of 151 patients who underwent follow-up colonoscopy after the index colonoscopy for MH, 96 experienced ER. Among the 3 groups, patients in the DR + CRPnorm group had the lowest risk of clinical or endoscopic relapse. The DR group had a lower rate of CR than the MH-only group (P = 0.03); there was no difference in the rate of CD-related surgery, hospitalizations, or ER.DISCUSSION:Patients with DR combined with a normalized CRP showed better outcomes than those with DR only. The outcomes of patients with MH were similar to those of patients with DR, except for shorter flare-free survival.

Preventive effects of gender and metabolic syndrome in 40s on colorectal cancer by colonoscopy.

59 Background: This study was aimed at measuring the preventive effect of colonoscopy for CRC development depending on age of index colonoscopy, gender and metabolic syndrome among persons aged 40 to 59 years. Methods: Between January 2005 and December 2006, data for the population aged from 40 to 59 who underwent colonoscopy (CSP cohort) claimed were collected from National Health Insurance Service (NHIS). Non-CSP (N-CSP) subjects were also collected by 1:5 propensity score matching with parameters of age, sex, and metabolic profiles, smoking, alcohol and past history of cancer. After one year of washout period, the risk of developing CRC was estimated by the occurrence of new case from January 2009 to December 2014 using the link of National CRC Registry to NHIS database. Compared with N-CSP cohort, hazard ratios (HRs) were obtained via conditional logistic regression analysis to estimate the risk of CRC in CSP cohort by age groups. Results: A total of 2,339,359 subjects were included (CSP cohort: 395,738 and matched N-CSP cohort: 1,943,621). The HRs for developing CRC by ages of 40-44, 45-49, 50-54, and 55-59 years in a CSP cohort were 0.864 ( P = NS), 0.591 ( P < 0.001), 0.599 ( P < 0.001), and 0.524 ( P < 0.001) in men, and 0.774 ( P = NS), 0.841 ( P = NS), 0.598 ( P < 0.001), and 0.605 ( P < 0.001) in women, respectively. Interestingly, when confined to patients with metabolic syndrome in their 40s, HRs for CRC in the colonoscopy cohort were statistically significantly lowered to 0.372 in early 40’s and 0.386 in men of late 40s, respectively, but not in women of 40s. Conclusions: The CRC prevention effect of colonoscopy is expected from late 40s in men and early 50s in women. Furthermore, in cases with metabolic syndrome, the preventive effect of colonoscopy is expected in men of early forties.

P114 PERIANAL EXAMINATION AT TIME OF COLONOSCOPY - A MISSED OPPORTUNITY FOR IBD ASSESSMENT

Abstract Introduction The subtype of inflammatory bowel disease (IBD) is often not known at index colonoscopy and examining for perianal disease (PAD) can assist in establishing the diagnosis. PAD is common in Crohn’s disease (CD) but can also be seen in patients with ulcerative colitis (UC) in the form of fissures, abscesses and fistulae. Absence of perianal symptoms does not exclude PAD. Performing a routine perianal examination in a busy outpatient setting is not ideal and the endoscopy suite may be more appropriate. We hypothesise that perianal examinations are being omitted during IBD assessment colonoscopy. Methods Unisoft GI Reporting Tool was used to identify the last 70 consecutive CD and UC assessment colonoscopies performed over a 12 month period (August 2018 and July 2019) at a London-based district general hospital. Data was collected on demographics, known PAD, previous imaging and performance of perianal examination at colonoscopy. Results 140 patients undergoing colonoscopy for IBD assessment were included in this study (70 CD, 70 UC).Median age 42 (IQR 32 – 55), Female 66 (47.1%). 15 (10.7%) had known perianal disease. Pelvic MRI had previously been performed in 20(14.3%). Perianal examination was performed in only 3 (2%) patients at the time of their last clinic consultation. Although digital rectal examination (DRE) was performed in 132 (93.6%) of patients at the time of colonoscopy, only 9 (6.4%) had a perianal examination documented. Conclusion About 10% of patients in our cohort undergoing IBD assessment colonoscopy were known to have PAD but perianal examination was performed in only 2% of patients during clinic consultation and 6% during colonoscopy. Perianal examination at time of endoscopic assessment is an ideal setting to perform an intimate examination as you have an exposed, sedated and chaperoned patient. The omission of perianal examination at colonoscopy is a missed opportunity and improvement in this key element of disease assessment is required.

P397 Surveillance in ulcerative colitis: Can we predict the risk for intraepithelial neoplasia?

Abstract Background Ulcerative colitis (UC) has been associated with an increased risk of colorectal cancer (CRC). Although dye spray chromoendoscopy showed superiority to standard colonoscopy in surveillance studies, with the availability of higher-resolution colonoscopes, the utility of chromoendoscopy (CE) has been questioned. We aimed to evaluate the risk of intraepithelial neoplasia (IN) after a high-quality screening colonoscopy (making use of CE or random biopsies (RB) and removing all detected lesions) in a population with longstanding UC and to identify potential risk factors for dysplasia incidence. Methods In a previous study, 145 patients with clinically and endoscopic longstanding (≥8 yr) distal/extensive UC without primary sclerosing cholangitis and/or history of IN were prospectively randomised to undergo CE or RB. In this study, after a median follow-up of 5 additional years, we evaluated subsequent IN incidence in these patients, submitted to surveillance colonoscopy. Patients without high-quality surveillance colonoscopy (with good bowel preparation and cecum intubation) using high-definition were excluded. Results One hundred and twenty-one patients were included. Nine had removed adenomas with low-grade dysplasia in the index colonoscopy. Now, in surveillance colonoscopy, we detected 9 (7.4%) IN: low-grade dysplasia was found in 8 (6.6%) patients and a colorectal adenocarcinoma in 1 (0.008%) patient. After multivariate analysis, IN was significantly associated with older age (68 vs. 52 years, p < 0.05) and higher disease duration (26 vs. 20 years, p < 0.05). No association was found between IN and previous detection of IN in screening colonoscopy sex, the CE or RB use in index colonoscopy, extent of disease, The presence of pseudopolyps, smoking habits, familial history of CRC or maintenance therapy for UC. Conclusion In this study, older patients and higher disease duration were associated with a higher risk of IN in surveillance colonoscopy.

P628 Histological remission does not offer additional benefit for ulcerative colitis patients in endoscopic remission

Abstract Background Histologic remission appears to be associated with positive outcomes in ulcerative colitis (UC) patients. However, it is not clear whether UC patients in endoscopic remission have additional benefit from achieving histologic remission. The objective of the study was to assess the relationship between time to relapse and histological activity among UC patients who are in endoscopic remission. Methods This was a retrospective observational study conducted at McMaster University Medical Centre in Hamilton, ON, Canada and University of Chicago Hospital, Chicago, IL. UC patients from an ongoing observational database who had achieved endoscopic remission (Mayo score 0) were included. Index colonoscopy was the first colonoscopy where Mayo 0 was achieved. These patients were classified based on their histologic activity: normal (no architectural changes or evidence of UC), inactive colitis (architectural changes but absence of acute inflammation), or active colitis (neutrophils in epithelium, crypt destruction, and/or erosions/ulcers). The primary outcome was time to relapse (defined as symptomatic flare with escalation of medical therapy, UC-related hospitalisation, colectomy, or development of colorectal cancer/dysplasia). Secondary outcomes included reasons for relapse and the association between other baseline variables and risk of relapse. A Cox proportional hazards model was used to evaluate the association of baseline factors with the outcome of relapse. Results 269 patients with UC and endoscopic remission were included in this study. According to a Kaplan–Meier survival curve analysis, there was no significant difference based on histologic activity with regards to time to relapse (log-rank p = 0.96)(See Figure). Patients with active colitis on histology did not have a higher relapse rate compared with those with inactive colitis (hazard ratio 1.11, p = 0.77), after adjustment for covariates. Older age, 5-aminosalicylate use, and disease location (both left-sided and pan-colitis) were found to be significantly associated with a lower rate of relapse. Symptomatic flare with an escalation of medical therapy accounted for the majority of relapses (80.4%). Conclusion Histologic remission did not impact time to relapse in UC patients who had achieved endoscopic remission. This suggests against targeting histologic remission in patients who have achieved endoscopic remission.

Causes of Post-Colonoscopy Colorectal Cancers Based on World Endoscopy Organization System of Analysis

Postcolonoscopy colorectal cancer (PCCRC) is CRC diagnosed after a colonoscopy in which no cancer was found. A consensus article from the World Endoscopy Organization (WEO) proposed an approach for investigating and categorizing PCCRCs detected within 4 years of a colonoscopy. We aimed to identify cases of PCCRC and the factors that cause them, test the WEO system of categorization, quantify the proportion of avoidable PCCRCs, and propose a target rate for PCCRCs detected within 3 years of a colonoscopy that did not detect CRC. We performed a retrospective analysis of 107 PCCRCs identified at a single medical center in England from January 1, 2010, through December 31, 2017 using coding and endoscopy data. For each case, we reviewed clinical, pathology, radiology, and endoscopy findings. Using the WEO recommendations, we performed a root-cause analysis of each case, categorizing lesions as follows: possible missed lesion, prior examination adequate; possible missed lesion, prior examination inadequate; detected lesion, not resected; or likely incomplete resection of previously identified lesion. We determined whether PCCRCs could be attributed to the colonoscopist for technical or decision-making reasons, and whether the PCCRC was avoidable or unavoidable, based on the WEO categorization and size of tumor. The endoscopy reporting system provided performance data forindividual endoscopists. Of the PCCRCs identified, 43% were in high-risk patients (those with inflammatory bowel disease, previous CRC, previous multiple large polyps, or hereditary cancer syndromes) and 66% were located distal to the hepatic flexure. There was no correlation between postcolonoscopy colorectal tumor size and time to diagnosis after index colonoscopy. Bowel preparation was poor in 19% of index colonoscopies, and only 36% of complete colonoscopies had adequate photodocumentation of completion. Development of 73% of PCCRCs was determined to be affected by technical endoscopic factors, 17% of PCCRCs by administrative factors (follow-up procedures delayed/not booked by administrative staff), and 27% of PCCRCs by decision-making factors. Twenty-seven percent of PCCRCs were categorized as possible missed lesion, prior examination adequate; 58% as possible missed lesion, prior examination inadequate; 8% as detected lesion, not resected; and 7% as incomplete resection of previously observed lesion; 89% were deemed to be avoidable. In a retrospective analysis of PCCRCs, using the WEO system of categorization, we found 43% to occur in high-risk patients; this might be reduced with more vigilant surveillance. Measures are needed to reduce technical, decision-making, and administrative factors. We found that 89% of PCCRCs may be avoidable. If half of avoidable PCCRCs could be prevented, the target rate of 2% for the PCCRC-3y (cancer diagnosed between 6 and 36 months after index colonoscopy) benchmark would be achievable.

Parthenolide ameliorates colon inflammation through regulating Treg/Th17 balance in a gut microbiota-dependent manner.

Inflammatory bowel disease (IBD) is a global health problem in which gut microbiota dysbiosis plays an important pathogenic role. However, the current drugs for IBD treatment are far from optimal. Previous researches indicated that parthenolide (PTL) had not only anti-cancer properties but also strong anti-inflammatory activities.Rationale: To investigate the protective effect of PTL on colon inflammation and demonstrate the underlying gut microbiota-dependent mechanism.Methods: Colon inflammation severity in mouse model was measured by body weight change, mortality, colon length, disease activity index (DAI) score, H&E staining and colonoscopy evaluation. Gut microbiota alteration and short-chain fatty acids (SCFAs) production were analyzed through 16S rRNA sequencing and targeted metabolomics. Luminex cytokine microarray and Enzyme-linked immunosorbent assay (ELISA) were conducted to measure the colon cytokines profile. The frequency of immune cells in lamina propria (LP) and spleen were phenotyped by flow cytometry.Results: The PTL-treated mice showed significantly relieved colon inflammation, as evidenced by a reduction in body weight loss, survival rate, shortening of colon length, DAI score, histology score and colonoscopy score. Notably, when the gut microbiota was depleted using antibiotic cocktails, the protective effect of PTL on colon inflammation disappeared. PTL treatment downregulated the level of proinflammatory cytokines, including IL-1β, TNF-α, IL-6, and IL-17A and upregulated the immunosuppressive cytokine IL-10 in colon tissue. 16S rRNA sequencing indicated that PTL-treated mice exhibited much more abundant gut microbial diversity and flora composition. Targeted metabolomics analysis manifested the increased SCFAs production in PTL-treated mice. Additionally, PTL administration selectively upregulated the frequency of colonic regulatory T (Treg) cells as well as downregulated the ratio of colonic T helper type 17 (Th17) cells, improving the Treg/Th17 balance to maintain intestinal homeostasis. Gut microbiota depletion and fecal microbiota transplantation (FMT) was performed to confirm this gut microbiota-dependent mechanism.Conclusions: PTL ameliorated colon inflammation in a gut microbiota-dependent manner. The underlying protective mechanism was associated with the improved Treg/Th17 balance in intestinal mucosa mediated through the increased microbiota-derived SCFAs production. Collectively, our results demonstrated the role of PTL as a potential gut microbiota modulator to prevent and treat IBD.

Histological Markers of Clinical Relapse in Endoscopically Quiescent Ulcerative Colitis.

In ulcerative colitis (UC) patients who have achieved mucosal healing, active microscopic colonic mucosal inflammation is commonly observed. We aimed to assess the association between histological activity and disease relapse in endoscopically quiescent UC. Ulcerative colitis patients with endoscopically quiescent disease and ≥12 months of follow-up were included. Biopsies were reviewed for the presence of basal plasmacytosis (BPC) and active histological inflammation, defined as a Geboes score (GS) ≥3.2. Primary outcome measures were disease relapse at 18 months and time to first relapse after index colonoscopy. Seventy-six UC patients (51% male; mean age, 38.6 years; median follow-up [range], 75.2 [2-118] months) were included. Sixty-two percent had an endoscopic Mayo score of 0 at index colonoscopy. Basal plasmacytosis was present in 46% and active histological inflammation in 30% of subjects. Presence of BPC was associated with a significantly shorter time to disease relapse (P = 0.01). Active histological inflammation was significantly associated with clinical relapse at 18 months (P = 0.0005) and shorter time to clinical relapse (P = 0.0006). Multivariate analysis demonstrated active histological inflammation to be independently associated with clinical relapse at 18 months and time to clinical relapse. In endoscopically quiescent UC, active histological inflammation and the presence of BPC are adjunctive histological markers associated with increased likelihood of disease relapse. Although prospective studies are required, the presence of these histological markers should be a factor considered when making therapeutic decisions in UC.

Complete Resolution of Mucosal Neutrophils Associates With Improved Long-Term Clinical Outcomes of Patients With Ulcerative Colitis

We investigated correlations between histologic features of the colonic mucosa in patients with ulcerative colitis (UC) and clinical outcomes during a 3-year follow-up period. We obtained baseline biopsies from all colorectal segments (n = 889) from 281 patients with UC enrolled in a prospective study at a single center from 2009 through 2013. Biopsies were assessed in a blinded manner using validated histologic scoring systems (the Geboes score, Nancy histopathologic index, and Robarts histopathologic index). Clinical, endoscopic, and histologic data were collected and tested for correlations with systemic corticosteroid use, hospitalization, and colectomy within 3 years of the index colonoscopy. We found histologic evidence of UC activity (Geboes score ≥ 2B.1) in biopsies from 182 patients (65%) and endoscopic evidence of UC activity in 149 patients (53%) (substantial agreement, κ= 0.60). Histologic features of UC activity were associated with increased rates of systemic corticosteroid use, colectomy, and hospitalization in the entire cohort (P < .05 for all) and associated with increased rates of systemic corticosteroid use in an analysis limited to patients in endoscopic remission (P < .001). In patients in endoscopic remission, only histologic activity was independently associated with use of systemic corticosteroids (multivariate odds ratio, 6.34; 95% CI, 2.20-18.28; P = .001). Similar results were seen when the entire cohort was analyzed. Compared with patients without histologic evidence of UC activity, patients with only a small number of mucosal neutrophils still had higher rates of systemic corticosteroid use (P < .001). Histologic evidence of UC activity, including small numbers of neutrophils in the colonic mucosa, is the only factor independently associated with use of systemic corticosteroids. Complete resolution of neutrophil-associated inflammation should be a target for treatment of UC.

How to identify patients who are less likely to have metachronous neoplasms after a colon cancer: a predictive model.

Patients with prior colon cancer have increased risk of metachronous colorectal neoplasms; therefore, endoscopic surveillance is indicated. Current recommendations are not risk-stratified. We investigated predictive factors for colorectal neoplasms to build a model to spare colonoscopies for low-risk patients. This was a multicenter, retrospective study including patients who underwent surgery for colon cancer in 2001 - 2008 (derivation cohort) and 2009 - 2013 (validation cohort). A predictive model for neoplasm occurrence at second surveillance colonoscopy was developed and validated. 421 and 203 patients were included in derivation and validation cohort, respectively. At second surveillance colonoscopy, 112 (26.6 %) and 55 (27.1 %) patients had metachronous neoplasms in derivation and validation groups; three cancers were detected in the latter. History of left-sided colon cancer (OR 1.64, 95 %CI 1.02 - 2.64), ≥ 1 advanced adenoma at index colonoscopy (OR 1.90, 95 %CI 1.05 - 3.43), and ≥ 1 adenoma at first surveillance colonoscopy (OR 2.06, 95 %CI 1.29 - 3.27) were independently predictive of metachronous colorectal neoplasms at second surveillance colonoscopy. For patients without such risk factors, diagnostic accuracy parameters were: 89.3 % (95 %CI 82.0 %-94.3 %) and 78.2 % (95 %CI 65.0 %-88.2 %) sensitivity, and 28.5 % (95 %CI 23.5 %-33.9 %) and 33.8 % (95 %CI 26.2 %-42.0 %) specificity in derivation and validation group, respectively. No cancer would be missed. Patients with prior left-sided colon cancer or ≥ 1 advanced adenoma at index colonoscopy or ≥ 1 adenoma at first surveillance colonoscopy had a significantly higher risk of neoplasms at second surveillance colonoscopy; patients without such factors had much lower risk and could safely skip the second surveillance colonoscopy. A prospective, multicenter validation study is needed.

Coexistent adenoma and serrated polyps on index colonoscopy and the risk of metachronous advanced colorectal neoplasia.

Background and aims The family of serrated polyps (SP) includes hyperplastic polyps (HP), sessile serrated adenomas/polyps, and traditional serrated adenoma. We investigated whether SP synchronous with adenoma at index colonoscopy is associated with metachronous advanced colorectal neoplasia (CRN). Methods Patients with ≥ 1 adenoma on index colonoscopy and who had undergone a follow-up colonoscopy were included. The patients were divided into four groups according to the presence of SP and advanced adenoma (AA) on index colonoscopy (non-AA, non-AA + SP, AA, AA + SP). The cumulative incidence of metachronous advanced CRN at surveillance colonoscopy was compared between groups. Results Among a total of 2209 patients, the numbers of patients in the non-AA, non-AA + SP, AA, and AA + SP groups were 922, 441, 625, and 221, respectively. The cumulative incidence of metachronous advanced CRN was higher in patients in the AA + SP group than that in the AA group ( P <0.001), and there was no significant difference between the non-AA + SP group and the non-AA group ( P = 0.06). The cumulative incidence of metachronous advanced CRN at 3 years was 17.9 % [95 % confidence interval (CI) 8.0–27.6], 10.7 % [95 %CI 7.7–3.6], 3.5 % [95 %CI 1.3–5.6], and 3.4 % [95 %CI 2.0–4.7] in the AA + SP, AA, non-AA + SP, and non-AA group, respectively. In a multivariate analysis, overall SP [hazard ratio (HR) 2.24; 95 %CI 1.38–3.64, P = 0.001], proximal SP (HR 2.31; 95 %CI 1.32–4.08), and HP (HR 2.19; 95 %CI 1.35–3.57) were risk factors for metachronous advanced CRN in patients with AA on index colonoscopy. Conclusions Coexistent AA and SP on index colonoscopy significantly increased the risk of metachronous advanced CRN compared with AA alone. Further large prospective studies are needed to confirm whether more intensive follow-up improves outcomes in these high risk patients.

Young adults and metachronous neoplasia: risks for future advanced adenomas and large serrated polyps compared with older adults

Recent increases in colorectal cancer (CRC) incidence in adults younger than 50 years of age have led to more colonoscopies in this age group. As a result, there may be an increasing number of adults<50 years old with polyps detected. There is concern that younger adults may require closer follow-up. Our goal was to use data from the New Hampshire Colonoscopy Registry (NHCR) to examine the risk for metachronous advanced adenomas (AAs) and large (>1 cm) serrated polyps in younger versus older adults who return for a follow-up colonoscopy. Our cohort consisted of NHCR participants with at least 1 polyp on index examination and a follow-up colonoscopy at least 1 year after the index examination. Outcomes were the risks for metachronous AAs (adenomas≥1 cm, with villous elements or high-grade dysplasia, or CRC) and large (≥1 cm) serrated polyps. We present absolute risk and adjusted risks from a logistic regression model stratified by age at index colonoscopy (<40, 40-49, 50-59, and 60+ [reference]). Covariates included index findings, endoscopist adenoma detection rates, sex, smoking, body mass index, follow-up time (months), bowel preparation quality, and family history of CRC. In our sample of 12,380 adults, absolute risk for metachronous AA was lower for younger patients than for patients aged≥60. After adjusting for covariates, when comparing with the 60+ group (reference), the lowest risk was observed in those younger than 40 years (odds ratio, .19; 95% confidence interval, .05-.80). Of note, similar risks were observed in the 40 to 49 age group (odds ratio, .61; 95% confidence interval, .41-.92) and 50 to 59 age group (odds ratio, .71; 95% confidence interval, .58-.86). The risk for large metachronous serrated polyps was not associated with age. Younger adults aged<40 with index adenomas had a lower risk for metachronous AAs than those aged≥60. The 40- to 49-year age group was found to have metachronous risk similar to the 50- to 59-year age group, with both less than the≥60 age group. These data suggest that current surveillance interval guidelines for patients aged≥50 years may appropriately be used with younger adults.

Outcomes at follow-up of negative colonoscopy in average risk population: systematic review and meta-analysis

ObjectiveTo review and summarise the evidence on the prevalence of colorectal adenomas and cancers at a follow-up screening colonoscopy after negative index colonoscopy, stratified by interval between examinations and by...

Quality of Preoperative Colonoscopy Affects Missed Postoperative Adenoma Detection in Colorectal Cancer Patients.

Despite thorough preoperative screening, 19-30% of synchronous polyps or adenomas are detected after colon cancer surgery. Remnant synchronous lesions require additional colonoscopy procedures or surgery. To investigate factors of preoperative colonoscopy potentially affecting the detection of missed lesions in patients subjected to colorectal cancer surgery. Of 1147 colorectal cancer patients subjected to curative open or laparoscopic colectomy and colonoscopy at the Chungnam National University Hospital from January 2012 to December 2016, 518 patients underwent pre- and postoperative colonoscopy. The index colonoscopy was defined as the last preoperative endoscopy performed. We analyzed pre- and postoperative medical charts for colonoscopy and pathological data. The effects of patient, procedure, and tumor factors on the postoperative adenoma detection rate, advanced adenoma detection rate, and adenoma miss rate (AMR) were analyzed. The overall AMR was 25.7% (95% confidence interval, 22.2-29.8%). Comparing optimal and non-optimal bowel preparation groups, the latter had greater postoperative polyp missed rate (PMR), AMR (p < 0.01), and AAMR (p = 0.272). The optimal preparation group allowed identification of more synchronous adenomas than in the fair (OR 5.72) and poor (OR 11.39) preparation groups. On univariate analysis, patient age and left-sided colectomy (p < 0.01) influenced AMR. Multivariate analysis showed that age, preoperative bowel preparation, and left colon resection influenced postoperative AMR. A better quality of index colonoscopy had a positive effect on lowering the detection rate of postoperative adenoma. Older age and suboptimal bowel preparation at the index colonoscopy and left-sided colectomy had negative effects on lowering the postoperative AMR.

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.

244 Exogenous Insulin Therapy Increases the Risk of Advanced Colorectal Adenoma Among Patients With Type 2 Diabetes Mellitus

INTRODUCTION: Endogenous hyperinsulinemia increases the risk of colorectal cancer (CRC) among patients with type 2 diabetes mellitus (T2DM). Exogenous insulin therapy, used by 30% of T2DM patients, further increases systemic levels of insulin and has been shown to increase the risk of CRC in animal models. We sought to evaluate the effect of exogenous insulin therapy on the incidence of advanced adenoma in T2DM patients. METHODS: We conducted a retrospective cohort study among patients with T2DM aged 40–80 at a tertiary healthcare center. Among other inclusion/exclusion criteria (Figure 1), eligible patients must have undergone 2 rounds of colonoscopy examinations – a baseline colonoscopy and a follow-up (index) colonoscopy ≥1 year later. Primary outcome was incident advanced adenomas at index colonoscopy. Primary exposure was long-term (≥1 year) insulin therapy before index colonoscopy. Assuming α = 0.05, background advanced adenoma incidence of 5%, and prevalence of insulin therapy among T2DM of 20%, a cohort size of 865 would be required to have 90% power to detect a 7.5 percentage point increase in advanced adenoma incidence among long-term insulin users. Multivariable logistic regression was used to estimate the odds ratio (OR) and 95% confidence interval (CI). RESULTS: Among patients with ≥1 diagnostic code for DM and ≥2 colonoscopy procedure codes, we randomly selected 1,900 patients for chart review and identified 867 eligible patients (Figure 1). Except for BMI, baseline characteristics between short-term/non-insulin users versus long-term insulin users were not significantly different (Table 1). Characteristics of the baseline and index colonoscopies were similar between the two groups (Table 1). Incidence of advanced adenoma at index colonoscopy was higher among the long-term insulin users versus short-term/non-insulin users (20% versus 4.7%, chi2 P &lt; 0.001). Multivariable adjusted OR for advanced adenoma risk associated with long-term insulin use was 6.2 (95% CI: 3.4–11.3). Long-term insulin use was also associated with increased risk of having ≥3 adenomas (adjusted OR 2.8, 95% CI 1.4–5.4) and having ≥1 right-sided advanced adenoma (adjusted OR 6.9, 95% CI 3.5–13.8) at index colonoscopy. CONCLUSION: Chronic insulin therapy was associated with increased risk of advanced adenoma occurrence in T2DM patients. This novel observation is important for developing a risk-tailored approach to the use of colonoscopy in CRC screening/surveillance in patients with T2DM.

120 Microscopic Colitis and Risk of Colon Adenomas: A Multicenter Retrospective Cohort Study

INTRODUCTION: Microscopic colitis (MC) is a common cause of chronic watery diarrhea. Cross-sectional studies have suggested that patients with MC have a lower incidence of colon polyps compared to those without MC. However, existing literature is limited by a lack of longitudinal follow-up and the use of average-risk patients, rather than those with chronic diarrhea as controls. We aimed to further explore the association between MC and colon adenomas. METHODS: This retrospective cohort study included patients that underwent colonoscopy at Mayo Clinic (Rochester, MN) or Columbia University Medical Center (New York, NY) between 7/1/2006 and 12/31/2016. Consecutive cases with MC were identified using pathology databases at each center. Controls had chronic diarrhea, underwent colonoscopy, and did not have MC on biopsy. Cases and controls were matched 1:2 by age (±3 years), sex, and date of index colonoscopy (±6 months). Data was collected on demographics, tobacco and alcohol use, personal and family history of colon neoplasia, and presence of adenomas at the index or follow-up colonoscopies. RESULTS: The study included 376 patients with MC and 752 non-MC patients with chronic diarrhea. The median (range) age of patients was 64 (21, 88) years and 72% were female. Duration of follow-up was not significantly different between the 2 groups (total person years: cases 577, controls 972; P = 0.99) and 51 subjects had a new adenoma on follow-up. There were no significant differences in age, sex, alcohol use, family history of colon neoplasia, and personal history of inflammatory bowel disease between cases and controls. Patients with MC were more likely to be current tobacco users (10% vs. 6%, P = 0.02) and less likely to have a history of prior colon neoplasia (9% vs. 17%, P &lt; 0.001). Patients with MC were significantly less likely to have colon adenomas at the time of their index colonoscopy (5% vs. 12%; odds ratio 0.36; 95% CI 0.21, 0.60; P &lt; 0.001) after adjusting for tobacco use and history of prior lesions. However, when followed over time, there was no significant association between MC and risk of colon adenomas (Figure 1, P = 0.45) after adjusting for tobacco use, history of prior lesions, and presence of adenoma at index colonoscopy. CONCLUSION: Patients with MC are less likely to have colon adenomas at their index colonoscopy compared to those with chronic diarrhea without MC. However, when followed longitudinally, there appears to be no significant association between MC and risk of colon adenomas.

The association between progression of coronary artery calcium and colorectal adenoma: A retrospective follow-up study of asymptomatic Koreans.

The potential relationship between coronary artery calcium (CAC) and colorectal adenoma has been widely indicated. This study aimed to investigate the relationship between the risk of colorectal adenoma and CAC progression in asymptomatic Korean adults who underwent serial assessments by colonoscopy and CAC scan.A total of 754 asymptomatic participants, who had undergone serial CAC scans and colonoscopies for screening, were enrolled. Changes in CAC were assessed according to the absolute change between baseline and follow-up results. CAC progression was defined using Multi-Ethnic Study of Atherosclerosis method. Risk for adenoma at follow-up colonoscopy was determined using hazard ratio (HR) by Cox regression. The area under the receiver operating characteristic (ROC) curve was measured.The mean follow-up duration was 3.4 ± 2.5 years. CAC progression was found in 215 participants (28.5%). Participants with adenoma at index colonoscopy showed a higher rate of CAC progression than those without (38.8% vs 23.6%, P < .01). In participants with adenoma at index colonoscopy, CAC progression significantly increased the cumulative risk for adenoma at follow-up colonoscopy (HR = 1.48, 95% confidence interval [CI] 1.06-2.06, log-rank P = .021). In multivariate analysis, male sex (HR = 2.57, 95% CI 1.22-5.42, P = .013), ≥3 adenomas at index colonoscopy (HR = 2.60, 95% CI 1.16-5.85, P = .021), and CAC progression (HR = 2.74, 95% CI 1.48-5.08, P = .001) increased the risk of adenoma at follow-up colonoscopy. In participants without adenoma at index colonoscopy, neither baseline CAC presence nor CAC progression increased the risk of adenoma at follow-up colonoscopy. The interaction between CAC progression and adenoma at index colonoscopy was significant in multivariable model (P = .005). In the ROC analysis, AUC of CAC progression for adenoma at follow-up colonoscopy was 0.625 (95% CI 0.567-0.684, P < .001) in participants with adenoma at index colonoscopy.Participants with CAC progression, who are at high risk of coronary atherosclerosis, may need to be considered for follow-up evaluation of colorectal adenoma, especially those with adenoma at index colonoscopy.

278 Helicobacter pylori Infection History Is Not a Risk Factor for Metachronous Advanced Adenoma: 8 Years' Follow-Up Study

INTRODUCTION: There have been several studies suggesting the association between Helicobacter pylori. (H. pylori) infection and colorectal adenoma or cancer. However, this causal relationship is still controversial. Most atrophic gastritis (AG) is caused by H. pylori infection and can be used as surrogate marker of H. pylori infection history. On the other hand, advanced adenoma (adenoma more than 10 mm or high-grade dysplasia (HGD) or villous adenoma) has been used as surrogate marker for risk evaluation of colorectal adenocarcinoma. The aim of this study was to determine the association between H. pylori infection and post-colonoscopy advanced adenoma (PCAA). METHODS: A retrospective cohort study was conducted in a center of preventive medicine and affiliated tertiary referral center in Tokyo, Japan. Consecutive 3104 individuals had general health check-up including esophagogastroduodenoscopy (EGD) between April 2004 and July 2014 and underwent initial diagnostic or screening colonoscopy within six months after general health check-up. The patients with history of inflammatory bowel disease or colectomy or only index colonoscopy were excluded. Baseline data included age, gender, height, weight, smoking history, index colonoscopy findings (the number of adenoma, maximum size of adenoma, HGD, villous adenoma), and EGD findings (AG). To determine the longitudinal association between baseline AG and PCAA, we calculated Kaplan-Meier estimates within eight years' horizon and performed multivariate Cox proportional hazards regression. RESULTS: Mean age [SD] of 3104 patients was 55 [12] years-old and 2169 patients (70%) were male. Mean BMI [SD] was 23 [3.2]. 1188 (39%) patients were diagnosed with AG. At the index colonoscopy, 1310 patients (42%) were diagnosed with colorectal adenoma. The cumulative incidence [95%CI] of PCAA at 3, and 5 years in the patients with AG was 3% [2–5], and 8% [6–10], respectively. Crude hazard ratio (HR) [95% CI] of age, male gender, body mass index, current smoking, and AG was 1.03 [1.02–1.05], 1.35 [0.9–2.03], 1.04 [0.98–1.1], 1.5 [0.98–2.27], and 1.46 [1.02–2.1]. Adjusted HR [95% CI] of age, current smoking, AG was 1.03 [1.02–1.05], 1.6 [1.04–2.5], and 1.2 [0.85–1.8], respectively. CONCLUSION: Older age and current smoking were significant risk factors of PCAA, but AG was not. The association between AG (H. pylori infection history) and PCAA was confounded by age and current smoking. The causal relationship between H. pylori infection and PCAA was not supported by our study.

236 Young Adults With Adenomas: How Does Their Risk for Metachronous Advanced Adenomas Compare With Older Adults?

INTRODUCTION: Recent increases in colorectal cancer (CRC) incidence in adults less than 50 years of age have led to more colonoscopies in this age group. As a result, there is an increasing number of adults &lt;50 with adenomas detected. We used data from the New Hampshire Colonoscopy Registry (NHCR) to explore whether these younger adults with adenomas are at higher risk for future advanced findings than older patients, potentially requiring closer follow-up. METHODS: Our cohort was NHCR participants with at least one adenoma and/or serrated polyp on index exam and a follow-up colonoscopy at least 1 year after the index exam. Outcomes were the absolute and adjusted metachronous risks of advanced adenomas (AA: adenomas &gt;1 cm, with villous elements or high-grade dysplasia, or CRC) and large (&gt;1 cm) serrated polyps (SP). Incomplete exams and patients with IBD or genetic familial syndromes were excluded. We present absolute risk and adjusted risks from a logistic regression model stratified by age at index colonoscopy (&lt;40, 40–49, 50–59, and 60+ (ref)). Covariates include findings on previous and index colonoscopy, sex, smoking, body mass index (BMI), time to follow-up (months), bowel preparation quality, and family history of CRC. RESULTS: Time to follow-up did not vary with age in our sample of 10,116 adults (Table 1). Absolute risk for metachronous AA was lower for younger patients (P &lt; 0.0001) (Table 1), with the lowest risk in patients &lt;40, similar risks in the 40–49 and 50–59 groups, and highest risk in patients &gt;60. Adjusting for covariates did not change findings (P = 0.003). Because younger adults were less likely to have index AAs, we performed a sensitivity analysis, excluding index exams with AAs, and observed no changes in results (P = 0.003). The metachronous risk for large SPs was not significantly associated with age (Table 2). CONCLUSION: Younger adults with index adenomas have a lower risk for metachronous AAs than patients &gt;50. These data suggest that younger adults are not at higher risk for metachronous advanced neoplasia than older adults. The data also suggest that surveillance intervals recommended by current guidelines for adults &gt;50 years may be safe to apply to younger adults.