Nonpolypoid Lesions Research Articles

Efficacy of Per-oral Methylene Blue Formulation for Screening Colonoscopy

Topically applied methylene blue dye chromoendoscopy is effective in improving detection of colorectal neoplasia. When combined with a pH- and time-dependent multimatrix structure, a per-oral methylene blue formulation (MB-MMX) can be delivered directly to the colorectal mucosa. We performed a phase 3 study of 1205 patients scheduled for colorectal cancer screening or surveillance colonoscopies (50-75 years old) at 20 sites in Europe and the United States, from December 2013 through October 2016. Patients were randomly assigned to groups given 200 mg MB-MMX, placebo, or 100 mg MB-MMX (ratio of 2:2:1). The 100-mg MB-MMX group was included for masking purposes. MB-MMX and placebo tablets were administered with a 4-L polyethylene glycol-based bowel preparation. The patients then underwent colonoscopy by an experienced endoscopist with centralized double-reading. The primary endpoint was the proportion of patients with 1 adenoma or carcinoma (adenoma detection rate [ADR]). We calculated odds ratios (ORs) and 95% confidence intervals (CIs) for differences in detection between the 200-mg MB-MMX and placebo groups. False-positive (resection rate for non-neoplastic polyps) and adverse events were assessed as secondary endpoints. The ADR was higher for the MB-MMX group (273 of 485 patients, 56.29%) than the placebo group (229 of 479 patients, 47.81%) (OR 1.46; 95% CI 1.09-1.96). The proportion of patients with nonpolypoid lesions was higher in the MB-MMX group (213 of 485 patients, 43.92%) than the placebo group (168 of 479 patients, 35.07%) (OR 1.66; 95% CI 1.21-2.26). The proportion of patients with adenomas ≤5 mm was higher in the MB-MMX group (180 of 485 patients, 37.11%) than the placebo group (148 of 479 patients, 30.90%) (OR 1.36; 95% CI 1.01-1.83), but there was no difference between groups in detection of polypoid or larger lesions. The false-positive rate did not differ significantly between groups (83 [23.31%] of 356 patients with non-neoplastic lesions in the MB-MMX vs 97 [29.75%] of 326 patients with non-neoplastic lesions in the placebo group). Overall, 0.7% of patients had severe adverse events but there was no significant difference between groups. In a phase 3 trial of patients undergoing screening or surveillance colonoscopies, we found MB-MMX led to an absolute 8.5% increase in ADR, compared with placebo, without increasing the removal of non-neoplastic lesions. Clinicaltrials.gov no: NCT01694966.

Crypts With Corrupted Shapes in Non-polypoid Adenomas.

Colonic crypts with normal epithelial lining exhibiting corrupted shapes (NECS) have been previously found beneath the adenomatous tissue of polypoid conventional adenomas, in both rats and humans. To assess the frequency of NECS in non-polypoid colonic flat adenomas (FAs) and lateral-spreading adenomas (LSAs). Histological hematoxylin and eosin-stained sections from 51 non-polypoid colonic adenomas were scrutinized over a 10-mm field of vision (FOV). FAs were regarded lesions encompassed within the FOV and LSAs as those surpassing that limit. The NECS/mm ratio was calculated in individual lesions as the number of NECS beneath the adenomatous tissue, divided by the length (mm) of the FA and LSA. Out of the 51 non-polypoid adenomas, 27 were FAs and the remaining 24 LSAs. All 51 non-polypoid lesions were tubular adenomas. The mean number of NECS in FAs was 6.29 (range=2-10) and in LSAs was 15.29 (range=7-41) (p<0.05). On the other hand, the mean NECS/mm ratio in FAs was 0.94 (range=0.50-2.00) and in LSAs was 0.92 (range=0.40-2.93). Thus, no essential differences in the number of NECS/mm was found between FA and LSA. The accretion of NECS below the neoplastic canopy of FA and LSA contrasts with the rare occurrence of NECS in normal colonic mucosa. This finding emerges as a previously unaddressed major event, an event that might play an important role in the histogenesis of non-polypoid adenomas of the colon.

Metabolic syndrome is a risk factor for colorectal adenoma and cancer: a study in a White population using the harmonized criteria.

Background:Metabolic syndrome (MetS) has been associated with colorectal adenomas and cancer. However, MetS definitions have changed over time, leading to a heterogeneity of patients included in previous studies and a substantial inextensibility of observations across time or eastern and western populations. Our aim was to evaluate the association of ‘harmonized’ criteria-defined MetS and its individual components with colorectal neoplasia and cancer in a western population.Methods:In this multicenter, cross-sectional study, we prospectively evaluated consecutive outpatients who underwent open-access colonoscopy over a 3-month period. MetS was diagnosed according to the 2009 ‘harmonized’ criteria.Results:Out of 5707 patients enrolled, we found 213 cancers (3.7%), 1614 polyps (28.3%), 240 nonpolypoid lesions (4.2%), 95 laterally spreading tumors (1.6%). Polyps presented histological low-grade dysplasia in 72.9% of samples, while in 9.8%, high-grade dysplasia or in situ carcinoma was present; dysplasia rates for nonpolypoid lesions were 66.2% (low-grade) and 2.9% (high-grade/in situ carcinoma), while for laterally spreading tumors, 29.6% and 37%, respectively. Overall, MetS prevalence was 41.6%. MetS correlated with both adenomas [odds ratio (OR): 1.76, 95% confidence interval (CI) 1.54–2.00] and cancer (OR: 1.92, 95% CI 1.42–2.58). MetS was the only risk factor for such colonic lesions in subjects younger than 50 years. For all colonic neoplasia, we found MetS and not its individual components to be significantly associated.Conclusions:MetS is risk factor for cancer and adenoma in Whites, especially when younger than 50 years. MetS patients might be considered as a high-risk population also in colorectal cancer screening programs.

Current strategies for malignant pedunculated colorectal polyps.

Despite significant advances in imaging techniques, the incidence of colorectal cancer has been increasing in recent years, with many cases still being diagnosed in advanced stages. Early detection and accurate staging remain the main factors that lead to a decrease in the cost and invasiveness of the curative techniques, significantly improving the outcome. However, the diagnosis of pedunculated early colorectal malignancy remains a current challenge. Data on the management of pedunculated cancer precursors, apart from data on nonpolypoid lesions, are still limited. An adequate technique for complete resection, which provides the best long-term outcome, is mandatory for curative intent. In this context, a discussion regarding the diagnosis of malignancy of pedunculated polyps, separate from non-pedunculated variants, is necessary. The purpose of this review is to provide a critical review of the most recent literature reporting the different features of malignant pedunculated colorectal polyps, including diagnosis and management strategies.

Efficacy of autofluorescence imaging for flat neoplasm detection: a multicenter randomized controlled trial (A-FLAT trial)

Colorectal flat (nonpolypoid) lesions can be overlooked during colonoscopy. This study evaluated the efficacy of updated autofluorescence imaging (AFI) for detecting colorectal flat neoplasms. This was a prospective, multicenter, randomized controlled trial in 9 Japanese tertiary institutions. Patients undergoing colonoscopy because of positive fecal immunochemical tests, surveillance after polypectomy, or investigation of minor symptoms were enrolled and randomly assigned to either the white-light imaging (WLI) or the AFI group. Primary outcome measurement was number of flat neoplasms per patient. From November 2015 to June 2017, 817 patients were enrolled. After excluding 15 patients, 802 were finally analyzed (404, WLI; 398, AFI). Patients' backgrounds (sex, age, indication of colonoscopy, experience of endoscopists) and quality of colonoscopy (bowel preparation, sedative use, cecal insertion rate, insertion and withdrawal time) were not different between groups. Number of flat neoplasms in each patient was significantly higher in the AFI than in the WLI group (.87 [95% confidence interval [CI], .78-.97] vs .53 [95% CI, .46-.61]), whereas overall and polypoid neoplasm detection was not significantly different betweenthe groups (1.33 [95% CI, 1.22-1.45] vs 1.14 [95% CI, 1.03-1.24], .46 [95% CI, .40-.53] vs .60 [95% CI, .53-.68]). Flat neoplasms were more frequently detected in the right-sided colon with AFI (.61 [95% CI, .54-.70] vs .30 [95% CI, .25-.36]) but not in the left-sided colon and rectum (.26 [95% CI, .21-.32] vs .23 [95% CI, .19-.28]). Updated AFI improves the detection of flat colorectal neoplasms in the right-sided colon compared with WLI. (Clinical trial registration number: UMIN000019355.).

Incidence and distribution of advanced colorectal adenomas in patients undergoing colonoscopy for screening, surveillance, and symptoms.

PurposeThe aim of the study was to determine the frequency and distribution of advanced colorectal adenomas (ACAs) in Chinese population.MethodsThe patients who were referred to receive a colonoscopy were divided into three subgroups of screening, surveillance, and symptomatic, and then they were selected based on their indications. The symptomatic subgroup was further broken down into the alarm and non-alarm categories. The location and morphology of all colorectal lesions were both investigated and recorded.ResultsThere were significantly more patients with ACAs in the symptomatic subgroup compared to the screening or surveillance subgroup (11.0% vs 4.1%, P<0.001; 11.0% vs 4.6%, P=0.006). No differences were found in the ACA frequency between the alarm and non-alarm categories (11.7% vs 9.7%, P=0.056). One observation was that in the symptomatic subgroup, distal lesions were more likely to contain ACAs than proximal ones (OR 1.50, 95% CI 1.05–2.15, P=0.024). It was also noted that nonpolypoid lesions had significantly higher amounts of ACAs in the symptomatic subgroup (OR 2.09, 95% CI 1.48–2.94, P<0.001) than the other groups.ConclusionThe incidence of ACAs was higher in patients undergoing a colonoscopy due to their symptoms, compared to the incidence in those who underwent the procedure for screening or surveillance purposes. Additionally, more attention should be focused on distal and nonpolypoid lesions to improve the detection rate of ACAs.

Outcomes of Endoscopic Resections of Large Laterally Spreading Colorectal Lesions in Inflammatory Bowel Disease: a Single United Kingdom Center Experience.

The SCENIC consensus statement recommends endoscopic resection of all visible dysplasia in inflammatory bowel disease, but patients with large or complex lesions may still be advised to have colectomy. This article presents outcomes for large nonpolypoid resections associated with colitis at our institution. Data including demographics, clinical history, lesion characteristics, method of resection, and postresection surveillance were collected prospectively in patients with visible lesions within colitic mucosa from January 2011 to November 2016. Resection techniques included endoscopic mucosal resection , endoscopic submucosal dissection (ESD), and hybrid ESD. Surveillance with magnification chromoendoscopy was performed at 3 months, 1-year postresection, and annually thereafter. Fifteen lesions satisfied the inclusion criteria in 15 patients. Mean lesion size was 48.3+/-21.7 (20-90) mm. All lesions were non-polypoid with distinct margins and no ulceration. 73% lesions were scarred of which 64% had undergone prior instrumentation. En bloc resection was achieved in n=6. Presumed endoscopic diagnosis was confirmed histopathologically in all resected lesions. One case of perforation and another with bleeding were both managed endoscopically. Median follow-up was 28 months (12-35) with no recurrence. This cohort series demonstrates that endoscopic resection of large non-polypoid lesions associated with colitis is feasible and safe using an array of resection methods supporting the role of advanced endoscopic therapeutics for the management of colitis associated dysplasia in a western tertiary endoscopic center.

Non-polypoid Colorectal Lesions Are More Likely to Harbor Cancer Compared to Polypoid Lesions: A Systematic Review and Meta-Analysis

Introduction: Flat (Paris type 0- II) polyps also known as non-polypoid colorectal lesions (NPCRL) are easily missed and more likely to be associated with advanced histology compared to polypoid lesions -Paris type 0-I (PCRL). Presence of advanced histology among these lesions is reported variably and no pooled rates are known. Our aim was to report pooled rates of advanced histology including cancer in NPCRL compared to PCRL. Methods: Electronic database search was conducted in Embase, medline, google scholar and Cochrane for eligible studies. Inclusion criteria were studies reporting both NPCRL and PCRL found during colonoscopy and data on advanced histology and cancer. Studies that did not have information on both NPCRL and PCRL in the same study were excluded. Advanced adenoma (High grade dysplasia, tubulo villous, villous adenoma) was taken as surrogate marker for advanced histology in the analysis. The outcomes reported were pooled rate of cancer detected in NPCRL versus PCRL and pooled rate of detection of advanced histology in both groups. Outcomes were reported in form of risk ratios (RR) with 95% confidence intervals (CI) with P-values. Statistical analysis was performed using Review manager vs 5.3 software. Results: Of 547 articles reviewed, 15 studies were eligible for analysis. There were a total of 58,764 patients with a mean age of 61 years and 56% of them were males. There were a total of 9,588 NPCRL compared to 35,105 PCRL. Indications for colonoscopy were: screening 47%, surveillance 16% and diagnostic 38%. Cancer was detected in 0.95% of NPCRL (72 of 7595) and 0.90% of PCRL (258 of 28736). The NPCRL were likely to harbor cancer compared to PCRL as shown with pooled RR of 2.1 (95% CI 1.043-4.358, I2 72%) and these results were statistically significant (P<0.001). Total number of advanced histology detected in NPCRL and PCRL was 14% (1348 of 9588) and 13.6% (4582 of 33739), respectively. NPCRL were likely to be having advanced histology compared to PCRL as pooled RR was 1.4 (95%CI 0.973-2.150) but the results were not statistically significant (p =0.068). Conclusion: Non-polypoid colorectal lesions are more likely to harbor cancer compared to polypoid lesions.Figure: Forest plot of inclusion studies of detection of cancer among NPCRL vs PCRL group (I2 72%).

Optimizing the quality of endoscopy in inflammatory bowel disease: focus on surveillance and management of colorectal dysplasia using interactive image- and video-based teaching

Varying recommendations regarding the detection and management of dysplasia can lead to uncertainty and may impede the uptake of strategies that could improve surveillance in patients with inflammatory bowel disease (IBD). An educational event was held to assist in disseminating the recently published Surveillance for Colorectal Endoscopic Neoplasia Detection and Management in Inflammatory Bowel Disease Patients: International Consensus Recommendations (SCENIC). Specialists in IBD and endoscopy led the Optimizing Quality of Endoscopy in IBD course. The American Society for Gastrointestinal Endoscopy (ASGE) organized the course, and the Crohn's and Colitis Foundation of America (CCFA) provided endorsement. One was held in March 2015 at the ASGE Institute for Training and Technology in Chicago, Illinois, and the second in September 2016 preceding the ASGE Endofest in Chandler, Arizona. The program included interactive case-based discussions and didactic presentations on topics including the rationale and current approach of surveillance in IBD; endoscopic characterization and nomenclature of active and quiescent disease; detection of dysplasia during IBD surveillance; role of image-enhanced endoscopy in IBD surveillance, with a focus on chromoendoscopy technique; and management of dysplasia in IBD. Participants were surveyed before and after the course to assess their perspectives and practice. Eighteen presenters or panel members and approximately 92 IBD and endoscopist physician leaders attended the meeting. Most attendees were aged 30 to 49 years (88.1%), had been in practice less than 10 years (89.7%), were from academic medical centers (90.7%), and spent >50% of their time caring for patients with IBD (59.7%). Recommended quality improvements for endoscopy in IBD included the use of endoscopic scoring systems to describe disease activity, the use of a modified Paris classification to characterize visible dysplastic lesions (polypoid, nonpolypoid with description of presence of ulcer and distinct or indistinct borders), the use of chromoendoscopy for dysplasia detection, and the endoscopic removal of visible dysplastic lesions. In the follow-up survey, participants were asked to indicate whether they had changed their practice as a result of attending the course. Ninety-three percent (93%) indicated they had changed their practice. For dysplasia detection, the use of chromoendoscopy increased: 51.7% of respondents reported using chromoendoscopy in most surveillance colonoscopies compared with 34.3% before the course. For dysplasia management, the use of EMR increased for polypoid and nonpolypoid lesions 10 to 20mm in size; and the referral of dysplastic lesions 20mm or larger that appeared endoscopically resectable shifted toward removal by an experienced endoscopist. Evidence-based advances in endoscopy have occurred in the characterization and nomenclature of active and quiescent disease, polypoid and nonpolypoid dysplasia in IBD, and in the detection and management of dysplasia in colonic IBD. Implementation of updated guidelines and recommendations into clinical practice may be facilitated by interactive image- and video-based courses on the topic.

Mo1135 Outcomes of Endoscopic Resections of Large Non-Polypoid Lesions Inflammatory Bowel Disease: A Single United Kingdom Centre Experience

Mo1135 Outcomes of Endoscopic Resections of Large Non-Polypoid Lesions Inflammatory Bowel Disease: A Single United Kingdom Centre Experience

P535 Outcomes of endoscopic resections of large non-polypoid lesions inflammatory bowel disease: a single United Kingdom centre experience

Background: Patients with colitis carry an increased risk for the development of dysplasia. The SCENIC consensus statement recommends endoscopic resection (ER) of all visible dysplasia [1]. Due to technical challenges and limited ER experience in the West of large colitis associated non-polypoid (NP) lesions, such patients are often subjected to colectomy. The King's Institute of Therapeutic Endoscopy (KITE) is a tertiary centre for assessment and ER of challenging colorectal polyps. Here we present the largest single centre case series of large colitis associated NP resections. Methods: Patient demographics, clinical history, lesion characteristics, method of ER and surveillance were collected prospectively in patients undergoing ER of NP lesions 20mm within known distribution of colitis from January 2011 to November 2016. ER techniques included endoscopic mucosal resection, endoscopic submucosal dissection (ESD) and hybrid ESD. Surveillance of resection site with magnification chromendoscopy (mCE) was performed at 3 months (m) with pan colonic mCE at 1-year post ER and annually thereafter. Results: Thirteen lesions satisfied the inclusion criteria in n=13. Patient demographics/clinical data are presented in Table 1. Table 1. Baseline characteristics Mean lesion size was 47.3±22.4 (20–90)mm. All lesions were NP with distinct margins and no ulceration. High frequency mini-probe ultrasound confirmed intramucosal lesions in n=5 where surface pattern was distorted by inflammation. En bloc resection was achieved in n=6. 69% lesions were deeply scarred of which 66% experienced prior instrumentation. ER of 1 lesion was abandoned due to intense fibrosis. Macroscopic evidence of complete ER was achieved in all remaining cases. Endoscopic diagnosis of pre-cancerous lesions of less than 1000μm submucosal invasion was confirmed histologically in 100% of ERs. Complete excision was confirmed in all en bloc resections. A single case of perforation and 1 with delayed minor bleeding were both managed endoscopically. Mortality/hospital admission within 30 days post ER was 0%. Median follow up was 28m (12–35) with no recurrence. Alternative site dysplasia was detected in n=2. All lesions were <20mm and underwent ER. Two patients were referred for colectomy due to a concomitant diagnosis of neuroendocrine tumour and the second with alternate site advanced dysplasia. Conclusions: This case series demonstrates that ER of large colitis associated NP lesions is feasible using an array of methods, safe and has good long term outcomes in a western tertiary endoscopic centre.

Value of histomorphometric tumour thickness and smoothelin for conventional m-classification in early oesophageal adenocarcinoma.

AIMTo test the validity of tumour thickness measurement in distinguishing between the different infiltration depths, especially when the duplication of muscularis mucosae cannot be demarcated clearly.METHODSWe re-evaluated 100 completely embedded Barrett’s adenocarcinomas regarding m-classification, maximum tumour thickness, and muscularis mucosae duplication. For validation, smoothelin staining was performed on a subset of cases.RESULTSThe m1-, m2- and m3-classified adenocarcinomas showed a significant lower tumour thickness compared to the m4- and sm1-classified lesions (P < 0.001). Smoothelin staining determined a clear muscularis mucosae duplication in 64% of the tested samples and enabled the differentiation of the two layers in diffuse and merged splits.CONCLUSIONTumour thickness in early oesophageal adenocarcinoma significantly correlates with the depth of infiltration and demonstrates its worth as an accurate pT classification in non-polypoid lesions. We created a new algorithm, which combines histomorphology with morphometric analyses. It is noteworthy that it facilitates the assessment of mucosal vs submucosal infiltration depth. The smoothelin staining strengthened our results of the tumour thickness evaluation and can be used in cases of doubt.

Hyoscine butylbromide for colorectal polyp detection: prospective, randomized, placebo-controlled trial

OBJECTIVES:The removal of pre-malignant colorectal lesions prevents cancer. Hyoscine has been proposed as a means of improving diagnosis by reducing colonic movements. The aim of this study was to analyze whether this anti-spasmodic enhances the detection of pre-malignant colorectal lesions.METHODS:In a randomized, double-blinded fashion patients received hyoscine or a saline solution in all consecutive colonoscopies in which the cecum was reached. Lesions were analysed with respect to number, size, location, histology and capillary pattern.RESULTS:A total of 440 colonoscopies were randomized. The overall polyp detection rate (PDR) and the adenoma detection rate (ADR) were 65.2% and 49.3%, respectively. In the hyoscine group, non-polypoid lesions were detected significantly more often (p=0.01). In the placebo group 281 lesions were diagnosed (202 adenomas) and in the hyoscine group 282 lesions were detected (189 adenomas) (p=0.23). The PDR and ADR were similar between the placebo and hyoscine groups (64% vs 66% and 50% vs 47%, respectively). No differences were observed between the two groups in the advanced-ADR or advanced neoplasia detection rate, as well the mean numbers of polyps, adenomas, advanced adenomas and advanced neoplasias detected per patient. The administration of hyoscine also did not improve the diagnostic accuracy of digital chromoendoscopy. The presence of adenomatous polyps in the right colon was detected significantly more frequently in the hyoscine group (OR 5.41 95% CI 2.7 - 11; p<0.01 vs OR 2.3 95% CI 1.1 - 4.6; p=0.02).CONCLUSION:The use of hyoscine before beginning the withdrawal of the colonoscope does not seem to enhance the PDR and the ADR.

Efficacy Evaluation of SAVE for the Diagnosis of Superficial Neoplastic Lesion.

The detection of non-polypoid superficial neoplastic lesions using current standard of white light endoscopy surveillance and random biopsy is associated with high miss rate. The subtle changes in mucosa caused by the flat and depressed neoplasms often go undetected and do not qualify for further investigation, e.g., biopsy and resection, thus increasing the risk of cancer advancement. This paper presents a screening tool named the saliency-aided visual enhancement (SAVE) method, with an objective of highlighting abnormalities in endoscopic images to detect early lesions. SAVE is a hybrid system combining image enhancement and saliency detection. The method provides both qualitative enhancement and quantitative suspicion index for endoscopic image regions. A study to evaluate the efficacy of SAVE to localize superficial neoplastic lesion was performed. Experimental results for average overlap index >0.7 indicated that SAVE was successful to localize the lesion areas. The area under the receiver-operating characteristic curve obtained for SAVE was 94.91%. A very high sensitivity (100%) was achieved with a moderate specificity (65.45%). Visual inspection showed a comparable performance of SAVE with chromoendoscopy to highlight mucosal irregularities. This paper suggests that SAVE could be a potential screening tool that can substitute the application of burdensome chromoendoscopy technique. SAVE method, as a simple, easy-to-use, highly sensitive, and consistent red flag technology, will be useful for early detection of neoplasm in clinical applications.

The Immune Landscapes of Polypoid and Nonpolypoid Precancerous Colorectal Lesions.

Little is known about the immunoediting process in precancerous lesions. We explored this aspect of benign colorectal adenomas with a descriptive analysis of the immune pathways and immune cells whose regulation is linked to the morphology and size of these lesions. Two series of polypoid and nonpolypoid colorectal adenomas were used in this study: 1) 84 samples (42 lesions, each with matched samples of normal mucosa) whose gene expression data were used to quantify the tumor morphology- and size-related dysregulation of immune pathways collected in the Molecular Signature Database, using Gene Set Enrichment Analysis; 2) 40 other lesions examined with immunohistochemistry to quantify the presence of immune cells in the stromal compartment. In the analysis of transcriptomic data, 429 immune pathways displayed significant differential regulation in neoplasms of different morphology and size. Most pathways were significantly upregulated or downregulated in polypoid lesions versus nonpolypoid lesions (regardless of size). Differential pathway regulation associated with lesion size was observed only in polypoid neoplasms. These findings were mirrored by tissue immunostaining with CD4, CD8, FOXP3, MHC-I, CD68, and CD163 antibodies: stromal immune cell counts (mainly T lymphocytes and macrophages) were significantly higher in polypoid lesions. Certain markers displayed significant size-related differences regardless of lesion morphology. Multivariate analysis of variance showed that the marker panel clearly discriminated between precancerous lesions of different morphologies and sizes. Statistical analysis of immunostained cell counts fully support the results of the transcriptomic data analysis: the density of infiltration of most immune cells in the stroma of polypoid precancerous lesions was significantly higher than that observed in nonpolypoid lesions. Large neoplasms also have more immune cells in their stroma than small lesions. Immunoediting in precancerous colorectal tumors may vary with lesion morphology and stage of development, and this variability could influence a given lesion’s trajectory to cancer.

Su1660 Endoscopic Resection for Large, Non-Polypoid Neoplastic Lesions of the Colon: EMR vs. ESD

Su1660 Endoscopic Resection for Large, Non-Polypoid Neoplastic Lesions of the Colon: EMR vs. ESD

Factors Associated With Recurrence of Advanced Colorectal Adenoma After Endoscopic Resection.

Studies have identified risk factors for recurrence of advanced colorectal adenoma (ACA) after polypectomy, but the relative importance and interaction of these risk factors, and their potential impact on surveillance recommendations, are unclear. We aimed to develop a model to identify ACA features associated with risk of recurrence after polypectomy. In a retrospective study, we collected data from 3360 patients who underwent colonoscopy with polypectomy at University of Foggia from 2004 through 2008 and identified 746 patients with1017 ACAs. We performed recursive partitioning analysis to identify factors associated with recurrence of ACA within 3 years after polypectomy. Median ACA size was 16 mm (range, 8-34 mm) and median number was 1.5 (range, 1-2). Pedunculated, sessile, and nonpolypoid lesions accounted for 41.3%, 39.4%, and 19.3% of ACAs detected, respectively. Factors independently associated with local recurrence of ACA and metachronous distant polyps within 3 years after polypectomy included size and number of ACAs and grade of dysplasia. The recurrence rate was 4.2% in patients with a single ACA ≤15 mm without high-grade dysplasia (HGD), 21.3% in patients with HGD ≤15 mm, ACA withoutHGD >15 mm, or multiple ACAs without HGD ≤15 mm, and 57.9% in patients with HGD>15 mm. In this retrospective analysis of 746 patients with ACA who underwent polypectomy and surveillance colonoscopy within 3 years, the recurrence rate was highest in those with HGD ≥15 mm. These patients might benefit from more intensive surveillance, whereas patients with a single ACA without HGD ≤15 mm are at lower risk for and could be considered for longer follow-up intervals.

How to deal with large colorectal polyps: snare, endoscopic mucosal resection, and endoscopic submucosal dissection; resect or refer?

The importance of accurate polyp detection and removal is paramount to preventing colon cancer. Resection of large polyps can be challenging to the endoscopist based on their size, shape, or location. Large polyps have the potential of harboring malignancy and a higher risk of complications with resection. Careful assessment of each lesion and meticulous resection using the appropriate tools and techniques is essential. Over the last 15 years, the development of endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD) techniques has presented the endoscopist with the opportunity to manage patients with large and flat lesions thereby avoiding the need for surgery. However, these techniques are complex and require extensive knowledge and skill in the use of various devices to resect a lesion completely and manage bleeding and perforation associated with these procedures. Large colon polyps manifest as either polypoid or nonpolypoid (flat) lesions. Polypoid lesions, especially those with pedicles, are removed with snare resection, whereas flat lesions may require the use of EMR or ESD. Resection of large polyps (>1 cm) requires additional tools and techniques to ensure safe and complete resection. We will discuss our approach to dealing with large colorectal polyps: snare, EMR, and ESD; resect or refer?

Morphological Characteristics and Location of Missed, Advanced Colorectal Neoplasms after Colonoscopy.

This retrospective study aimed to clarify the clinical characteristics of advanced colorectal neoplasms after colonoscopy, likely to have been missed on the previous colonoscopy. We reviewed a total of 5,768 consecutive colonoscopies performed from April 2010 to September 2013 in 4,841 patients, and analyzed advanced colorectal neoplasms after colonoscopy, particularly focusing on their morphological characteristics and locations, as compared with primary lesions, defined as lesions detected in their first colonoscopy or in a subsequent colonoscopy >5 years after the previous one. Of the 5,768 examinations, 922 advanced neoplasms (including 217 cancers with ≥T2) were detected, and 167 lesions (18.1%) were diagnosed within 5 years after a previous colonoscopy (post-colonoscopy advanced neoplasms). The incidence of right-sided lesions in the post-colonoscopy advanced neoplasms (48.5%, 81/167) was significantly higher than in the primary lesions (34.0%, 257/755; p <0.001). We excluded 217 cancers with ≥T2 from the morphological analysis to characterize early-stage post-colonoscopy advanced neoplasms. The incidence of non-polypoid lesions in the post-colonoscopy advanced neoplasms (25.6%, 41/160) was significantly higher than that in the primary lesions (12.3%, 67/545; p <0.001). These findings suggest that extra attention should be paid to non-polypoid, right-sided advanced colorectal neoplasms during screening and surveillance colonoscopy. J. Med. Invest. 63: 163-170, August, 2016.

OC-080 Low-grade dysplasia in ulcerative colitis: risk factors associated with progression to high-grade dysplasia or colorectal cancer: Abstract OC-080 Table 1

Introduction The aim of this study was to identify risk factors associated with development of high-grade dysplasia (HGD) or colorectal cancer (CRC) in ulcerative colitis (UC) patients diagnosed with low-grade dysplasia (LGD). Method Patients with histologically confirmed extensive UC who were diagnosed with LGD between 1993 and 2012 were identified and followed up to 1 st January 2013. Data on patient demographics, endoscopic and histological variables at the time of the first LGD episode were collected and correlated with progression to HGD or CRC, our primary outcome measure. Time to event analysis was performed using Cox-proportional hazards methods. Results A total of 172 patients were followed for median of 48 months (interquartile range (IQR), 15–87) who underwent 707 follow-up colonoscopies (median, 4; IQR, 2–6) after the initial LGD episode. Overall, 33 patients developed HGD or CRC (19.1%) during study period. Table 1shows variables significantly associated with progression to HGD/CRC on univariate analysis. At multivariate level, only macroscopically non-polypoid (HR, 8.6; 95% CI, 3.0–24.8; p p = 0 .02) lesions, lesions ≥1 cm in size (HR, 3.8; 95% CI, 1.5–13.4; p = 0 .01), and a previous history of indefinite for dysplasia diagnosis (HR, 2.8; 95% CI, 1.2–6.5; P = 0 .01) remained significant contributory factors for developing HGD/CRC. The detection rate for non-polypoid lesions was significantly higher with chromoendoscopy (15.8%) compared with white-light endoscopy (7.8%; p Conclusion The chromoendoscopy was superior at detecting non-polypoid lesions compared with the white-light endoscopy. Lesions that are large (≥1 cm), non-polypoid, and endoscopically invisible or preceded by “indefinite for dysplasia” diagnosis are independent risk factors for the development of HGD/CRC. Disclosure of interest None Declared.