Proximal Adenomas Research Articles

Impact of advanced endoscopy training on colonoscopy quality and efficiency.

Few reports have detailed improvements in the quality of colonoscopies with continuous training post-fellowship completion. We examined the changes in colonoscopy performance among trainees during our advanced endoscopy training program. Screening or surveillance colonoscopies performed by 11 trainees who participated in our 3-year advanced endoscopy training program between April 2015 and March 2020 were retrospectively analyzed. Quality and efficiency metrics of colonoscopies were evaluated annually. Altogether, 297, 385, and 438 colonoscopies were enrolled in the first, second, and third training years, respectively. The mean insertion times were 8.6, 7.6, and 6.9 min in the first, second, and third training years, respectively, with significant improvement from the first to second year (p = 0.03) and from the first to third year (p < 0.01). The adenoma detection rate, proximal adenoma detection rate, and mean number of adenomas per patient exhibited a tendency to improve annually; however, the difference was not significant. Polypectomy efficiency was 10.5%, 11.2%, and 13.0%, with significant improvements from the first to third year (p < 0.01) and from the second to third year (p = 0.02). Insertion time and polypectomy efficiency showed significant improvements, especially among trainees experienced with <500 colonoscopies. Through our advanced endoscopy training program, there has been an improvement in the quality and efficiency of colonoscopy for trainees who have completed their fellowships, particularly those with <500 colonoscopies.

Impact of linked color imaging on the proximal adenoma miss rate: useful or not?

Impact of linked color imaging on the proximal adenoma miss rate: useful or not?

Impact of linked color imaging on the proximal adenoma miss rate: a multicenter tandem randomized controlled trial (the COCORICO trial).

Missed lesions are common during standard colonoscopy and are correlated with post-colonoscopy colorectal cancer. Contrast-enhanced technologies have recently been developed to improve polyp detection. We aimed to evaluate the impact of linked color imaging (LCI) on the proximal adenoma miss rate in routine colonoscopy. This national, multicenter, tandem, randomized trial compared the outcomes of colonoscopy with white-light imaging (WLI) versus LCI for polyp detection in the right colon. Two consecutive examinations of the right colon (upstream of the hepatic flexure) were made with WLI and LCI by the same operator. First-pass examination by WLI or LCI was randomized 1:1 after cecal intubation. According to statistical calculations, 10 endoscopy units had to include approximately 700 patients. The primary outcome was proximal adenoma miss rate. Secondary outcomes were the proximal miss rates for sessile serrated lesions (SSL), advanced adenomas, and polyps. 764 patients were included from 1 January 2020 to 22 December 2022, and 686 patients were randomized (345 WLI first vs. 341 LCI first). Both groups were comparable in terms of demographics and indications. The proximal adenoma miss rate was not significantly higher in the WLI-first group (36.7%) vs. the LCI-first group (31.8%) (estimated mean absolute difference: 4.9% [95%CI -5.2% to 15.0%], P = 0.34). There was also no significant difference in miss rates for SSLs, advanced adenomas, and polyps in the proximal colon. In contrast to previous data, this study does not support the benefit of LCI to the proximal adenoma miss rate in routine colonoscopy.

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.

Adenoma-Based Colonoscopy Quality Metrics for the 45–49 Years Old Military Screening Population

BACKGROUND AND AIMSWith the rising incidence of colorectal cancer in younger individuals, guidelines now recommend initiating average-risk screening at age 45 years. We sought to assess the impact of this younger screening population on established and emerging colonoscopy quality metrics. METHODSWe compared all well-described lesion detection rates by colonic segment removed during initial, average-risk screening colonoscopies in the San Antonio Market military healthcare network from July 2019 to September 2022. RESULTSA total of 2165 colonoscopies met the inclusion criteria, with 755 (34.9%) colonoscopies performed on patients aged 45-49 years old. The detection rates for adenomas, proximal adenomas, advanced adenomas, and adenomas per colonoscopy were lower in the 45-49 years old group (33.4%, 18.7%, 3.8%, and 0.58, respectively) compared with the 50-75 years old group (42.7%, 24.2%, 7.7%, and 1.11, respectively; all P < 0.05). There was no difference in serrated polyp detection in the 45-49 years old group (11.5%) compared with the 50-75 years old group (12.5%; P = 0.287). There were no differences in withdrawal times, cecal intubation rates, or bowel preparation adequacy across age groups. CONCLUSIONIn our screening population, we found that adenoma-based colonoscopy quality metrics were significantly lower in the 45-49 years old population compared to the traditional screening age cohort, while there was no difference in serrated polyp detection. Endoscopists should anticipate a small decline in colonoscopy quality benchmarks as the screening population becomes younger, although these results require validation through multicenter, prospective monitoring.

Role of Artificial Intelligence in Colonoscopy Detection of Advanced Neoplasias : A Randomized Trial.

The role of computer-aided detection in identifying advanced colorectal neoplasia is unknown. To evaluate the contribution of computer-aided detection to colonoscopic detection of advanced colorectal neoplasias as well as adenomas, serrated polyps, and nonpolypoid and right-sided lesions. Multicenter, parallel, randomized controlled trial. (ClinicalTrials.gov: NCT04673136). Spanish colorectal cancer screening program. 3213 persons with a positive fecal immunochemical test. Enrollees were randomly assigned to colonoscopy with or without computer-aided detection. Advanced colorectal neoplasia was defined as advanced adenoma and/or advanced serrated polyp. The 2 comparison groups showed no significant difference in advanced colorectal neoplasia detection rate (34.8% with intervention vs. 34.6% for controls; adjusted risk ratio [aRR], 1.01 [95% CI, 0.92 to 1.10]) or the mean number of advanced colorectal neoplasias detected per colonoscopy (0.54 [SD, 0.95] with intervention vs. 0.52 [SD, 0.95] for controls; adjusted rate ratio, 1.04 [99.9% CI, 0.88 to 1.22]). Adenoma detection rate also did not differ (64.2% with intervention vs. 62.0% for controls; aRR, 1.06 [99.9% CI, 0.91 to 1.23]). Computer-aided detection increased the mean number of nonpolypoid lesions (0.56 [SD, 1.25] vs. 0.47 [SD, 1.18] for controls; adjusted rate ratio, 1.19 [99.9% CI, 1.01 to 1.41]), proximal adenomas (0.94 [SD, 1.62] vs. 0.81 [SD, 1.52] for controls; adjusted rate ratio, 1.17 [99.9% CI, 1.03 to 1.33]), and lesions of 5 mm or smaller (polyps in general and adenomas and serrated lesions in particular) detected per colonoscopy. The high adenoma detection rate in the control group may limit the generalizability of the findings to endoscopists with low detection rates. Computer-aided detection did not improve colonoscopic identification of advanced colorectal neoplasias. Medtronic.

Blue-light imaging or narrow-band imaging for proximal colonic lesions: a prospective randomized tandem colonoscopy study

Blue-light imaging (BLI) is a new image-enhanced endoscopy with a wavelength filter similar to narrow-band imaging (NBI). We compared the 2 with white-light imaging (WLI) on proximal colonic lesion detection and miss rates. In this 3-arm prospective randomized study with tandem examination of the proximal colon, we enrolled patients aged≥40 years. Eligible patients were randomized in 1:1:1 ratio to receive BLI, NBI, or WLI during the first withdrawal from the proximal colon. The second withdrawal was performed using WLI in all patients. Primary outcomes were proximal polyp (pPDRs) and adenoma (pADRs) detection rates. Secondary outcomes were miss rates of proximal lesions found on tandem examination. Of 901 patients included (mean age, 64.7 years; 52.9% men), 48.1% underwent colonoscopy for screening or surveillance. The corresponding pPDRs of the BLI, NBI, and WLI groups were 45.8%, 41.6, and 36.6%, whereas the corresponding pADRs were 36.6%, 33.8%, and 28.3%. There was a significant difference in pPDR and pADR between BLI and WLI groups (difference, 9.2% [95% confidence interval {CI}, 3.3-16.9] and 8.3% [95% CI, 2.7-15.9]) and between NBI and WLI groups (difference, 5.0% [95% CI, 1.4-12.9] and 5.6% [95% CI, 2.1-13.3]). Proximal adenoma miss rates were significantly lower with BLI (19.4%) than with WLI (27.4%; difference, -8.0%; 95% CI, -15.8 to -.1) but not between NBI (27.2%) and WLI. Both BLI and NBI were superior to WLI on detecting proximal colonic lesions, but only BLI had lower proximal adenoma miss rates than WLI. (Clinical trial registration number: NCT03696992.).

PREVALENCE OF SERRATED POLYPS AND THEIR ASSOCIATION WITH SYNCHRONOUS COLORECTAL ADVANCED ADENOMAS.

•This study revealed a similar prevalence of clinically significant serrated polyps and advanced adenomas among patients who underwent colonoscopy. •Multivariate analysis demonstrated an association between clinically significant serrated polyps and synchronous advanced adenomas, though the strength of this association was stronger for proximal advanced adenomas. •Large serrated polyps and sessile serrated adenomas were associated with proximal advanced adenomas. Background - Serrated lesions are the precursors of up to one-third of colorectal cancer (CRC) cases and share molecular and epidemiological features with interval CRC. Previous studies have reported wide variation in serrated polyp prevalence and diverse magnitude of its relationship with synchronous advanced adenomas.Objective - Describe the prevalence of serrated polyps and evaluate their association with synchronous advanced adenomas. Methods - The study is a retrospective analysis of 1208 colonoscopies performed in patients aged 45 to 75, predominantly for CRC screening. Data on the prevalence of serrated polyps subsets and advanced adenomas were collected, and multivariate analysis were performed to identify the association between serrated polyps and synchronous advanced adenomas. Results - The prevalence of clinically significant serrated polyps (CSSP), large serrated polyps (LSP), and sessile serrated adenomas (SSA) were 11.3%, 6%, and 3.7%. CSSP were associated with synchronous advanced adenomas (OR 2.121, 95%CI 1.321-3.406), regardless of proximal (OR 2.966, 95%CI 1.701-5.170) or distal (OR 1.945, 95%CI 1.081-3.499) location, while LSP (OR 2.872, 95%CI 1.425-5.787) and SSA (OR 5.032, 95%CI 2.395-10.576) were associated with proximal advanced adenomas. Conclusion - The prevalence of CSSP and advanced adenomas were alike. CSSP is a risk factor for advanced adenomas, and the strength of this association is stronger for proximal advanced adenomas. LSP and SSA are associated with proximal advanced adenomas.

Risk factor analysis of malignant adenomas detected during colonoscopy.

Several studies have shown that colorectal adenomas are the most important precancerous lesions. The colonoscopic identification of groups with the high risk of malignant colorectal adenomas remains a controversial issue for clinicians. To evaluate the basic characteristics of colorectal adenomas with malignancy risk using high-grade dysplasia (HGD) as an alternative marker for malignant transformation. Data from Shanghai General Hospital between January 2017 and December 2021 were retrospectively analyzed. The primary outcome was the incidence of HGD in adenomas, which was used as a surrogate marker for the risk of malignancy. Odds ratios (ORs) for the HGD rate in adenomas were analyzed in relation to adenoma-related factors. A total of 9,646 patients identified with polyps during 57,445 screening colonoscopies were included in the study. Patients with flat polyps, sessile polyps, and pedunculated polyps represented 27.3% (N = 2,638), 42.7% (N = 4,114), and 30.0% (N = 2,894) of the total number, respectively. HGD was found in 2.41% (N = 97), 0.92% (N = 24), and 3.51% (N = 98) of sessile adenomas, flat adenomas, and pedunculated adenomas, respectively (P < 0.001). Multivariable logistic regression showed that polyp size (P < 0.001) but not shape (P > 0.8), was an independent predictor of HGD. Contrast to the diameter ≤1 cm, the OR value for diameters 1-2, 2-3, and >3 cm was 13.9, 49.3, and 161.6, respectively. The HGD incidence also increased in multiple adenomas (>3 vs. >1, ORs 1.582) and distal adenomas (distal vs. proximal adenomas, OR 2.252). Adenoma morphology (pedunculated vs. flat) was statistically significant in univariate analysis but not when size was included in the multivariate analysis. Besides, the incidence of HGD was also significantly higher in older patients (>64 vs. <50 years old, OR = 2.129). Sex (P = 0.681) was not statistically significant. All these associations were statistically significant (P < 0.05). The malignant potential of polyps is mostly affected by their size but not by their shape. In addition, distal location, multiple adenomas, and advanced age were also correlated with malignant transformation.

Reporting of Adenoma Detection by Segment: A Proposed New Quality Metric for Colonoscopy

Background and AimsThe adenoma detection rate (ADR), is a key quality metric for colonoscopy, but it might fail to measure differences in adenoma detection in different parts of the colon. Because many post-colonoscopy cancers arise in the proximal colon, differences in the ADR of proximal vs distal adenomas could be clinically important. Our aim was to determine the feasibility of measuring ADR for both the proximal and distal colon and to understand differences based on age, sex, and race. MethodsWe queried a large claims database (Health Care Service Corporation) to screen colonoscopies from 2016-2018 to determine the location and pathology of detected polyps. We measured the ADR in both the proximal (P-ADR) and distal (D-ADR) colon to determine differences in the ratio of P-ADR vs D-ADR by age, sex, and race. ResultsThe cohort included 93,163 women and 89,132 men. A progressive increase in both P-ADR and D-ADR occurs with advancing age, with the P-ADR/D-ADR ratio rising from 1.2 in patients under 40 years of age to 2.65 in patients age 75 and older, in both men and women. This ratio is affected by the experience of the endoscopist. A higher volume of procedures is directly related to higher polyp detection, specifically the P-ADR. ConclusionAs age advances, there is an increasing predominance of proximal adenomas relative to distal adenomas in both men and women, in all races. With appropriate coding, it is feasible to measure the ADR for the proximal and distal colon. Measurement of P-ADR could be an important new quality metric.

Computer-assisted detection versus conventional colonoscopy for proximal colonic lesions: a multicenter, randomized, tandem-colonoscopy study

Computer-assisted detection (CADe) is a promising technologic advance that enhances adenoma detection during colonoscopy. However, the role of CADe in reducing missed colonic lesions is uncertain. The aim of this study was to determine the miss rates of proximal colonic lesions by CADe and conventional colonoscopy. This was a prospective, multicenter, randomized, tandem-colonoscopy study conducted in 3 Asian centers. Patients were randomized to receive CADe or conventional white-light colonoscopy during the first withdrawal of the proximal colon (cecum to splenic flexure), immediately followed by tandem examination of the proximal colon with white light in both groups. The primary outcome was adenoma/polyp miss rate, which was defined as any adenoma/polyp detected during the second examination. Of 223 patients (48.6% men; median age, 63 years) enrolled, 7 patients did not have tandem examination, leaving 108 patients in each group. There was no difference in the miss rate for proximal adenomas (CADe vs conventional: 20.0% vs 14.0%, P= .07) and polyps (26.7% vs 19.6%, P= .06). The CADe group, however, had significantly higher proximal polyp (58.0% vs 46.7%, P= .03) and adenoma (44.7% vs 34.6%, P= .04) detection rates than the conventional group. The mean number of proximal polyps and adenomas detected per patient during the first examination was also significantly higher in the CADe group (polyp: 1.20 vs .86, P= .03; adenoma, .91 vs .61, P= .03). Subgroup analysis showed that CADe enhanced proximal adenoma detection in patients with fair bowel preparation, shorter withdrawal time, and endoscopists with lower adenoma detection rate. This multicenter trial from Asia confirmed that CADe can further enhance proximal adenoma and polyp detection but may not be able to reduce the number of missed proximal colonic lesions. (Clinical trial registration number: NCT04294355.).

IS SURVIVIN LEVEL IDENTICAL BETWEEN ADENOMAS OF PROXIMAL AND DISTAL COLON?

Objectives: Considerable differences are known between proximal and distal colon, these include embryological, anatomical, histological, biochemical, and physiological characteristics. Above mentioned distinctions may influence development of variable clinico-morphological entities. Multifunctional antiapoptotic protein survivin participates in regulation of cell cycle, apoptotic cascades, and stimulates angiogenesis. Material and methods: We assessed immunohistochemically expression pattern of antiapoptotic protein survivin in a panel of 243 colon adenomas to determine its association with colon localization. In each section, subcellular compartmentalization of survivin and intensity of immunoreaction were evaluated. Results: Survivin was expressed in 190 cases (78.2%). Statistical analysis confirmed a significant correlation of subcellular survivin compartmentalization and intensity of immunoreaction with colon localization of adenomas. Conclusions: Taking into account unique features of survivin, its expression pattern in proximally sided adenomas, and distinctions between left and right colon, we suppose that survivin level may contribute to higher proliferative phenotype of proximal adenomas.

Site-specific Performance of ColonView (CV) Fecal Immunochemical Test (FIT) With Differences Between Proximal and Distal Colorectal Adenoma.

The aim of this study was to assess the diagnostic accuracy (DA) of a ColonView (CV) test in proximal versus distal colorectal adenoma (pCRA versus dCRA). The colorectal neoplasia (CRN) screening cohort included 5,090 individuals and 506/5,090 (10%) were eligible for the study. Finally, only 127/506 were included in the CRA analysis and hierarchical summary ROC (HSROC) curves were used to show the pooled overall DA of visually analyzed (VA) and automatically analyzed (AA) techniques in pCRA and dCRA detection. The overall specificity (Sp) of the AA technique for the pCRA and dCRA endpoint was 46% and 43%, respectively. The most sensitive AA test in pCRA patients showed 76% sensitivity (Se) versus 58% Se in dCRA patients. In the HSROC analysis, area under the curve (AUC) values were as follows: i) VA in pCRA: AUC=0.503, ii) AA in pCRA: AUC=0.560, iii) VA in dCRA: AUC=0.552 and iv) AA in dCRA: AUC=0.486. In Roccomp analysis, the statistically significant AUC values were available between VA and AA reading modes in pCRA (p=0.044) and in AA reading between pCRA and dCRA (p=0.024). As compared with the CRC endpoint, the DA value of the CV test is far inferior for the CRA endpoint, as determined by the AUC values.

Does i-scan improve adenoma detection rate compared to high-definition colonoscopy? A systematic review and meta-analysis.

Background and study aims Recent studies evaluated the impact of i-scan in improving the adenoma detection rate (ADR) compared to high-definition (HD) colonoscopy. We aimed to systematically review and analyze the impact of this technique. Methods A thorough search of the following databases was undertaken: PubMed/Medline, EMBASE, Cochrane and Web of Science. Full-text RCTs and cohort studies directly comparing i-scan and HD colonoscopy were deemed eligible for inclusion. Dichotomous outcomes were pooled and compared using random effects model and DerSimonian-Laird approach. For each outcome, relative risk (RR), 95 % confidence interval (CI), and P value was generated. P < 0.05 was considered statistically significant. Results A total of five studies with six arms were included in this analysis. A total of 2620 patients (mean age 58.6 ± 7.2 years and female proportion 44.8 %) completed the study and were included in our analysis. ADR was significantly higher with any i-scan (RR: 1.20, [CI: 1.06–1.34], P = 0.003) compared to HD colonoscopy. Subgroup analysis demonstrated that ADR was significantly higher using i-scan with surface and contrast enhancement only (RR: 1.25, [CI: 1.07–1.47], P = 0.004). Conclusions i-scan has the potential to increase ADR using the surface and contrast enhancement method. Future studies evaluating other outcomes of interest such as proximal adenomas and serrated lesions are warranted.

Risk of developing metachronous colorectal neoplasia after the resection of proximal versus distal adenomas.

Current post-polypectomy guidelines do not consider adenoma location. We compared the risk of metachronous colorectal neoplasia (CRN) according to adenoma location. We collected data from 9710 patients who underwent follow-up colonoscopy after adenoma removal. Patients were classified according to baseline adenoma location: distal only (n=4665), proximal only (n=3827), and both sides (n=1218). The risk of metachronous CRN in patients with proximal only adenomas was higher than that in those with distal only adenomas (adjusted hazard ratio [aHR]=1.12, 95% confidence interval [CI]=1.04-1.21), while the risk of metachronous advanced CRN (ACRN) was not different between the two groups. Among patients aged <50 years, the risk of metachronous CRN in those with proximal only non-advanced adenomas (NAAs) was higher than that in those with only distal NAAs, while among patients aged ≥50 years, the risk in those with proximal only advanced adenomas (AAs) was higher than that in those with distal only AAs. However, the risk of metachronous ACRN did not differ based on adenoma location in patients aged <50 and ≥50 years. Proximal adenoma was associated with an increased risk of metachronous CRN, but not with an increased risk of metachronous ACRN, supporting the current guidelines recommending the same surveillance interval for distal and proximal adenoma without discrimination by adenoma location.

Comparative Efficacy of Endoscopic Assist Devices on Colonic Adenoma Detection: A Systematic Review With Network Meta-analysis.

Numerous endoscopic assist devices exist, yet data surrounding their comparative efficacy is lacking. We conducted a systematic review with network meta-analysis to determine the comparative efficacy of endoscopic assist devices on colonic adenoma detection. A systematic search was performed using multiple electronic databases through July 2020, to identify all randomized controlled trials and dual-arm observational studies compared with either other endoscopic assist devices and/or standard colonoscopy. The primary outcome was adenoma detection rate (ADR). Secondary outcomes included polyp detection rate (PDR), serrated adenoma detection rate (SADR), right-sided adenoma detection rate (RADR), and proximal adenoma detection rate (PADR). Fifty-seven studies (31,051 patients) met inclusion criteria and were analyzed. Network meta-analysis identified an enhanced ADR among (clear) cap [odds ratio (OR): 2.69, 95% confidence interval (CI): 1.45-4.99], endocuff, (OR: 4.95, 95% CI: 3.15-7.78), and endoring (OR: 3.68, 95% CI: 1.47-9.20)-with no significant difference amongst any particular device. Similar findings for PDR were also seen. Enhanced SADR was identified for endocuff (OR: 9.43) and endoring (OR: 4.06) compared with standard colonoscopy. Enhanced RADR (OR: 5.36) and PADR (OR: 3.78) were only identified for endocuff. Endocuff comparatively demonstrated the greatest ADR, PDR, and SADR, but this was not significant when compared with the other assist devices. Subgroup analysis of randomized controlled trials identified enhanced PDR and ADR for both cap and endocuff. Endoscopic assist devices displayed increased ADR and PDR as compared with standard colonoscopy and thus should be widely adopted. A nonsignificant trend was seen toward higher efficacy for the endocuff device.

Circulating nucleosomes for detection of colorectal cancer and high-risk advanced adenomas.

169 Background: Detection and treatment of early colorectal cancer (CRC) or advanced adenomas (AA) is the key for superior outcomes and fecal immunochemical testing (FIT)-based screening has proven effective in reducing CRC death and the risk of advanced-stage CRC but the discrepancy in the effectiveness was observed between proximal and distal cancers. On the other hand, false-positive results of FIT with 60 % of negative colonoscopy is another concern, considering the burden to the screening participants and the healthcare providers. A blood-based test as an alternative or supplement to FIT has the potential to concurrently enhance the detection of high-risk neoplasms and identify individuals at risk who should then be referred to colonoscopy. We investigated the levels of circulating free nucleosomes containing different epigenetic modifications in patients referred for colonoscopy. Methods: 10mls whole blood was obtained from 520 asymptomatic patients prior to colonoscopy at National Taiwan University Hospital. Patients were classified into 5 groups based on their colonoscopy reports: (i) patient with CRC (n = 33), (ii) patients with AA (n = 123, including 18 with AA &gt; 2cm); (iii) patients with non-AA (n = 168); (iv) patients with non-neoplastic polyps (n = 30); (vi) healthy controls with no endoscopic lesion (n = 166). Plasma samples were analyzed for nucleosome levels using 7 different quantitative immunoassays (Nu.Q assays; Belgian Volition SRL, Belgium) targeting H3.1-nucleosomes or different histone modifications (H3K27Me3-, H3K36Me3-, H3K9Me3-, H3K14Ac-, H3K27Ac- or H3R8Cit-nucleosomes). All study subjects were asked to collect a stool sample at home within 48-hours before the colonoscopy. The fecal samples were assayed with the Eiken OC-SENSOR FIT kit (Eiken Chemical Co., Ltd., Tokyo, Japan) for all study subjects. Results: At a cut-off of 20µg/g feces, the FIT test showed a sensitivity of 92,9% at 17.5% specificity for CRC +AA vs. Controls. All the CRC patients and 83.3% of the high-risk AA (&gt; 2cm) patients were FIT positive. A combination of 2 Nu.Q biomarkers: H3K27Me3 and H3R8Cit with FIT in a logistic regression model showed improved sensitivity of 95% at 20.6% specificity allowing the detection of all CRC patients and 94.3% of AA patients including all the high-risk adenomas. The FIT test detected 46 out of 55 proximal adenomas whereas the combined model could detect 50 proximal adenomas including 3 proximal AA &gt; 2cm not being detected by FIT (p &lt; 0.05). The same combination would reduce unnecessary colonoscopies by 21.8% of the control and 23.3% of the non-neoplastic polyps subgroups compared to 17.5% and 6.7%, respectively with the FIT test alone. Conclusions: Our results indicate that H3K27Me3 and H3R8Cit-nucleosome levels in combination with FIT could improve the detection of proximal high-risk AA and could also provide a non-invasive method to reduce unnecessary colonoscopy.

Racism Is a Modifiable Risk Factor: Relationships Among Race, Ethnicity, and Colorectal Cancer Outcomes

Racism Is a Modifiable Risk Factor: Relationships Among Race, Ethnicity, and Colorectal Cancer Outcomes

Preinvasive Colorectal Lesions of African Americans Display an Immunosuppressive Signature Compared to Caucasian Americans.

BackgroundAfrican Americans (AAs) have higher colorectal cancer (CRC) incidence and mortality rate than Caucasian Americans (CAs). Recent studies suggest that immune responses within CRCs contribute to the disparities. If racially distinct immune signatures are present in the early phases of carcinogenesis, they could be used to develop interventions to prevent or slow disease.MethodsWe selected a convenience sample of 95 patients (48 CAs, 47 AAs) with preinvasive colorectal adenomas from the surgical pathology laboratory at the Medical University of South Carolina. Using immunofluorescent-conjugated antibodies on tissue slides from the lesions, we quantified specific immune cell populations: mast cells (CD117+), Th17 cells (CD4+RORC+), and NK cell ligand (MICA/B) and inflammatory cytokines, including IL-6, IL-17A, and IFN-γ. We compared the mean density counts (MDCs) and density rate ratios (RR) and 95% CI of immune markers between AAs to CAs using negative binomial regression analysis. We adjusted our models for age, sex, clinicopathologic characteristics (histology, location, dysplasia), and batch.ResultsWe observed no racial differences in age or sex at the baseline endoscopic exam. AAs compared to CAs had a higher prevalence of proximal adenomas (66% vs. 40%) and a lower prevalence of rectal adenomas (11% vs. 23%) (p =0.04) but no other differences in pathologic characteristics. In age, sex, and batch adjusted models, AAs vs. CAs had lower RRs for cells labeled with IFNγ (RR 0.50 (95% CI 0.32-0.81); p=0.004) and NK cell ligand (RR 0.67 (0.43-1.04); p=0.07). In models adjusted for age, sex, and clinicopathologic variables, AAs had reduced RRs relative to CAs for CD4 (p=0.02), NK cell ligands (p=0.01), Th17 (p=0.005), mast cells (p=0.04) and IFN-γ (p< 0.0001).ConclusionsOverall, the lower RRs in AAs vs. CAs suggests reduced effector response capacity and an immunosuppressive (‘cold’) tumor environment. Our results also highlight the importance of colonic location of adenoma in influencing these differences; the reduced immune responses in AAs relative to CAs may indicate impaired immune surveillance in early carcinogenesis. Future studies are needed to understand the role of risk factors (such as obesity) in influencing differences in immune responses by race.

Impact of simethicone on bowel cleansing during colonoscopy in Chinese patients.

BACKGROUNDFour-liter polyethylene glycol (PEG) solutions are effective for bowel cleansing, but their large volume might hinder patient compliance. Due to the unique features of Asians, 4 L PEG might be a suboptimal bowel preparation in predominantly ethnically Asian countries. In view of this, a balance should be achieved between the volume and effectiveness. The ideal bowel cleansing regimen for a colonoscopy has yet to be determined in a Chinese population.AIMTo compare the cleansing efficacy of 3 L PEG plus simethicone with 4 L PEG.METHODSA total of 291 patients were randomly allocated to two groups: Group 1 (n = 145) received 4 L split-dose PEG (4-P); group 2 (n = 146) received 3 L split-dose PEG plus simethicone (3-PS). Bowel-cleansing efficacy was evaluated by endoscopists using the Boston bowel preparation scale (BBPS) and the bubbles score.RESULTSAlthough there were no significant differences in the total BBPS score or the adequate rate of bowel preparation between the two groups, the BBPS score of the right-side colon was significantly higher in the 3-SP group (2.37 ± 0.54 vs 2.21 ± 0.78; P = 0.04). Moreover, the use of simethicone significantly reduced bubbles in all colon segments (P < 0.001). The mean withdrawal time was significantly shorter in the 3-PS group (8.8 ± 3.4 vs 9.6 ± 2.3; P = 0.02). Furthermore, significantly more proximal adenomas were detected in the 3-PS group (53.6% vs 45.7%; P = 0.03). In addition, the proportions of patients with nausea and bloating were significantly lower in the 3-SP group (P < 0.01 for both). More patients in the 3-PS group expressed willingness to repeat the bowel preparation (87.7% vs 76.6%, P = 0.01).CONCLUSIONThree-liter PEG shows satisfactory bowel cleansing despite the decrease in dosage, and addition of simethicone with better bubble elimination and enhanced patient acceptance offers excellent potential impact on the detection of proximal adenomas in Chinese patients.