Proximal Adenoma Detection 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.

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.).

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.

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.

Endocuff-assisted versus Cap-assisted Colonoscopy in Increasing Adenoma Detection Rate. A Meta-analysis.

Several add-on devices have been developed to increase rates of colon adenoma detection. We aimed to compare the endocuff-assisted colonoscopy with cap-assisted colonoscopy through a pairwise meta-analysis of randomized trials. We searched the PubMed/Medline and Embase database through March 2020 and identified 6 randomized controlled trials (comprising 2,027 patients). The primary outcome was adenoma detection rate; secondary outcomes included sessile serrated adenoma detection rate, mean adenoma per colonoscopy, cecal intubation rate and time to reach cecum. Safety data were also analyzed. We performed pairwise meta-analysis through a random effects model and expressed data as risk ratio and 95% confidence interval. Overall, pooled adenoma detection rate was 48.1% (39.3-56.8%) with endocuff and 40.5% (30.4- 50.6%; risk ratio 1.14, 0.96-1.35) with cap. Proximal adenoma detection rate was 45.7% (36.8-54.7%) and 24% (17-45.1%) with endocuff and cap, respectively (risk ratio 2.04, 0.93-4.49), whereas endocuff outperformed cap-assisted colonoscopy in detecting diminutive (≤ 5 mm) adenomas (risk ratio 2.74, 1.53-4.90) and in terms of mean adenoma per colonoscopy (mean difference 0.31, 0.05 -0.57; p=0.02). Sessile serrated adenoma detection rate (risk ratio 1.36, 0.72-2.59), cecal intubation rate (risk ratio 0.99, 0.98-1.00), and time to reach cecum (6.87 min versus 6.87 min) were similar between the two groups. No serious adverse event was observed. Endocuff-assisted colonoscopy seems to provide a higher adenoma detection rate as compared to cap-assisted colonoscopy, in particular concerning smaller diminutive polyps.

How to increase proximal adenoma detection rate: a meta-analysis comparing water exchange, water immersion and air/CO2 insufflation methods for colonoscopy.

BackgroundRecent meta-analyses have demonstrated a higher adenoma detection rate using the water exchange method (WE), compared to water immersion (WI) and air/CO2 insufflation (ACI). Proximal adenomas have a high miss rate owing to their location and appearance. We performed a systematic review and meta-analysis of studies comparing the WE and WI methods to the ACI method, with a primary focus on proximal adenoma detection rate.MethodsThe following databases were searched for our systematic review: Medline, Embase, Cochrane Library, CINAHL, and Web of Sciences. We included both randomized controlled trials and cohort studies. The primary outcome was proximal adenoma detection rate, and secondary outcomes were right adenoma detection rate and cecal intubation rate.ResultsA total of 12 studies (17 arms) with 5660 patients (2260 ACI, 2281 WE, and 1119 WI) were included. A higher proximal adenoma detection rate (risk ratio [RR] 1.30, 95% confidence interval [CI] 1.11-1.53; P=0.001) and right adenoma detection rate (RR 1.43, 95%CI 1.19-1.71; P≤0.001; I2=0%) were noted for the WE group compared to the ACI group. The WI group did not demonstrate a better detection rate of proximal or right adenomas.ConclusionsThe water exchange method for colonoscopy holds promise and should be encouraged in the clinical setting to increase proximal and right adenoma detection rates. This will in turn decrease the incidence of colorectal cancer.

Efficacy of withdrawal time monitoring in adenoma detection with or without the aid of a full-spectrum scope.

Background and study aims Withdrawal time (WT) monitoring and full-spectrum endoscopy (FUSE) have been suggested to increase adenoma detection rate (ADR) due to more accurate evaluation of the hidden areas of the colon. We aimed to evaluate the efficacy of WT monitoring and FUSE on ADR. Patients and methods This was a prospective observational study involving consecutive outpatients, aged 18 to 85 years, undergoing colonoscopy with unselected indications. In phase 1, endoscopists performed 660 colonoscopies either with standard forward-viewing endoscope (SFVE) (n = 330) or with FUSE (n = 330). In this phase, WTs were measured without endoscopist awareness of being monitored. In phase 2, endoscopists were informed of being monitored and performed additional 660 colonoscopies either with SFVE (n = 330) or with FUSE (n = 330). Results WT was lower in phase 1 compared to phase 2 (SFVE: 269 ± 83 vs. 386 ± 60 sec, P < 0.001; FUSE: 289 ± 97 vs. 403 ± 65 sec, P < 0.001). Use of FUSE increased ADR both in phase 1 (33.0 % vs. 27.3 %, P = 0.127) and in phase 2 (41.8 % vs. 33.6 %, P = 0.037). When endoscopists were aware of being monitored, ADR was higher in SFVE (33.6 % vs. 27.3 %; P = 0.090) and FUSE arms (41.8 % vs. 33.0 %; P = 0.024). Improvement in detection of proximal adenomas was associated with WT monitoring [OR 1.577 (95 % C. I. 1.158 – 2.148); P = 0.004], whereas detection of distal adenomas was associated with use of FUSE [OR 1.320 (95 % C. I. 1.022 – 1.705); P = 0.037]. Conclusions Unmonitored endoscopists have suboptimal WT, which increases when they are monitored. WT monitoring and use of FUSE are two reliable and alternative strategies to increase ADR.

Variable Endoscopist performance in proximal and distal adenoma detection during colonoscopy: a retrospective cohort study

BackgroundAdenoma Detection Rate (ADR) is a validated colonoscopy quality indicator. In addition to overall ADR, Distal and Proximal Adenoma Detection Rates may provide important colonoscopy quality information. The goal of this study is to determine the association between distal and proximal adenoma detection (AD) and to identify factors contributing to overall, distal, and proximal AD.MethodsThis is a retrospective cohort study of patients with a noted family history of CRC or positive fecal occult blood test who underwent a screening colonoscopy at a regional colorectal cancer (CRC) screening center between May 2009 and December 2011. Data regarding patient demographics, procedure details, endoscopist characteristics and polyp histology were captured. The main outcomes measured were overall, distal, and proximal AD.Results1907 patients were included. The median age was 60 years and 42% were male. Endoscopist median overall ADR was 25% (30% male, 21% female). Endoscopist distal ADR was only modestly associated with their proximal ADR (Spearman Rank: 0.51 p = 0.11). Highest overall ADR (29 to 45%) was found for endoscopists whose distal and proximal ADRs were above the group median. In multivariate analysis, factors associated with overall, distal, and proximal AD included age, sex, and endoscopist practicing experience.ConclusionInclusion of distal and proximal ADRs, in addition to overall ADR, in colonoscopy quality assessment provides the more accurate feedback on endoscopist performance.

Longer observation time increases adenoma detection in the proximal colon - a prospective study.

Background and study aims Longer observation times are associated with increased adenoma detection rates (ADR) in the entire colon. However, adenomas in the proximal colon are at risk of being missed during colonoscopy. The aim of this study was to investigate the impact of observation time on detection of adenomatous polyps in the proximal colon. Patients and methods This was a prospective study at a university hospital in Germany. Colonoscopies were conducted using magnetic endoscope imaging (MEI) in order to determine the exact position of the scope. Exact observation times spent for the detection of polyps in the proximal and distal colon segments were assessed. The primary outcome was adenoma detection in the proximal colon. ROC curves were generated in order to test the correlation between observation time and adenoma detection. Logistic regression analysis was used to check for interfering factors. Results A total 480 procedures with 538 polyps were available for analysis. The overall adenoma detection rate was 38.5 %. ADR in the proximal colon was 28.0 %. There was a significant association between observation time in the proximal colon and the detection of proximal adenomas ( P < 0.001). The impact of the time factor on ADR was stronger in the proximal compared to the distal colon ( P = 0.030). A net period of 4 min 7 sec was found to be the minimum time span for sufficient adenoma detection in the proximal colon. Conclusion Observation time is significant in terms of adenoma detection in the proximal colon. The impact of observation time on ADR is stronger in the proximal compared to the distal colon. In the proximal colon a minimum time span of 4 minutes should be spent in order to ensure adequate adenoma detection.

Combined Cap-Assisted Total Water With Chromoendoscopy Further Enhance Proximal Adenoma Detection (ADR) and Hyperplastic Polyp Detection: A Retrospective Analysis

Introduction: Missed lesions in proximal colon contribute to interval cancers. Water exchange (WE) combined with chromoendoscopy increased ADR (JIG2012;3:114). Cap-assisted WE further increased ADR (GIE2013;77:944). Combined use of cap-assisted total water colonoscopy, eliminating air, further increased proximal ADR in screening cases. We hypothesize that combined cap-assisted total water with chromoendoscopy on scope withdrawal can further improve proximal ADR in surveillance colonoscopy.Table: Table. Patients demographics, volume of water used, cecal intubation and bowel preparation scoreTable: Table. Adenomas and hyperplastic polyps detection in proximal colonMethods: Retrospective analysis of 3 consecutive series of patients examined with cap-assisted water exchange (CAWE), cap-assisted total water (CATW) and combined cap-assisted total water and chromoendoscopy (CATWC) (with 0.002% indigocarmine/water). CAWE was performed with air turned off and water was infused to facilitate scope insertion while dirty water was suctioned on insertion and withdrawal. Air was used on withdrawal to facilitate examination/removal of lesions. Insertion method was same as CAWE for CATW and CATWC. In CATW, plain water was used and exchanged, with air pockets suctioned to facilitate examination. In CATWC, indigocarmine solution was infused upon withdrawal from cecum and dirty water was exchanged. In both groups, no air was used for entire examination, and polypectomy was done underwater. Small (<5 mm) polyps were removed with biopsy forceps; 5-8 mm polyps, cold snare; and >8 mm polyps, hot snare. Results: 105 patients (35 per group) were included. Patients' demographics were comparable, with no difference in mean interval between index screening and surveillance colonoscopy (4; 4.12; 4.14 years respectively). Total amount of water infused and suctioned were comparable between CATW and CATWC but significantly more than CAWE, and so was the withdrawal time. The overall and proximal ADRs (< 5mm) were higher for CATWC compared with CATW and CAWE (P<0.05). The proximal hyperplastic polyp detection rate was significantly higher for CATWC when compared to CATW and CAWE (40% vs.14.3% vs.14.3% respectively, P<0.05). Conclusion: Limitations: retrospective analysis of consecutive series with small number of patients. Combined cap-assisted total water and chromoendoscopy (CATWC) further improved proximal ADR especially <5mm adenomas. It significantly increased detection of proximal hyperplastic polyps (closely related to sessile serrated polyps) (CGH2013;11:760) in surveillance colonoscopy. These intriguing preliminary data deserves to be confirmed in a prospective RCT.

Efficacy of segmental re-examination of proximal colon for adenoma detection during colonoscopy: a randomized controlled trial.

ClinicalTrials.gov (NCT02581475).

Adenoma and sessile serrated polyp detection rates: variation by patient sex and colonic segment but not specialty of the endoscopist.

Adenoma detection rate is an important quality indicator. High adenoma detection rate is related to fewer interval cancers. Interval cancers arise from sessile serrated polyps, often in the proximal colon. The detection of adenomas and sessile serrated polyps by location may enhance colonoscopy efficacy. The aim of this study was to determine entire colon and segmental adenoma and sessile serrated polyp detection rates and to assess the impact of endoscopist specialty on polyp detection. Colonoscopies performed by 65 multispecialty endoscopists were studied. This study was conducted at an academic medical center. Average-risk outpatients undergoing screening colonoscopy were selected. Polyp detection rates were determined by sex, colon segment, and each endoscopist. Included were 2167 patients. Adenoma and sessile serrated polyp detection rates were 25% and 2% and not significantly different by specialty of the endoscopist. The adenoma detection rate was higher in men (31%) than in women (20%), including each segment in the colon. It was higher proximally (20%) than distally (16%) (p = 0.027) in men, but no different in proximal (11%) and distal colon (11%) (p = 0.66) in women. Sessile serrated polyp detection was the same in men and women at 2% (p = 0.84) and 3-fold higher in the proximal than in the distal colon (1.4% vs 0.5%), but only significantly so in women (p = 0.041). We found a poor correlation between adenoma and sessile serrated polyp detection rates (r = 0.35). This study was limited by its retrospective nature. Prevalent adenomas are detected more often in men than in women, including overall and by colon segment. The proximal adenoma detection rate is significantly higher than the distal adenoma detection rate in men, but segmental rates are similar in women. Sessile serrated polyp detection rates are low, albeit 3-fold higher in the proximal colon, and are found as frequently in men and women. High-quality colonoscopy, as evidenced by adenoma detection rate, varies by endoscopist but is independent of colonoscopist subspecialty.

The feasibility of total water colonoscopy

Traditional colonoscopy is done using minimal air insufflations to distend the colon upon scope insertion until the cecum is reached. Residual stool in the colon is removed with water irrigation and suction. Biopsy and removal of lesions is usually performed on scope withdrawal. Water (exchange) colonoscopy utilizing water infusion in lieu of air insufflations on scope insertion compared favorably to air colonoscopy in screening colonoscopy. Upon reaching the cecum, the residual water is suctioned and air insufflated to distend the colon to facilitate inspection and removal of lesions on scope withdrawal. In randomized controlled trials (RCTs), it has been reported that the water method improves overall success rate of cecal intubation with unsedated colonoscopy, reduces medications requirement in sedated colonoscopy, and increases the proportion of patients completing colonoscopy without sedation medications when given the option of on-demand sedation compared with the conventional air method. Further analysis of RCTs indicated that the water exchange method (with suction removal of dirty water before infusing clean water on scope insertion) is associated with an increase in overall as well as proximal adenoma detection rate (ADR) when compared with the air method. While removal of lesions including biopsies and polypectomy are done normally on scope withdrawal under air insufflations, we examine the possibility of performing total water colonoscopy and polypectomy without using air insufflations.

Impact of a quarterly report card on colonoscopy quality measures

Colonoscopy quality is operator-dependent. Studies assessing the effect of interventions to decrease variation in colonoscopy quality have shown inconsistent results. Since 2009, endoscopists at our university-affiliated, Veterans Affairs medical center have received a quarterly "report card" summarizing individual colonoscopy quality indicators as part of an ongoing quality assurance program. To determine the effect of the quality report card intervention on colonoscopy performance. Retrospective study. Tertiary-care, academic, university-affiliated, Veterans Affairs medical center in Indianapolis, Indiana. Data from 6 endoscopists practicing at the Roudebush Veterans Affairs Medical Center were included. Patients were average-risk, aged 50 years or older, undergoing their first screening colonoscopy. Quarterly report card. The study time frame was July 1, 2008 to December 31, 2008 (before-intervention) and April 1, 2009 to March 31, 2011 (intervention). The primary outcomes were cecal intubation and adenoma detection rates (ADR), adjusted for physician, patient age, and sex. Multivariable logistic regression was performed to determine factors associated with adenoma detection. A total of 928 patients (male 93%, white 78%) were included (before-intervention 336; intervention 592). There were no significant differences in patient age, sex, smoking status, body mass index, bowel preparation quality, colonoscope model, and proportion of colonoscopies performed with a trainee between the before-intervention and intervention phases. In the intervention phase, the adjusted adenoma detection and cecal intubation rates were significantly higher: 53.9% (95% confidence interval [CI], 49.7%-58.1%) vs 44.7% (95% CI, 39.1%-50.4%); P = .013 and 98.1% (95% CI, 96.7%-99.0%) vs 95.6% (95% CI, 92.5%-97.5%); P = .027, respectively. A higher ADR trend in the intervention phase was found for 5 of the 6 physicians. The increment in ADR was due mostly to increased detection of proximal adenomas. There were no significant changes in serrated polyp detection, advanced neoplasm detection, number of adenomas detected per colonoscopy, and mean size of adenomas after implementation of the intervention. The report card intervention remained significantly associated with higher ADRs after adjustment for patient age, sex, and physician (odds ratio 1.45; 95% CI, 1.08-1.94). Single center, small number of endoscopists. A quarterly report card was associated with improved colonoscopy quality indicators. This intervention is practical to generate and implement and may serve as a model for quality improvement programs in different patient and physician groups.

Increase in proximal adenoma detection rate after transition from air to water method for screening colonoscopy in a community-based setting in the United States

Background: The water method of colonoscopy has been shown to increase adenoma detection rate in the United states veteran population, but this has not yet been demonstrated in a non-veteran community setting in the United states. Aims: Our aim is to perform a retrospective study to compare adenoma detection rate between the air and the water colonoscopy methods for screening colonoscopies at a non-veteran community site. Methods: We performed a retrospective review of 100 patients from before and after a single community endoscopist transitioned from air colonoscopy to water colonoscopy. The patients selected were the 50 most recent patients who presented for air colonoscopy and the first 50 patients who underwent water colonoscopy after the transition. patients who presented for indications other than colon cancer screening or surveillance were excluded. The primary end point was overall adenoma detection rate; secondary end points included cecal intubation time, procedure time, polyp detection rate, proximal colon adenoma detection rate, and sedation requirement. Results: There was no significant difference between the two methods in total adenoma detection rate, polyp detection rate, cecal intubation time, total procedure time, or sedation requirement. however, there was a significantly higher proximal adenoma detection rate (34%) with the water method compared to the air method (18%), p=0.015. Conclusion: In a non-veteran community setting, screening colonoscopy done with the water method resulted in a significantly higher proximal colon adenoma detection rate without significantly adding to total procedure time or sedation requirement.

Tu1186 Trainee Participation Increases Adenoma Detection Rates During Screening Colonoscopies Performed With High-Definition Colonoscopes but Not With Standard-Definition Colonoscopes

educational level, and body mass index. Results: Colonoscopy was associated with a statistically significant decreased risk of rectal or left colon cancers (HR=0.58; 95% CI=0.43-0.78 and HR=0.37; 95% CI=0.26-0.52 respectively) but not of right colon cancers (HR=0.85; 95% CI=0.63-1.16). Associations were stronger for several declarations of colonoscopy but did not significantly differ according to stage at diagnosis. Concerning right colon cancers, although associations were not statistically significant, results were stronger for cancers diagnosed at an advanced stage (HR=0.70; 95% CI=0.45-1.10) and for several declarations of colonoscopy (HR=0.71; 95% CI=0.47-1.08). FHCC was associated with an increased risk of adenomas and especially non-advanced adenomas but a non-statistically significant increased risk of colorectal cancer. However, the risk of colorectal cancer was significantly increased in women who had a FHCC but no history of colonoscopy (HR=1.80; 95% CI= 1.36-2.40), but not in women with FHCC and previous colonoscopies (HR=1.10; 95% CI= 0.76-1.61), P for interaction between colonoscopy and FHCC = 0.06. Conclusion: This prospective study confirms the efficiency of colonoscopy regarding distal tumors while adding to the body of evidence for its low efficiency at preventing right colon cancer. While subjects with a FHCC have an approximately 80% excess risk of colorectal cancer, colonoscopy screening reduces their risk to that of subjects with no FHCC. Effort should be made for improving colonoscopy efficiency towards detection of proximal adenomas or early cancers, through adequate colon preparation and careful examination of the cecum.

Tu1185 Should Diabetes Mellitus Be an Indication for Earlier Colorectal Cancer Screening?

educational level, and body mass index. Results: Colonoscopy was associated with a statistically significant decreased risk of rectal or left colon cancers (HR=0.58; 95% CI=0.43-0.78 and HR=0.37; 95% CI=0.26-0.52 respectively) but not of right colon cancers (HR=0.85; 95% CI=0.63-1.16). Associations were stronger for several declarations of colonoscopy but did not significantly differ according to stage at diagnosis. Concerning right colon cancers, although associations were not statistically significant, results were stronger for cancers diagnosed at an advanced stage (HR=0.70; 95% CI=0.45-1.10) and for several declarations of colonoscopy (HR=0.71; 95% CI=0.47-1.08). FHCC was associated with an increased risk of adenomas and especially non-advanced adenomas but a non-statistically significant increased risk of colorectal cancer. However, the risk of colorectal cancer was significantly increased in women who had a FHCC but no history of colonoscopy (HR=1.80; 95% CI= 1.36-2.40), but not in women with FHCC and previous colonoscopies (HR=1.10; 95% CI= 0.76-1.61), P for interaction between colonoscopy and FHCC = 0.06. Conclusion: This prospective study confirms the efficiency of colonoscopy regarding distal tumors while adding to the body of evidence for its low efficiency at preventing right colon cancer. While subjects with a FHCC have an approximately 80% excess risk of colorectal cancer, colonoscopy screening reduces their risk to that of subjects with no FHCC. Effort should be made for improving colonoscopy efficiency towards detection of proximal adenomas or early cancers, through adequate colon preparation and careful examination of the cecum.

795 Combined Dye (Indigocarmine) and Water Method vs. Water Method Alone Further Enhanced Proximal Adenoma Detection Rate (ADR) in Screening Colonoscopy: A RCT

Usual air insufflation during colonoscope insertion has been associated with possible missed cancers and precursor lesions in the proximal colon. Compared to usual air insufflations, chromoendoscopy with dye spray and the water method increase proximal colon adenoma detection rate (ADR) in patients undergoing screening colonoscopy. Dye spray is considered cumbersome. The water method is simple and easy-to-learn, albeit requires practice.

442 Technological Assistance of Cap-Assisted Chromoendoscopy Enhances the Detection Rates of Both Colorectal Adenoma and Proximal Serrated Polyp in an Average-Risk Screening Population: Preliminary Results of a Multi-Center Randomized Controlled Trial

Technological Assistance of Cap-Assisted Chromoendoscopy Enhances the Detection Rates of Both Colorectal Adenoma and Proximal Serrated Polyp in an Average-Risk Screening Population: Preliminary Results of a Multi-Center Randomized Controlled Trial Hyun-Soo Kim*, Hong Jun Park, Chan Sik Won, Hyo Keun Jeon, Dongil Park, Jae Myung Cha, Seun-Ja Park, Hwang Choi, Jeong Eun Shin, Chang Soo Eun, Jin-Oh Kim, Hyun Gun Kim, Seong-Eun Kim, Cheol Hee Park, Tae Il Kim, Sung Noh Hong, Dong-Hoon Yang, Byung Chang Kim, Byungho Nam Yonsei Univ. Wonju College of Medicine, Wonju, Republic of Korea; Sungkyunkwan University College of Medicine, Seoul, Republic of Korea; KyungHee University College of Medicine, Hanam, Republic of Korea; Kosin University College of Medicine, Busan, Republic of Korea; The Catholic University of Korea College of Medicine, Incheon, Republic of Korea; Dankook University College of Medicine, Cheonan, Republic of Korea; Hanyang University College of Medicine, Guri, Republic of Korea; Soonchunhyang University College of Medicine, Seoul, Republic of Korea; Ewha Womans University School of Medicine, Seoul, Republic of Korea; Hallym University College of Medicine, Anyang, Republic of Korea; Yonsei University College of Medicine, Seoul, Republic of Korea; Konkuk University School of Medicine, Seoul, Republic of Korea; University of Ulsan College of Medicine, Seoul, Republic of Korea; National Cancer Center, Goyang, Republic of Korea Background/Aim: There is growing evidence that a transparent cap or chromoendoscopy improve detection of colorectal polyps. However, the combined method of these two technologies has not been proven for colorectal polyp or adenoma detection rate. In this multicenter prospective randomized trial, we examined whether cap-assisted chromoendoscopy (CAP-ACE) enhances colorectal adenoma detection rate especially in the proximal colon. Methods: From March 2010 to October 2011, 1,202 asymptomatic average-risk subjects who underwent the first screening colonoscopy in an age of 45 to 75 were enrolled at 14 hospitals. Eighteen expert colonoscopists (more than 5,000 procedures) have performed procedures. Subjects were randomly allocated to CAP-ACE group and regular colonoscopy (RC) group. We prospectively compared insertion and withdrawal time, polyp detection rate (PDR), adenoma detection rate (ADR), and proximal serrated polyp detection rate (PSPDR) between the two groups. Results: A total of 1,202 subjects were enrolled; 598 CAP-ACEs and 604 RCs were performed. Overall PDR and ADR were 60.3% and 47.6%. A total of 52 advanced lesions were found including 16 tubulovillous adenomas, 2 villous adenomas, 13 high grade dysplasias, 11 intramucosal cancers and 10 invasive cancers. The time to cecal intubation (4.8 vs. 4.8 min, p 0.902) was not different between the groups but withdrawal time was prolonged in CAP-ACE group for indigocarmine solution spray and suction (10.5 vs. 8.7 min, p 0.001). Compared to RC, CAP-ACE did increase PDR (65.9% vs. 54.8%, p 0.001) and ADR (51.8% vs. 45.5%, p 0.033) significantly. In particular, this technological assistance of CAP-ACE even in experts significantly enhanced the proximal adenoma detection rate (34.8% vs. 28.8%, p 0.030) as well as PSPDR (10.5% vs. 6.1%, p 0.006). However, advanced lesions (CAPACE 26/598 (4.3%) vs. RC 26/604 (4.3%), p 0.99) including cancers were equally found between groups. Conclusion: Technological assistance of CAP-ACE enhances not only PDR but also ADR, especially in the proximal colon. These results suggest that CAP-ACE technology provide a potential solution for overcoming the limited effectiveness of colonoscopy in the proximal colon and should be considered as the preferred, high standard colorectal cancer screening method for the average-risk screening population.

Detection of Proximal Adenomas by Colonoscopy Following Flexible Sigmoidoscopy Depends on the Colonoscopy Referral Algorithm: Analysis of the UK Flexible Sigmoidoscopy Study Algorithm Applied to the U.S. National Colonoscopy Study

Detection of Proximal Adenomas by Colonoscopy Following Flexible Sigmoidoscopy Depends on the Colonoscopy Referral Algorithm: Analysis of the UK Flexible Sigmoidoscopy Study Algorithm Applied to the U.S. National Colonoscopy Study