Subjects Undergoing Screening Colonoscopy Research Articles

P-251 Prospective validation of the Asian Pacific Colorectal Screening (APCS) score to detect colorectal neoplasia among Mexican subjects undergoing screening colonoscopy

P-251 Prospective validation of the Asian Pacific Colorectal Screening (APCS) score to detect colorectal neoplasia among Mexican subjects undergoing screening colonoscopy

Significance of photodocumentation-associated factors in colonoscopy on the detection rate of colorectal neoplasms.

It is unclear whether photodocumentation is associated with colorectal neoplasm (CRN) detection at colonoscopy, despite its ability to take more images with the development of affordable digital imaging systems. This study aimed to investigate whether photodocumentation-related factors could affect the detection rate of CRNs in healthy subjects. A total of 2,637 subjects undergoing screening colonoscopy in routine health check-ups at CHA Bundang Medical from January to September 2016 were enrolled in this study. Only the endoscopic image data for observation purposes during colonoscopy withdrawal was used in this analysis. The number of observation images, observation time and the speed of photodocumentation (SPD) defined as the number of observation images per minute were used as quantity measures of photodocumentation. The presence of documented anatomical landmarks such as appendix orifice (AO), ileocecal valve (ICV), anorectal junction was used as quality measures of photodocumentation. Among subject-related factors, the independent factors for CRN detection in the multivariate analysis were age, male sex, waist circumference, and family history of colorectal cancer. In photo-documentation-related factors, SPD [Odds ratio (OR) 0.800; 95% confidence interval (CI), 0.740 to 0.864], observation time over 6 min (OR 1.671; 95% CI, 1.145 to 2.439), clear documentation of appendix orifice (AO) (OR 5.976; 95% CI, 4.548 to 7.852) and ileocecal valve (ICV) (OR 3.826; 95% CI, 2.985 to 4.904), and endoscopists (p < 0.001) were independently significant factors. However, the number of observation images was not associated with the detection of CRNs. Lower SPD and clear documentation of cecal landmarks might be associated with an increased detection rate of CRNs.

Sessile serrated lesion detection rates during average risk screening colonoscopy: A systematic review and meta-analysis of the published literature.

Background and study aims Sessile serrated lesion (SSL) detection rate has been variably reported and unlike adenoma detection rate (ADR) is not currently a quality indicator for screening colonoscopy. Composite detection rates of SSL in patients undergoing average risk screening colonoscopy are not available. Methods Electronic database search (Medline, Embase and Cochrane) was conducted for studies reporting detection rates of serrated polyps (SSL, Hyperplastic polyp, traditional serrated adenoma) among average risk subjects undergoing screening colonoscopy. Primary outcomes were pooled SDR (SSL detection rate) and proximal serrated polyp detection rate (PSPDR). Pooled proportion rates were calculated with 95 %CI with assessment of heterogeneity (I 2 ). Publication bias, regression test and 95 %prediction interval were calculated. Results A total of 280,370 screening colonoscopies among average risk subjects that were eligible with 48.9 % males and an average age of 58.7 years (± 3.2). The pooled SDR was available from 16 studies: 2.5 % (1.8 %–3.4 %) with significant heterogeneity (I 2 = 98.66 %) and the 95 % prediction interval ranging from 0.6 % to 9.89 %. When analysis was restricted to large (n > 1000) and prospective studies (n = 4), SDR was 2 % (1.1 %–3.3 %). Pooled PSPDR was 10 % (8.5 %–11.8 %; 12 studies). There was evidence of publication bias ( P < 0.01). Conclusion Definitions of SSL have been varying over years and there exists significant heterogeneity in prevalence reporting of serrated polyps during screening colonoscopy. Prevalence rate of 2 % for SSL and 10 % for proximal serrated polyps could serve as targets while robust high-quality data is awaited to find a future benchmark showing reduction in colorectal cancer arising from serrated pathway.

Polygenic risk score is a predictor of adenomatous polyps at screening colonoscopy

BackgroundSingle nucleotide polymorphism (SNP)-based polygenic risk scoring is predictive of colorectal cancer (CRC) risk. However, few studies have investigated the association of genetic risk score (GRS) with detection of adenomatous polyps at screening colonoscopy.MethodsWe randomly selected 1769 Caucasian subjects who underwent screening colonoscopy from the Genomic Health Initiative (GHI), a biobank of NorthShore University HealthSystem. Outcomes from initial screening colonoscopy were recorded. Twenty-two CRC risk-associated SNPs were obtained from the Affymetrix™ SNP array and used to calculate an odds ratio (OR)-weighted and population-standardized GRS. Subjects with GRS of < 0.5, 0.5–1.5, and > 1.5 were categorized as low, average and elevated risk.ResultsAmong 1,769 subjects, 520 (29%) had 1 or more adenomatous polyps. GRS was significantly higher in subjects with adenomatous polyps than those without; mean (95% confidence interval) was 1.02 (1.00–1.05) and 0.97 (0.95–0.99), respectively, p < 0.001. The association remained significant after adjusting for age, gender, body mass index, and family history, p < 0.001. The detection rate of adenomatous polyps was 10.8%, 29.0% and 39.7% in subjects with low, average and elevated GRS, respectively, p-trend < 0.001. Higher GRS was also associated with early age diagnosis of adenomatous polyps, p < 0.001. In contrast, positive family history was not associated with risk and age of adenomatous polyps.ConclusionsGRS was significantly associated with adenomatous polyps in subjects undergoing screening colonoscopy. This result may help in stratifying average risk patients and facilitating personalized colonoscopy screening strategies.

Linked-color imaging versus white-light colonoscopy in an organized colorectal cancer screening program

Linked-color imaging (LCI), a new image-enhancing technology emphasizing contrast in mucosal color, has been demonstrated to substantially reduce polyp miss rate as compared with standard white-light imaging (WLI) in tandem colonoscopy studies. Whether LCI increases adenoma detection rate (ADR) remains unclear. Consecutive subjects undergoing screening colonoscopy after fecal immunochemical test (FIT) positivity were 1:1 randomized to undergo colonoscopy with LCI or WLI, both in high-definition systems. Insertion and withdrawal phases of each colonoscopy were carried out using the same assigned light. Experienced endoscopists from 7 Italian centers participated in the study. Randomization was stratified by gender, age, and screening round. The primary outcome measure was represented by ADR. Of 704 eligible subjects, 649 were included (48.9% men, mean age ± standard deviation, 60.8 ± 7.3 years) and randomized to LCI (n= 326) or WLI (n= 323) colonoscopy. The ADR was higher in the LCI group (51.8%) than in the WLI group (43.7%) (relative risk, 1.19; 95% confidence interval, 1.01-1.40). The proportions of patients with advanced adenomas and sessile serrated lesions were, respectively, 21.2% and 8.6% in the LCI arm and 18.9% and 5.9% in the WLI arm (not significant for both comparisons). At multivariate analysis, LCI was independently associated with ADR, along with male gender, increasing age, and adequate (Boston Bowel Preparation Scale score≥6) bowel preparation. At per-polyp analysis, the mean ± standard deviation number of adenomas per colonoscopy was comparable in the LCI and WLI arms, whereas the corresponding figures for proximal adenomas was significantly higher in the LCI group (.72 ± 1.2 vs .55 ± 1.07, P= .05) CONCLUSIONS: In FIT-positive patients undergoing screening colonoscopy, the routine use of LCI significantly increased the ADR. (Clinical trial registration number: NCT03690297.).

Clinical characteristics, risk factors and outcomes of asymptomatic rectal neuroendocrine tumors

Rectal neuroendocrine tumors (NET) are often asymptomatic and frequently discovered during health examinations. However, data on the risk factors of asymptomatic rectal NETs are lacking. We investigated the risk factors, clinical characteristics and outcomes of asymptomatic rectal NETs discovered during health screening. Asymptomatic subjects who underwent colonoscopy during routine health screening at a tertiary hospital from March 2009 to July 2014 were reviewed. Subjects with histologically confirmed rectal NETs were compared with healthy controls from the same population. Risk factors for rectal NETs were analyzed by multivariable analysis. Clinical outcomes of the resected NETs were also analyzed. A total of 21,706 Subjects underwent screening colonoscopy during the study period. 3417 were excluded from the study, and 180 rectal NET subjects were compared with 18,109 controls. Multivariable analysis showed that a previous history of malignancy (OR 2.960, 95% CI 1.673-5.237, p<0.001), hypertriglyceridemia (OR 1.482, 95% CI 1.046-2.100, p=0.027), higher fasting plasma glucose levels (OR 1.008, 95% CI 1.003-1.014, p=0.001) and higher carcinoembryonic antigen levels (OR 1.019, 95% CI 1.003-1.035, p=0.021) were significant risk factors while older age (OR 0.964, 95% CI 0.951-0.977, p<0.001) was a preventive factor. One hundred and sixty nine subjects had endoscopic resection, five were treated by local surgery and six by radical surgery. Complete resection was achieved in 152 subjects. There were three cases of positive lymph nodes and one metastasis. Histology revealed four lymphatic, five vascular and two cases of perineural invasion. One hundred and fifty seven subjects were followed up for at least 1year (median 38.6months, 12-84months). There were no recurrences during the follow-up period. Younger age, previous history of malignancy, higher fasting plasma glucose levels and hypertriglyceridemia are significantly associated with rectal NET risk.

Advanced Hepatic Fibrosis in Fatty Liver Disease Linked to Hyperplastic Colonic Polyp.

Aim. Our study aims to determine possible association between biopsy-proven nonalcoholic steatohepatitis (NASH) and hyperplastic polyps (HP) of the colon. Methods. A retrospective cohort observational study. All subjects underwent screening colonoscopy within two years. Data were extracted from the patient charts including demographic, anthropometric measurement, vital signs, underlying diseases, medical therapy, laboratory data, results of the liver biopsy with degree of fibrosis and necroinflammatory activity, the colonoscopy report, and the pathological report of the extracted polyp. Results. A total of 223 patients were included in our study, 123 patients with biopsy-proven NASH and 100 patients without NASH who served as the control group matched for age. 14 colonic adenomas (11% of patients) were found in the NASH group compared with 16 adenomas (16% of patients) found in the control group (P = 0.9). 28 HPs were found in the NASH group (22.7%) compared with only 8 HPs in the control group (8%) (P < 0.05). 21 from the 28 (75%) HPs diagnosed in the NASH group were observed in the high degree fibrosis patients (Fibrosis Stages 3 and 4), 6 HPs (21%) were associated with Fibrosis Stages 1 and 2, and single HP (4%) was associated with Fibrosis Stage 0. Conclusions. Our study showed an association between biopsy-proven steatohepatitis and the burden of hyperplastic polyp. The severity of hepatic fibrosis may play important role in the increased occurrence of HPs.

Endoscopist Fatigue May Contribute to a Decline in the Effectiveness of Screening Colonoscopy.

To assess whether endoscopist fatigue adversely affects the adenoma detection rate (ADR) during screening colonoscopy. Endoscopist fatigue may affect the ADR during colonoscopy; however, this association has not been directly studied. A prospective, multi-center study was performed on screening colonoscopies performed for asymptomatic subjects between March 2012 and December 2012 in Korea. Endoscopist fatigue was defined and measured by Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F) questionnaire. The ADR was compared between fatigued endoscopists and nonfatigued endoscopists, and a multivariate regression analysis was performed to identify independent factors related to the detection of colorectal adenoma. During the study period, a total of 457 subjects underwent screening colonoscopy. After excluding 62 subjects, outcomes of 395 subjects were analyzed. The overall ADR of the study population was 39.7%. The mean score of FACIT-F was 36.4±10.8, and a cutoff score of 25 was chosen to define fatigue. The ADR was lower in fatigued endoscopists than nonfatigued endoscopists (25.0% vs. 42.6%, P=0.008). Using multivariate regression analysis, endoscopist fatigue measured with FACIT-F (odds ratio=3.585; 95% confidence interval, 1.663-7.728; P=0.001) was found to be an independent factor for the ADR. FACIT-F score may be a novel measure for endoscopist fatigue, and ADR was adversely influenced by endoscopist fatigue measured by FACIT-F. Our results suggest that endoscopist fatigue may contribute to a decline in the effectiveness of screening colonoscopy.

432 Split-Dose Bowel Regimen With Low-Volume Polyethylene Glycol and Adenoma Detection Rate: a Randomized, Investigator Blind, Controlled Trial

Split-dose regimen has been demonstrated to be superior to the traditional regimen of administering the preparation the day before colonoscopy in terms of quality of bowel cleansing and patient acceptability. Observational data and secondary or post-hoc analyses of randomized controlled trials suggest that split dose regimens might also significantly improve the adenoma detection. We designed a study primarily aimed at evaluating whether the split-dose regimen is associated with an increase of adenoma detection rate (ADR) in subjects undergoing screening colonoscopy.

Gender- and site-specific differences of colorectal neoplasia relate to vitamin D.

The effect of vitamin D on colorectal adenomas may vary with regard to gender, localisation and histological type of the lesion. To define the role of vitamin D and gender in a Caucasian cohort of subjects undergoing screening colonoscopy after consideration of established risk factors. One thousand five hundred and thirty-two subjects (813 males, 58.8±9.7years; 719 females, 59.7±10.7years) were allocated to tertiles of 25-hydroxyvitamin D3 [25(OH)D3 ] serum concentrations. The number, localisation, size and histology of the detected colonic lesions were recorded. Among men, no association was found between vitamin D and the total number, size and histological stage of adenomas at any site. In female subjects, less women with adenomas were found in the highest vitamin D tertile (N=42/239; 17.2%) as compared to the low vitamin D group (N=60/240; 25.0%; P=0.035). In particular, the number of women with adenomas in the proximal colon was significantly lower in the highest tertile (N=21/239, 8.8%) compared to the low vitamin D group (N=41/240; 17.1%; P=0.007). The rates at other sites were not different. The inverse association of vitamin D serum concentrations with the presence of adenomas in the proximal colon was maintained after adjustment for potential confounders. In 80 women on vitamin D supplementation, the rate of adenomas was lower compared to those not on supplementation (3/80; 3.8%; vs. 90/719; 12.5%; P=0.016). A potential preventive effect of vitamin D on colorectal adenomas was found in the proximal colon in women. This observation is supported by further decrease of lesions in the proximal colon of women on vitamin D supplementation.

Asia-Pacific colorectal screening score and colorectal cancer screening in asymptomatic Asian population.

3545 Background: There has been a rapid rise in colorectal cancer (CRC) incidence in recent decades in many Asian countries. Age, gender, smoking, and family history are the significant risk factors of CRC. This study would like to develop an Asia-Pacific Colorectal Screening (APCS) score to identify subjects with high-risk for colorectal advanced neoplasia (AN) in Asia. Methods: A multicentre study was in 11 Asian cities. A total of 7,463 asymptomatic subjects underwent screening colonoscopy. The first 2,000 subjects were used as a derivation cohort. AN was defined as advanced adenoma and CRC. A multiple logistic regression was applied to the derivation cohort identifying significant risk factors for AN; odds ratios of significant risk factors were then utilized to develop APCS score ranging from 0-6, including age (0=40-49, 1=50-59, 2=60+), gender (0=female, 1=male), family history (0=absent, 1=present), smoking (0=no, 1=current or past), and Body Mass Index (BMI) (0= 23kg/m2). Three tiers...

Mo1063 Cost-Effectiveness Analysis of the First Year of a Colorectal Cancer (CRC) Screening Patient Navigation Program At an Academic Medical Center

G A A b st ra ct s 2005; 100(7):1560-1565). Aim: To compare the efficacy of a previously studied standard preparation of polyethylene glycol (PEG,Colyte®, 4L) to 4 bowel care preparations in SCI subjects: 2L PEG solution with ascorbic acid (MoviPrep® [MP]), MP with neostigmine and glycopyrrolate (MP-NG), Pulsed Irrigation Enhanced Evacuation (PIEE, a colonic cleansing method using a mechanical pump) and PIEE with neostigmine/glycopyrrolate (PIEE-NG). Methods: SCI subjects who previously received 4L of Colyte® as part of a prospective study were compared to SCI subjects who were prospectively randomized to one of the four aforementioned preparations. NG subjects were administered 2 mg neostigmine and 0.4 mg glycopyrrolate intravenously following their preliminary preparation with either MP or PIEE and 1-2 hours before performance of a screening colonoscopy. Individuals with a history of bradyarrhythmia or asthma were excluded from the study. Subjects were observed for changes in vital signs as well as other adverse effects. The quality of bowel preparation was assessed using the Ottawa Scale (OS) by colonoscopists blinded to the study preparations (OS scores range from 0 [best] to 14 [worst]).Results: Twelve SCI subjects completed the previous study with Colyte® and 44 SCI subjects completed the current study (14 MP, 12 PIEE, 13 MP-NG and 5 PIEE-NG). The mean OS results are as follows: Colyte®=4.8 ± 2.5, MP=3.4±1.5, MP-NG=2.5±2.4, PIEE=3.5±3.1, PIEE-NG=3.0±1.05, NG pooled=2.9±2.6. In comparison to the Colyte® group, preparation with MP-NG significant improved OS values (p<0.05); in addition, pooling both NG groups yielded a lower OS value than Colyte® [(2.67±2.4 vs. 4.8±2.5, p<0.05). NG administration was not associated with clinically significant bradycardia or change in oxygen saturation and no subjects required neostigmine reversal. Subjects who had previous experience with Colyte® indicated preference for the current bowel regimens. Conclusions: Compared to Colyte®,MoviPrep® and PIEE enhanced bowel preparation as measured by Ottawa Scores in SCI subjects undergoing screening colonoscopy. In addition, adjunctive NG administration further improved bowel preparation and was not associated with adverse hemodynamic side-effects.

Current management of diminutive colorectal polyps in Taiwan.

The majority of polyps detected during colonoscopy are diminutive polyps, for which the cost of pathological analysis is substantial. In our analysis of a screening cohort of 10737 subjects undergoing screening colonoscopy, a total of 15877 neoplastic lesions were detected, of which 10816 (68.1%) were diminutive lesions. Of those diminutive lesions, 90 (0.83%) had a villous component, 14 (0.1%) had high-grade dysplasia, and none had invasive cancer. Only 1.3% of patients were advised to decrease their surveillance interval because of unfavorable histology. Laws regulating medical practice, uncertainty regarding the accuracy of endoscopic diagnosis of diminutive polyps outside of academic centers, and the relatively low cost of pathological analysis are among the barriers to adopting a 'resect and discard' practice in Taiwan.

PTH-031 Polyp Size, Location and Risk of Advanced Neoplasia in a Bowel Screening Population in North-East Scotland

IntroductionColonoscopic screening for colorectal cancer (CRC) reduces CRC-associated mortality; however, there is some evidence that this effect applies to mainly left-sided, rather than right-sided, CRC. It is postulated that this...

Alcohol Consumption Is a Risk Factor for Colonic Diverticulosis

The exact factors predisposing to colonic diverticulosis other than age are unknown. Cross-sectional study of asymptomatic subjects undergoing screening colonoscopy. A detailed dietary and social questionnaire was completed on all participants. A worldwide review of the literature was performed to further investigate any association between identified risk factors and diverticulosis. Seven hundred forty-six consecutive individuals were enrolled (mean age, 61.1±8.3 y; female: male=0.98). Overall, the prevalence of diverticulosis was 32.8% (95% CI, 29.5-36.2). Diverticula were left-sided, right-sided, or both in 71.5%, 5.8%, and 22.7% of affected subjects, respectively. On univariate analysis, age, sex, adenomatous polyps, advanced neoplasia (adenoma≥1 cm, villous histology, or cancer), aspirin, and alcohol use were significantly associated with diverticulosis. Diet, body mass index, physical activity, and bowel habits were not associated with the disease. On multivariate analysis, increasing age (P<0.001), advanced neoplasia (P=0.021), and alcohol consumption (P<0.001) were significantly associated with diverticulosis. The adjusted odds ratio for diverticulosis in alcohol users was 1.91 (1.36 to 2.69), with increasing prevalence with higher alcohol consumption (P-value for trend=0.001). When the prevalence of diverticulosis reported from 18 countries was analyzed against alcohol use, there was a strong correlation with national per-capita alcohol consumption rates (Pearson correlation coefficient r=0.68; P=0.002). Alcohol use is a significant risk factor for colonic diverticulosis and may offer a partial explanation for the existing East-West paradox in disease prevalence and phenotype. Further studies are needed to investigate this association and its putative pathophysiological mechanisms.

Tu1118 Non-Invasive Determination of Disease Activity in Ulcerative Colitis by Serum Luminex Profiling

Background: In a previous study utilizing multiplex Luminex technology in a cohort of control and ulcerative colitis (UC) patients, we identifiedmultiple proinflammatory cytokines/ chemokines that were increased in the serum and tissue of patients with active UC, determined by histology, compared to control patients. In order to better assess the potential for Luminex profiling for clinical trials, our aim was to investigate the relationship between a validated clinical disease activity tool, the Mayo Disease Activity Index (DAI) and the endoscopy score (ES) subset of the DAI, and the cytokine/chemokine profile in UC patients. Methods: Human serum and colon tissue samples were collected prospectively from 40 control subjects undergoing screening colonoscopy and 137 UC patients. The DAI (a combination of stool frequency, blood in the stool, physician global assessment, and ES) was assessed for UC patients at the time of colonoscopy. Serum and tissue cytokines/chemokines were measured by a 39-plex MILLIPLEX bead assay. We classified UC patients by DAI or ES alone into inactive (DAI 0-2; ES 0) and active (DAI 3-12; ES 1-3) disease. Cytokine/chemokine levels were analyzed based upon the DAI and ES classifications and were compared to control patients. We also assessed the correlation of DAI with the serum and tissue cytokine/ chemokine levels. Results: When active versus inactive UC was defined by a DAI cutoff of 3 or greater, patients with active UC had increased serum levels of eotaxin-1, G-CSF, GMCSF, IL-8, and TGF-α compared to control patients (all with at least p,0.05). None of the tissue or serum cytokine/chemokine levels resulted in a correlation greater than an r2 value of 0.18 with DAI as a continuous variable. When active disease was defined by an ES of 1 or greater, serum eotaxin-1, G-CSF, GM-CSF, IL-8, and IL-9 levels were increased in active UC (all p,0.05). Eotaxin-1, GM-CSF, and IL-8 were also increased in tissues when compared to controls when active UC was defined by either increased DAI or ES. In total, there were 21 of 39 cytokines/chemokines increased in tissues from patients with a DAI of 3 or greater vs. normal control subjects, and 20 were increased when ES was used. In active vs. inactive UC by DAI or ES, there were increases in serum levels of G-CSF, IFNγ, and IL-8; IL-15 and TGF-α were also increased when active UC was defined by DAI. In active vs. inactive UC defined by DAI, there were 17 analytes increased in tissues. When defined by ES, there were 22 analytes increased, including eotaxin-1, G-CSF, and IL-8. Conclusions: Luminex profiling was robust in identifying active disease defined by using either the DAI or the ES. Testing for serum cytokines/chemokines, especially G-CSF, IL-8, and eotaxin-1, may represent a non-invasive strategy for detecting active UC that compares favorably with current clinical tools.

Bisacodyl plus split 2-L polyethylene glycol-citrate-simethicone improves quality of bowel preparation before screening colonoscopy

To compare the bowel cleansing efficacy, tolerability and acceptability of split 2-L polyethylene glycol (PEG)-citrate-simethicone (PEG-CS) plus bisacodyl (BIS) vs 4-L PEG for fecal occult blood test-positive screening colonoscopy. This was a randomised, observer-blind comparative study. Two hundred and sixty-four subjects underwent screening colonoscopy (mean age 62.5 ± 7.4 years, male 61.7%). The primary objective of the study was to compare the bowel cleansing efficacy of the two preparations. BIS plus PEG-CS: 3 tablets of 5-mg BIS at 16:00, PEG-CS 1-L at 19:00 and 1-L at 7:00, 4-L PEG: 3-L at 17:00, and 1-L at 7:00. Colonoscopy was carried out after 11:00, at least 3 h after the completion of bowel preparation. Bowel cleansing was evaluated using the Harefield Cleansing Scale. Bowel preparation was successful for 92.8% of subjects in the PEG-CS group and for 92.1% of subjects in the 4-L PEG (RR = 1.01; 95%CI: 0.94-1.08). BIS + PEG-CS was better tolerated than 4-L PEG. A greater rate of patients in the BIS + PEG-CS group had no difficulty and/or were willing to repeat the same preparation compared to split-dose 4-L PEG group. Subjects in the BIS + PEG-CS group rated the prep as good or satisfactory in 90.6% as compared to 77% in the 4-L PEG (P = 0.003). Subjects receiving BIS + PEG-CS stated they fully adhered to instructions drinking all the 2-L solution in 97.1% compared with 87.3% in the 4-L PEG (P = 0.003). BIS plus split 2-L PEG-CS was as effective as but better tolerated and accepted than split 4-L PEG for screening colonoscopy. This new procedure may increase the positive attitude and participation to colorectal cancer screening colonoscopy.

First-Degree Relatives of Colorectal Cancer Patients Are Likely to Show Advanced Colorectal Neoplasia despite a Negative Fecal Immunochemical Test

Background/Aims: Fecal immunochemical test (FIT) is an integral component of most colorectal cancer (CRC) screening programs. However, little is known about clinical risk factors associated with advanced colorectal neoplasia (CRN) despite negative FIT results. The aim of this study was to determine the clinical predictors of advanced CRN despite negative FIT results. Methods: We performed FITs for asymptomatic subjects ≥50 years from January 2009 to December 2010. Patients who underwent colonoscopy for a medical check-up, despite a negative FIT result, were included to evaluate the clinical predictors of advanced CRN based on colonoscopy. Results: During the study period, 373 subjects underwent screening colonoscopy despite their negative FIT results. Among those 373 subjects, 356 (95.4%) did not show any advanced CRNs; however, 17 (4.6%) subjects showed advanced CRNs on their colonoscopies despite negative FIT results. Being a first-degree relative of a CRC patient was significantly associated with advanced CRNs in univariate analysis (p = 0.031). According to multivariate logistic regression analysis, being a first-degree relative of a CRC patient was a significant predictor of advanced CRNs despite negative FIT results (OR 7.33; 95% CI, 0.53–35.08; p = 0.013). Conclusion: First-degree relatives of CRC patients are likely to show advanced CRNs despite a negative FIT.

Tu1325 Association Between Common Functional Genetic Polymorphisms and CpG Island Methylation Status in Colonic Mucosa in Ulcerative Colitis

Introduction/Aims: Lubiprostone enhances intestinal fluid secretion by activation of ClC-2, and likely CFTR chloride channels, and is used clinically to treat constipation. It has also been shown to stimulate recovery of mucosal barrier function in ischemic porcine intestine and modify tight junction (TJ) proteins. A defect in barrier function is thought to contribute to both the pathogenesis of inflammatory bowel disease (IBD) and to disease relapse. The aim of this study was to investigate if lubiprostone improves barrier function in colonic biopsies from IBD patients. Methods: Mucosal biopsies were obtained from the sigmoid colon of normal subjects undergoing screening colonoscopy, Crohn's disease (CD) and ulcerative colitis (UC) patients in remission with approval of UCSD IRB. Biopsies were mounted in Ussing chambers, and bathed in Ringer's solution at 37oC. After stabilization for 30 minutes, the tissues were treated with lubiprostone (0.01, 0.1 or 1.0 μM), or vehicle. Paracellular permeability to macromolecules was assessed with the fluorescent marker, FITCdextran (4 kD). Transepithelial electrical resistance (TER) was monitored over 120 minutes. Ion transport responses, measured as short-circuit current (Isc), were recorded for lubiprostone, the cAMP agonist forskolin, and the calcium agonist carbachol (CCh). Statistical analysis was performed using ANOVA or Student's t-test. Results: Lubiprostone increased Isc across human colon in a concentration-dependent manner in all tissues (p<0.05; n=1517). Peak responses to lubiprostone were significantly lower in CD and UC vs. controls (p<0.05; n=15-17). The Isc response to forskolin was similar in controls, CD and UC tissues, while lubiprostone reduced the Isc response to forskolin in a dose-dependent manner. The Isc response to CChwas similar in all three subject groups and was unaffected by lubiprostone pre-treatment. Lubiprostone (1.0 μM) increased the diminished TER in CD biopsies vs. untreated by 8 ± 3 % (n=17, p<0.05) but had no significant effect on UC or normal biopsies. FITC-dextran permeability was not increased in CD or UC vs. controls and was unaffected by lubiprostone. Conclusion: Lubiprostone restored TER in CD biopsies indicating a possible role for lubiprostone as an enhancer of barrier function in CD vs. UC. Moreover, the Isc response to lubiprostone was lower in biopsies from IBD patients vs. normal controls whereas responses to forskolin or CCh were unchanged by disease status. This suggests that lubiprostone could be used to improve barrier function in CD without a risk of excessive fluid secretion. Support provided by Takeda Pharmaceuticals North America, Inc. & NIH DK080506.

Sensitivity of immunochemical faecal occult blood testing for detecting left- vs right-sided colorectal neoplasia

Background:Faecal occult blood tests (FOBTs) are used for colorectal cancer (CRC) screening. We aimed to assess the sensitivity of an immunochemical FOBT for detecting advanced colorectal neoplasia in the left vs the right colon and to explore reasons for potential differences in site-specific test performance.Methods:We prospectively measured faecal occult blood levels by a quantitative immunochemical FOBT (RIDASCREEN) in 2310 average-risk subjects undergoing screening colonoscopy. We compared diagnostic performance for subjects with left- vs right-sided advanced neoplasia, as well as patient characteristics and adenoma characteristics that have been suggested to impact faecal haemoglobin levels.Results:Sensitivities for subjects with left- vs right-sided advanced neoplasia were 33% (95% confidence interval (CI), 26–41%) and 20% (CI, 11–31%) (P=0.04) at a specificity of 95% (overall sensitivity: 29%) and the areas under the receiver-operating characteristics curve were 0.71 (CI, 0.69–0.72) and 0.60 (CI, 0.58–0.63), respectively. Pedunculated shape was strikingly more common in participants with left- vs right-sided advanced neoplasia (47% vs 14%). In logistic regression analyses adjusted for site, pedunculated shape was statistically significantly associated with test sensitivity (P=0.04).Conclusions:The immunochemical FOBT in our study was more sensitive for detecting subjects with left- vs right-sided advanced colorectal neoplasia. Our findings may stimulate further diagnostic research in the field as well as modelling analyses to estimate the potential effect of site-specific test performance on the effectiveness of annual or biennial FOBT-based screening programmes, in particular with respect to protection from right-sided CRC.