Distal Polyps Research Articles

Risk for Advanced Colorectal Neoplasia in Asymptomatic Adults is Effectively Stratified by Phenotypic Features: Presidential Poster

Purpose: While colorectal cancer (CRC) screening is effective and cost-effective for reducing CRC incidence and mortality, it is underutilized, inefficient, and costly. The ability to stratify risk for advanced neoplasia (AN) could improve screening efficiency and uptake. Several risk factors for AN are not used in practice because of inability to integrate them to produce a risk estimate. Study aim is to create a riskstratifying index for AN (CRC, advanced adenomas, serrated polyps ≥ 1 cm). Methods: We measured socio-demographic and physical features, medical and family history, and lifestyle factors in 50-80 year olds who underwent 1st-time screening colonoscopy between 12/2004 and 9/2011, linking these factors to endoscopic and histologic findings. Using best-subsets logistic regression, we derived a risk equation on a randomly selected 2/3s of the sample. The model selected was based on optimal statistical metrics, including Mallow's C and frequency with which each variable appeared in the top 20 models. Based on model coefficients, we assigned points to each variable to create a risk score (range, -13 to 13). Scores with comparable risk magnitudes were collapsed into risk categories. The model was then tested on the remaining sample. Results: Among 3,025 subjects in the derivation set (mean age 57.3 ± 6.5 years; 52% women), prevalence of AN was 9.4% (including 26 CRCs). Model variables include age, sex, smoking, ethanol use, diet, marital status, NSAID and aspirin use, physical activity, education level, and metabolic syndrome (P-value for fit = 0.09; c-statistic = 0.78). Respective risks of AN in the low- (scores of -13 to -5), intermediate- (scores of -4 to 2) and high- (scores of 3 to 13) were 1.50% (95%, 0.07-2.8%), 6.94%, and 27.3% (P-value for trend < 0.001), with respective cohort proportions of 23%, 59%, and 18%. Ten low-risk subjects had AN (0 CRCs, 6 distal). Based on finding a distal sentinel polyp, sigmoidoscopy would have detected 7 (70%) ANs. Among the 1,475 subjects in the test set (mean age 57.2 ± 6.5 years; 52% women), AN prevalence was 8.4%. Risk of AN in the low-risk subgroup was 2.73% (CI, 1.25-5.11%) and was 5.57% and 25.4% in the intermediate- and high-risk subgroups, respectively (P<0.001), with cohort proportions of 23%, 59%, and 18%. Nine low-risk subjects had AN (0 CRCs, 5 distal, 6 detectable by sigmoidoscopy). Conclusion: This risk index effectively stratifies the risk for AN among asymptomatic adults, identifying a low-risk subgroup of 23% that may be screened effectively and efficiently with tests other than colonoscopy and a high-risk subgroup of 18% for which colonoscopy may be preferred. If validated in other settings, this index could increase the efficiency and uptake of CRC screening.

Mucosal Schwann Cell Hamartoma Masquerading as a Polyp in the Proximal Colon: A Rare Lesion in an Unusual Location

Purpose: Mucosal Schwann cell hamartoma, a rare neural tumor, is rarely found in the colon, yet when seen, it is commonly as a small colorectal polyp, typically on the left side. We report two cases of Schwann cell hamartoma presenting as a polypoid lesion in the proximal colon during routine colonoscopy. Case one: A 78-year-old man with a past medical history of congestive heart failure, hypertension, hyperlipidemia, diabetes mellitus type 2, diverticulosis, and peptic ulcer disease presented with hematochezia. His family history was significant for colorectal cancer in his sister. The patient underwent diagnostic colonoscopy, which revealed scattered diverticula and a 5-mm sessile polyp at the hepatic flexure. Pathology results from the polypectomy specimen revealed colonic mucosa with stromal proliferation of spindle cells with bland nuclear morphology, consistent with Schwann cell hamartoma. Case two: An 84-yearold man with past medical history of hypertension presented for screening colonoscopy. Colonoscopy revealed hemorrhoids and four polyps. Pathology results revealed that a 10-mm sigmoid polyp was a tubular adenoma, a 5-mm hepatic flexure polyp was a tubular adenoma, and a 5-mm splenic flexure polyp was inflammatory. The fourth polyp was a 5-mm polyp in the mid ascending colon. The pathology of this polyp showed colonic mucosa with stromal proliferation of spindle cells with bland nuclear morphology, consistent with Schwann cell hamartoma. Discussion: Neural lesions are relatively rare in the colon, and when found, they present as small colorectal polyps. One type of these polypoid lesions is comprised of a diffuse, uniform proliferation of spindle cells in the lamina propria with a benign cytological appearance and Schwann cell immunophenotype (S100+, CD34-, CD117-, smooth muscle actin- and desmin -). They may occur as multiple lesions associated with inherited syndromes, such as type 1 neurofibromatosis, multiple endocrine neoplasia type 2B, or Cowden syndrome. They may also present as solitary lesions. The term “mucosal Schwann cell hamartomas” has recently been coined in order to distinguish them from other neural lesions, especially those associated with inherited syndromes. These lesions are usually seen in the distal colon, and rarely, they are also observed in the proximal colon as evidenced above, and therefore should be included in the differential of proximal colon polyps. Conclusion: Mucosal Schwann cell hamartoma of the colon is a rare benign lesion, usually presenting as a distal colon polyp, but should also be considered in the differential diagnosis of proximal colon polyps.

Cancer risk and overall survival in mismatch repair proficient hereditary non-polyposis colorectal cancer, Lynch syndrome and sporadic colorectal cancer

Mismatch repair proficient hereditary non-polyposis colorectal cancer (MSS-HNPCC) encloses a heterogeneous group of families consisting of different unknown genetic syndromes and/or aggregations cases. The lack of information about the hereditability of cancer risk in these families makes it difficult to carry out an individualized Genetic Counseling. Therefore, deep description of such families becomes important for a better classification and search for underlying susceptibility causes. The aim of this study is to describe and compare the clinical, morphological features, tumor KRAS status and overall survival in MSS-HNPCC, Lynch and sporadic colorectal cancer. A total of 37 MSS-HNPCC families, 50 Lynch families and 612 sporadic CRC were included. Clinical and morphological data were evaluated by reviewing medical and pathology reports of 55, 69 and 102 tumors respectively. KRAS/BRAF status were detected by allele specific real-time PCR. Standardized incidence ratios (SIR) were calculated among 602 MSS-HNPCC relatives and 668 Lynch relatives. Main features distinguishing MSS-HNPCC were diagnosis age (55.1 ± 12.6), preferential distal location (76%), polyp detection (45%) and familial colorectal cancer incidence (SIR = 6.6). In addition, we found increased incidences rates for kidney, stomach and uterus tumors. KRAS mutation rates were similar in the study populations (48.8 ± 5.8) but higher than those described before by Sanger sequencing. MSS-HNPCC overall survival was similar to Lynch in B Dukes' stage tumors and between Lynch and sporadic in C stage tumors. Anatomical and morphological data of MSS-HNPCC are consistent with other described populations. Our studies disclose an increased HNPCC-extracolonic tumors incidence and improved overall survival in MSS-HNPCC families.

PWE-161 Sessile Serrated Adenomas, Under-Recognised Endoscopically and Under Diagnosed Pathologically

IntroductionThe serrated pathway of colorectal carcinogenesis is a distinct and important pathway leading to CpG island methylated phenotype (CIMP) carcinomas. These lesions are over-represented in interval cancers and may explain...

Bizarre Stromal Cells in the Esophagus

A significant mimicker of malignancy in the esophagus is the presence of atypical/bizarre stromal cells (BSCs). Two patients, a 60-year-old woman and a 59-year-old man, with esophageal polyps at the gastroesophageal junction showed highly atypical/bizarre cells in the polyps' stroma. BSCs were admixed with inflammatory cells and had large atypical nuclei, prominent nucleoli, and variably abundant amphophilic cytoplasm. Immunohistochemical studies showed that BSCs expressed vimentin whereas S-100, CD68, HMB45, CD45, Pan-cytokeratin, CK5/6, p63, CD10, EMA, MART-1, desmin, smooth muscle actin, CD31, CD34, and CMV were negative. Ki-67 showed low proliferative rate (less than 1% positivity). No evidence of intracellular mucin was found after histochemical stains (AB/PAS and mucicarmine). Follow-up endoscopic mucosal resection was available in both cases and showed benign esophageal mucosa and submucosa with disappearance, in one case, or marked decrease of BSCs. Esophageal BSCs reports in the literature invariably locate them in distal esophagus polyps or masses. Awareness of BSCs, of their location and associations, may help to prevent misdiagnosis of malignancy. The literature of esophageal BSCs is reviewed and the approach to this abnormality is discussed.

853 Leaving Distal Colorectal Polyps in Place Can Be Achieved With High Accuracy Using High-Definition Endoscopy With Virtual Chromoendoscopy

The ASGE PIVI statement proposed that a new technology should provide a negative predictive value (NPV) >90% for adenomatous polyp histology to leave distal diminutive colorectal polyps in place without resection. To our knowledge no prior prospective study has yet evaluated the feasibility of virtual chromoendoscopy based, real-time endoscopic prediction of polyp histology for the specific endpoint of leaving distal hyperplastic polyps in place.

Tu1468 Magnifying the Endoscopic Characteristics of Colorectal Lesions With Narrow Band Imaging System

who each evaluated at least 25 colorectal polyps by HD i-scan participated. All small colorectal polyps were examined using HD white-light followed by HD i-scan, then classified into adenomatous or non-adenomatous with a high-or low level of confidence, and subsequently removed and sent for histopathologic examination. Distal colon was defined as rectosigmoid whereas proximal colon was defined as proximal to the rectosigmoid. Sensitivity, specificity, positive, negative predictive value and accuracy with corresponding 95% confidence intervals for prediction of histopathology were calculated. The agreement between surveillance recommendations that would follow optical diagnosis for small colorectal polyps combined with histopathology assessment of the remaining polyps versus histopathology assessment alone was calculated. Results: A total of 309 small colorectal polyps from 93 patients were examined. Of them, 295 (95.5%) were predicted with high-confidence and hence, included in the final analyses. Of these, 110 (37.3%) were located in the distal colon of which 33 (30%) were adenomatous and 77 (70%) non-adenomatous. Diagnostic performances of the endoscopists are depicted in the Table. The negative predictive value for adenoma histology of all small colonic polyps was 87% and increased to 97% for small distal polyps only. In addition, the agreement between surveillance recommendations by formal histopathology versus HD iscan analysis of all small colonic polyps was 81% and increased to 94% for small distal polyps only (Table). Of note, the 6% disagreement reflects patients receiving surveillance earlier than recommended by histopathology alone. Conclusion: Our data indicate that optical diagnosis of small rectosigmoid polyps using HD i-scan is already feasible in the routine practice, with a negative predictive value of 97% and 94% agreement of surveillance recommendations. However, prediction of histology in proximal polyps is only moderate, emphasizing the need for continuous training.

808 Double-Blind, Randomized, Placebo-Controlled, Multicenter Trial of Mesalamine for the Prevention of Recurrence of Diverticulitis

of 0), low (score of 1-3), intermediate (score of 4-6), and high (score of 6-12) risk groups, with respective risks of AN of 1.9% (95% CI, 0.63-4.43%), 4.7%, 9.9% and 25% (trend test, P,0.0001). Very-low and low-risk groups had 1 and 4 CRCs, respectively, all of which were distal. Based on finding a distal sentinel polyp, sigmoidoscopy to the descending colon for subjects in the two lowest risk groups (N=1591; 53% of the sample) would have detected 64 (94%) of 68 ANs. Among 1475 subjects in the validation set (mean age of 57.2± 7.0 years, 52% women), the prevalence of AN was 8.4%; a FHx of CRC was present in 9.2%. Risk of AN in the very low risk group was 1.65% (CI, 0.20-5.84%) and was 3.3%, 10.9%, and 22% in the low-risk, intermediate-risk, and high-risk groups, respectively (P,0.0001). In the two lowest risk subgroups (N=786; 54% of the sample), there were no CRCs, and sigmoidoscopy would have detected 21 (87.5%) of 24 ANs. Conclusion: This new risk index effectively stratifies the risk for AN among asymptomatic adults, identifying low-risk subgroups that may be screened effectively with methods other than colonoscopy. If validated in other settings, use of this index in clinical practice may increase the uptake and efficiency of CRC screening in the U.S.

Accuracy of narrow-band imaging in predicting colonoscopy surveillance intervals and histology of distal diminutive polyps: results from a multicenter, prospective trial

In vivo prediction of colorectal polyp histology by narrow-band imaging (NBI) could potentially avoid post-polypectomy histologic examination or resection of diminutive lesions, thereby reducing costs and risk. To assess whether NBI is able to predict colonoscopy surveillance intervals and histology of distal diminutive polyps according to American Society for Gastrointestinal Endoscopy (ASGE) criteria. Prospective, multicenter study. Five endoscopic centers. Consecutive patients undergoing colonoscopy in 5 centers were included. Participating endoscopists were required to pass a before-study qualifying examination. Histology of polyps that were <10 mm was predicted at NBI and assigned a designation of high or low confidence. Accuracy of high-confidence NBI prediction for polyps ≤5 mm in predicting surveillance intervals and negative predictive value (NPV) for adenomatous histology in the rectosigmoid colon were compared with the ASGE thresholds (90% agreement, 90% NPV). A total of 278 patients (mean age, 63 years; 58% male) were enrolled. At colonoscopy, 574 (97.3%) polyps <10 mm (429 ≤5 mm, 60% adenomatous) were retrieved for histologic analysis. Sensitivity, specificity, positive and negative predictive values, and accuracy of high confidence-NBI predictions for adenomatous histology in lesions ≤5 mm were 90%, 88%, 89%, 89%, and 89%, respectively. High-confidence characterization of polyps ≤5 mm predicted the correct surveillance interval in 92% to 99% of cases, according to the American and European guidelines. NPV of high-confidence NBI for adenomatous histology for the rectosigmoid colon lesions ≤5 mm was 92%. Only experienced endoscopists were included. High-confidence prediction of histology for polyps ≤5 mm appears to be sufficiently accurate to avoid post-polypectomy histologic examination of the resected lesions as well as to allow rectosigmoid hyperplastic polyps to be left in place without resection. ( NCT01675752.).

Use and Misuse of Small Bowel Video Capsule Endoscopy in Clinical Practice

Video capsule endoscopy (VCE) was introduced into the United States in 2000 and has significantly advanced the ability to visualize the small intestinal mucosa by using noninvasive technology. Compared with traditional imaging with small bowel barium imaging, the use of VCE has demonstrated the ability to enhance diagnostic yield in patients with suspected small bowel pathology by approximately 25%‐50% in patients with suspected small bowel disorders. 1‐3 Although the use of VCE has been recommended as the next step in patients with obscure gastrointestinal hemorrhage after a negative upper and/or lower endoscopic examination, 4 its use in other clinical scenarios such as small bowel inflammatory disorders may not be associated with similar diagnostic yields. The major complication associated with the use of VCE remains small bowel retention. Although the risk of this event is virtually nil in patients with obscure bleeding, it can approach 10% in patients with known inflammatory bowel disease (IBD). 5 A critical appraisement of appropriate use of this technology may help physicians and third-party payers to determine which subset of patients with suspected or known small bowel disorders would benefit the most from undergoing a VCE procedure. To critically examine the use of VCE in clinical practice, an evidence-based approach was performed by using the GRADE system, 6,7 and a critical review of the literature on capsule endoscopy was performed by using PubMed, SCOPUS, and the Cochrane Database from 2000‐2012. The quality of evidence could range from high (implying that further research was unlikely to change the authors’ confidence in the estimate of the effect) to moderate (further research would be likely to have an impact on the confidence in the estimate of effect) or low (further research would be expected to have an important impact on the confidence in the estimate of the effect and would be likely to change the estimate). The strength of a recommendation was graded as strong when the desirable effects of an intervention clearly outweigh the undesirable effects and as conditional when there was uncertainty about the tradeoffs. The evidence-based statements generated from this review are shown in Table 1. Studies including more than 20 patients were included for each topic to increase data quality when metaanalyses or randomized controlled trials were not available.

The Incidence and Clinical Characteristics of Proximal Colonic Polyps When the Polyps Are Noted on Rectosigmoid Colon by Colonoscopy

Colorectal cancer is the third most common type of cancer and second leading cause of cancer death overall. Recently, there has been an emphasis on primary screening for colorectal cancer with colonoscopy. In this study, we aimed to address clinical characteristics and incidence of colonic polyps according to location. From January 2009 to December 2010, 6,417 total colonoscopic examinations were performed at Boramae Hospital in Seoul, Korea. We reviewed these patients retrospectively. The distal colon was defined as the rectosigmoid junction. Overall, 1,972 patients (31.3%) had one of more colorectal polyps. Total of 4,445 patients were excluded from this study because of combined advanced colorectal cancer, inflammatory bowel disease, or familial adenomatous polyposis. Patients who had only proximal polyps were 633 (32.1%), 530 patients (26.9%) had both proximal and distal polyps, and 809 patients (41.0%) had polyps only in the rectosigmoid region. The prevalence of the proximal polyps in patients with rectosigmoid polyps was found to be significantly related to the male gender and elderly patients. However, the prevalence of the proximal colonic polyps was not related to the size and number of rectosigmoid polyps. In 530 patients with both rectosigmoid and proximal colonic polyps, the characteristics of proximal colonic polyps as size and number were similar to those of rectosigmoid polyps. Advanced proximal adenomas without distal polyps were found in 25 (29.4%) patients whom were associated with size and pathology. We recommend total colonoscopic examination in all patients regardless of the size and number, especially in elderly males.

The Effect of Polyp Location and Patient Gender on the Presence of Dysplasia in Colonic Polyps

OBJECTIVE:There is increasing evidence of significant clinical and biological differences between proximal and distal colorectal polyps, as well as possible differences based on patient gender. There is a need to optimize and individualize screening strategies. We studied the potential influence of gender and of polyp location on the presence of dysplasia in colon polyps.METHODS:We used a prospective database on adenoma detection to identify patients. The primary outcome was the presence of dysplasia in colonic polyps. Covariates include age, gender, race, lesion size and site, and use of aspirin. Multivariate logistic regression analysis was used to analyze the relationship between the primary outcome and covariates. Results were reported as odds ratios (ORs), 95% confidence intervals (CIs), and P-values.RESULTS:A total of 2,400 patients (50.5% females and 49.5% males) completed colonoscopy for various indications. A total of 3,045 polyps were removed in 1,237 patients. Of those polyps, 54% (n=1,636) were on the right compared with 46% (n=1,409) in the left colon. The proportion of adenomas was significantly greater on the right colon when compared with the left: 69.4% vs. 39.3% (P=<0.0001). Multivariate logistic regression analysis showed that the right colon did have a significant association with dysplasia when controlling for age, gender, polyp size, and use of aspirin (OR=3.1 (95% CI: 2.3–4), P=<0.0001). Female gender was associated with decreased odds of finding dysplasia (OR=0.6 (95% CI: 0.46–0.78), P=0.03).CONCLUSION:Patient characteristics (male gender) as well procedure findings (increase polyp size and right-sided lesions) are associated with increased odds of dysplasia.

Leaving distal colorectal hyperplastic polyps in place can be achieved with high accuracy by using narrow-band imaging: an observational study

Accurate colonoscopic assessment of colorectal polyp histology could avoid resection of distal nonadenomatous polyps and reduce costs and risk. To assess the accuracy of predicting histology by using narrow-band imaging (NBI) in real time for distal colorectal polyps. Prospective observational study. University hospital and ambulatory surgery center. This study involved 225 consecutive adults undergoing elective screening or surveillance colonoscopy. We evaluated real-time histology of 235 distal (rectosigmoid) colorectal polyps from 31 patients by using high-definition colonoscopy and NBI without optical magnification. For each polyp, the endoscopist described size, Paris classification, and surface characteristics (vascular and pit pattern, color, pseudodepression). Before resection, histology was predicted, and a level of confidence (high or low) was assigned. Sensitivity and negative predictive value of high-confidence endoscopic predictions of adenomatous versus hyperplastic histology for polyps ≤ 5 mm. The accuracy of a high-confidence endoscopic prediction was 97.7%, sensitivity for adenomatous histology 93.9%, specificity 98.4%, negative predictive value 97.9%, and positive predictive value 75.6%. The performance characteristics for predicting diminutive distal polyps (≤ 5 mm) with high confidence were sensitivity 96.0%, specificity 99.4%, negative predictive value 99.4%, and positive predictive value 96.0%. Single-center study with a single endoscopist. NBI without optical magnification is sufficiently accurate to allow distal hyperplastic polyps to be left in place without resection and small, distal adenomas to be discarded without pathologic assessment. These findings validate NBI criteria based on color, vessels, and pit characteristics for predicting real-time colorectal polyp histology.

Analysis of colonoscopy examination in 529 healthy adults

Objective To explore the significance of colonoscopy examination in heahhy subjects. Methods A total of 537 health examination cases who underwent colonoscopy from January 2010 to June 2011 in Peking Union Medical College Hospital （PUMCH） health examination center were enrolled, in which 529 cases underwent total colonoscopy. Detection of colorectal lesion, polyp types and pathology were recorded and the correlation between detection rate of polyps, lesion sites and ages as well as gender were analyzed. Results There were 315 male and 214 female, with a mean age of 48.3 ±9. 3 years. A total of 158 colorectal polyps were detected in 104 cases （ 19. 7% ）, including 84 （ 15. 9% ） adenomas, 17 （3.2%） advanced polyps and 1 （0. 2% ） rectal cancer. Other abnormalities were hemorrhoids in 61 cases （11.5%） and inflammation in 22 （4. 2% ）. Colorectal polyps were more frequent in men （P 〈0. 001 ）. Adults older than 50 had higher rates of colorectal polyps （ P 〈 0. 001 ） and advanced polyps （ P 〈 0. 05 ）. The proportion of patients with proximal polyps increased with age, whereas that of patients with distal polyps decreased with age （P 〈 0. 05 ）. Conclusion Colonoscopy is an effective screening modality for colorectal lesions and the importance of colonoscopy on health examination population to prevent colorectal cancer should be stressed. Key words: Colonic polyps ; Colonoscopes ; Mass screening; Health examination

Offering people a choice for colorectal cancer screening

ObjectivesTo assess the population coverage and diagnostic yield of offering an immunochemical faecal occult blood test (FIT) to non-responders to a flexible sigmoidoscopy (FS) invitation.DesignA cohort study conducted in a...

Diverticulosis and colorectal polyps at younger age

An association between diverticulosis and colorectal neoplasms may have implications for colonoscopic prevention of colorectal cancer. We aimed to examine the association between diverticulosis and colorectal polyps with special attention to the age at diagnosis, the anatomical location, and the histological subtype of colorectal polyps. We included all consecutive patients referred for routine colonoscopy between February 2008 and February 2009. We recorded the presence of diverticulosis (defined as at least two diverticula) and colorectal polyps (adenomas and serrated polyps). We included 2310 patients (46.1% men, mean age 58.4 years), of which 37.0% had diverticulosis and 34.2% had one or more colorectal polyps. Multiple logistic regression analysis, including age, sex, and interaction terms with diverticulosis, showed that the association between diverticulosis and colorectal polyps was significantly influenced by age (P=0.009). In patients aged below 60 years, prevalence of colorectal polyps was significantly higher in those with diverticulosis compared with those without diverticulosis: 39.1% (79 of 202 patients) versus 19.6% (176 of 898 patients), adjusted odds ratio (OR) 1.87, 95% confidence interval (CI) 1.26-2.78, and P=0.002. This association was found for both proximal and distal polyps and for all histological subtypes, namely adenomas (adjusted OR 1.60, 95%CI 1.02-2.49, P=0.04), serrated polyps (adjusted OR 1.73, 95% CI 1.03-2.91, and P=0.04), and advanced neoplasms (adjusted OR 2.32, 95%CI 1.31-4.12, P=0.004). Presence of diverticulosis in patients aged below 60 years may be considered a 'red flag' for synchronous adenomas, serrated polyps, and advanced neoplasms. Diverticulosis may represent an indication for earlier initiation of colorectal cancer prevention programs.

Colonoscopy Quality Indicators Differ in the Proximal and Distal Colon

Purpose: Colonoscopy with polypectomy is associated with a reduction in colorectal cancer of the distal colon, but appears to be less protective for lesions of the proximal colon. The adenoma detection rate (ADR) is a validated measure of quality in colonoscopy. Polypectomy detection rate (PDR) has been proposed as a surrogate marker for ADR, demonstrating correlation with ADR in retrospective studies. The aim of this study was to evaluate PDR and ADR separately in the proximal and distal colon. Methods: We reviewed a colonoscopy database for outpatient procedures performed over a 6-month period by 20 gastroenterologists of a single academic medical center. Quality measures including ADR, PDR, mean adenomas per patient (MAP), mean polyps per patient (MPP) and advanced neoplasia detection rate (ANDR) were calculated. Procedures identifying 3 or more adenomas per patient (≥3DR) were also noted. The ratio of adenomas detected to polyps removed (adenoma/polyp ratio) was calculated. ADR and PDR were compared for lesions of the proximal versus distal colon (splenic flexure and below). Data were compared using the Chi-square test. Results: A total of 1921 colonoscopies were performed during the study period. ADR was 31% (13%-42%). ADR was significantly higher in men (36%) compared to women (26%), and in surveillance (47%) compared to screening studies (29%) (p < 0.001). PDR was 49% (16%-64%). PDR was significantly higher in men (63%) than in women (35%) (p < 0.001). The adenoma/polyp ratio was 0.49 (0.29-0.81). MAP was 0.58 (0.27-0.96) and MPP was 1.19 (0.27-1.71). Each measure was lower in the subset of screening colonoscopies (0.50 vs.0.58, p= 0.011 and 1.04 vs. 1.19, p< 0.001). ≥ 3DR was 5.4%, and ANDR was 6.7%. Colorectal cancer was detected in 10 patients (0.52%). In terms of distribution, 1038 polyps (corresponding to 753 adenomas) were removed from the proximal colon, and 1248 polyps (corresponding to 372 adenomas) were removed from the distal colon. Proximal PDR was significantly lower than distal PDR (26% vs. 32%, p= 0.05). Conversely, proximal ADR exceeded distal ADR overall (23% vs. 14%, p< 0.001) and in screening studies (19% vs. 14%; p = 0.016). Conclusion: Quality measures such as ADR and MAP varied amongst endoscopists. Higher ADR did not correlate with endoscopist's volume, patient gender, % surveillance, or withdrawal time. Adenoma/polyp ratio also varied, and PDR was not a consistent correlate of ADR in this study. The majority of adenomas were located in the proximal colon. Proximal polyps were more likely to be adenomas, compared with distal polyps. Proximal PDR may be a better surrogate marker compared with overall PDR for the detection of precancerous lesions of the colon.Table: Proximal and distal ADR and PDRTable: Table. Adenoma vs. polyp detection and other quality measures

A Combination of Snare Polypectomy and APC Therapy for Prolapsing Common Bile Duct Adenoma

Purpose: Bile duct adenomas are an extremely rare entity with only a few reported cases in the literature and limited knowledge about its natural progression. We present a case of common bile duct (CBD) adenoma which was treated endoscopically with snare polypectomy and Argon Plasma Coagulation (APC). An 83 years old man presented with symptoms of cholangitis. Laboratory values were as follow: Total Bilirubin 6.0 mg/dL, Direct Bilirubin 4.6 mg/dL, AST 87, ALT 69 and Alkaline Phosphatase 157 U/L. Endoscopic retrograde cholangiopancreatography (ERCP) was performed and revealed a filling defect in distal CBD immediately proximal to the papilla. Sphincterotomy was done, balloon sweeps were performed, sludge was removed; however, the filling defect persisted for which biliary stent was placed. Six weeks later ERCP was repeated and cholangiogram revealed filling defect in distal CBD measuring 15 mm. Balloon sweep revealed a distal CBD polyp which was prolapsing out of the duct through the papilla and into the duodenum when the balloon was positioned immediately proximal to the papilla. Piecemeal partial removal of the polyp was performed using snare within the CBD and the sample was sent for histopathology which showed tubulovillous adenoma with no signs of dysplasia. Residual filling defect persisted. A stent was placed and good biliary drainage was noted. Surgical consultation was sought for a possible surgical removal of the polyp, however, the patient was considered a poor surgical candidate due to his multiple co-morbidities and it was decided to repeat ERCP with polypectomy. ERCP after 8 weeks showed fixed distal CBD filling defect consistent with residual polyp. Spy glass choledochoscopy was attempted first, however, because of the location of the polyp immediately proximal to the papilla the procedure was suboptimal in visualizing the lesion. Subsequently, choledochoscopy was performed using forward view gastroscope and the residual polyp tissue was identified, removed with snare and ablated with APC under direct visualization. Subsequent cholangiogram showed no filling defect and a biliary stent was placed after APC therapy to maintain drainage. Stent was removed eight weeks later and cholangiogram revealed normal examination of distal CBD with no evidence of residual polyp or any filling defects. At one year follow up the patient was asymptomatic and had normal liver enzymes. This case illustrates that a combination of snare polypectomy and APC is a reasonable palliative therapy for patients who are not surgical candidates due to other co-morbidities. This approach is also cost effective as it not only relieves the biliary obstruction but also obviates the need for multiple ERCPs.

APC and KRAS mutations in distal colorectal polyps are related to smoking habits in men: results of a cross-sectional study

The purpose of this study was (a) to evaluate the association between cigarette smoking and the prevalence of distal colorectal polyps and adenocarcinoma and (b) to analyse genetic alterations representing different molecular pathways of the colorectal carcinogenesis. A total of 623 asymptomatic male (mean age: 53 years; 50-65) car factory workers were included. Information on smoking habits and other lifestyle factors were collected followed by a 60 cm colonoscopy. APC and KRAS mutations and microsatellite status were determined in colorectal lesions (colorectal carcinoma (CRC), hyperplastic (HP) and adenomatous polyps (AP)). Data were analysed using unconditional multiple logistic regression models. Smokers had a higher prevalence of AP (OR 2.1; 95% CI 1.2-3.6; p<0.05) and HP (OR 5.4; 95% CI 2.6- 11.1; p<0.05). No differences in CRC were observed. There was a dose-response relationship with the number of cigarettes smoked. The risk of developing AP or HP decreased after smoking cessation, even among heavy smokers (≥20 packs/year). KRAS mutations were more prevalent among smokers AP (OR 5.6; 95% CI 1.6-20.4; p=0.007). There was a trend of positive association with APC mutations (OR 3.5; 95% CI 0.9-4.4; p=0.096). APC and KRAS mutations were found in 36% and 61% of the HP of smokers, but were absent in non-smokers (p=0.89 and 0.78, respectively). There were no differences in MSI between smokers and non-smokers. Cigarette smoking is associated with a higher risk of developing both HP and AP and a higher prevalence of mutations in APC and KRAS.

Colorectal Polyp Type and the Association With Charred Meat Consumption, Smoking, and Microsomal Epoxide Hydrolase Polymorphisms

We determined the association between charred meat consumption, cigarette smoking, microsomal epoxide hydrolase (mEH) polymorphisms (rs1051740 and rs2234922), and colorectal adenomas and hyperplastic polyps (HPs) and explored gene–environment interactions. Men and women with colorectal adenomas (n = 519), HPs (n = 691), or concurrently with both types of polyps (n = 227) and polyp-free controls (n = 772) receiving a colonoscopy from December 2004 to September 2007 were recruited. Participants completed telephone interviews and provided buccal cell samples; genotyping of mEH was completed using Taqman assays. We conducted polytomous regression and calculated odd ratios (OR) and 95% confidence intervals. Interactions were evaluated using Wald chi-square tests. Consumption of >3 servings of charred meat per week was associated with distal HPs (OR = 2.0, 1.2–3.4) but not adenomas nor either type of proximal polyp. Heavy cigarette smoking (≥ 22 pack-years) was associated with an increased risk for colorectal adenomas (OR = 1.7, 95% CI: 1.2–2.4), HPs (OR = 2.4, 95% CI: 1.7–3.3), and both types (OR = 2.8, 95% CI: 1.8–4.3) with the strongest association for distal polyps. There was no association between mEH genotype and colorectal polyps, nor were any statistically significant gene–environment interactions identified. Future investigation of BaP exposure and colorectal neoplasia should analyze whether associations are dependent upon anatomic location.