Colonoscopy with endoscopic resection of detected colonic adenomas interrupts the adenoma-carcinoma sequence and reduces the incidence of colorectal cancer and cancer-related mortality. In the past decade, there have been significant developments in instruments and techniques for endoscopic polypectomy. Guidelines have been formulated by various professional bodies in Europe, Japan and the United States, but some of the recommendations differ between the various bodies. An expert professional workgroup under the auspices of the Academy of Medicine, Singapore, was set up to provide guidance on the endoscopic management of colonic polyps in Singapore. A total of 23 recommendations addressed the following issues: accurate description and diagnostic evaluation of detected polyps; techniques to reduce the risk of post-polypectomy bleeding and delayed perforation; the role of specific endoscopic resection techniques; the histopathological criteria for defining endoscopic cure; and the role of surveillance colonoscopy following curative resection.
Adenoma/surgery* ; Colonic Neoplasms/surgery* ; Colonic Polyps/surgery* ; Colonoscopy/methods* ; Colorectal Neoplasms/pathology* ; Humans ; Singapore ; United States

Objective: Serrated adenoma is recognized as a precancerous lesion of colorectal cancer, and the serrated pathway is considered as an important pathway that can independently develop into colorectal cancer. However, little is known about the related risk factors of carcinogenesis of serrated adenoma. The purpose of this study was to analyze the distribution characteristics and potential malignant factors of serrated adenoma in the colon and rectum. Methods: A retrospective case-control study was conducted to collect the clinical data of patients with serrated adenoma who underwent colonoscopy and were pathologically diagnosed in the Cancer Hospital of Chinese Academy of Medical Sciences from April 2017 to July 2019, and exclude patients with two or more pathological types of lesions. The clinical characteristics of serrated adenoma were summarized, and univariate and logistic multivariate regression analysis was conducted to explore the influencing factors for serrated adenoma to develop malignant transformation. Results: Among 28 730 patients undergoing colonoscopy, 311 (1.08%) were found with 372 serrated adenomas, among which 22 (5.9%) were sessile serrated adenomas/polyps, 84 (22.6%) were traditional serrated adenomas, and 266 (71.5%) were unclassified serrated adenomas according to WHO classification. The pathological results showed that 106 (28.5%) lesions were non-dysplasia, 228 (61.3%) lesions were low grade intraepithelial neoplasia, and 38 (10.2%) lesions were high grade intraepithelial neoplasia or cancer. There were 204 (54.8%) lesions with long-axis diameter <10 mm and 168 (45.2%) lesions with length long-axis ≥ 10 mm. 238 (64.0%) lesions were found in the left side colon and rectum and 134 (36.0%) lesions in the right side colon. Gross classification under endoscopy: 16 flat type lesions (4.3%), 174 sessile lesions (46.8%), 117 semi-pedunculated lesions (31.5%), 59 pedunculated lesions (15.9%). Narrow-band imaging international colorectal endoscopic (NICE) classification: 85 (22.8%) type I lesions, 280 (75.3%) type II lesions, 4 (1.1%) type III lesions. Univariate analysis showed that lesion size, lesion location, lesion site and different WHO classifications were associated with malignant transformation of colorectal serrated adenoma (all P<0.05). For the serrated adenomas with different NICE classifications, there were statistically significant differences in the distribution of malignant lesions among groups (P=0.001). Multivariate analysis showed that the long-axis diameter of the lesion ≥10 mm (OR=6.699, 95% CI: 2.843-15.786) and the lesion locating in the left side colorectum (OR=2.657, 95% CI: 1.042-6.775) were independent risk factors for malignant transformation. Conclusions: Serrated adenomas mainly locate in the left side colon and rectum, and are prone to malignant transformation when the lesions are ≥10 mm in long-axis diameter or left-sided.
Adenoma/pathology* ; Adenomatous Polyps/pathology* ; Carcinogenesis ; Case-Control Studies ; Colonic Polyps/pathology* ; Colonoscopy ; Colorectal Neoplasms/pathology* ; Disease Progression ; Humans ; Precancerous Conditions/pathology* ; Retrospective Studies ; Risk Factors

PURPOSE: This study aimed to validate an automated calculating system developed for determining the adenoma detection rate (ADR). METHODS: To calculate the automated ADR, the data linking processes were as follows: (1) matching the selected colonoscopy results with the pathological results, (2) matching the polyp number from colonoscopy with that from pathology and confirming the histopathological results of each colonic polyp, and (3) confirming the histopathological results, especially the adenoma status of each colonic polyp. To verify the accuracy of the automated ADR calculating system, we manually calculated the ADR for 3 months through medical record review. Accuracy was calculated by measuring the error rate for each value. The cause of error was analyzed by additional order and chart review. RESULTS: After excluding 318 cases, 2,543 patients (1,351 men and 1,192 women; median age, 57.9 years) who underwent colonoscopy were included in this study. When the automated calculating system was used, polyps were found in 1,336 cases (52.6%) and adenomas were found in 1,003 cases (39.4%). When the manual calculating system was used, polyps were found in 1,327 cases (52.2%) and adenomas were found in 1,003 cases (39.4%). The accuracies of the polyp detection rate and ADR according to the automated calculating system were 99.3% and 100%, respectively. CONCLUSION: We developed a system to automatically calculate the ADR by extracting hospital electronic medical record results and verified that it provided satisfactory results. It may help to improve colonoscopy quality.
Adenoma ; Colon ; Colonic Polyps ; Colonoscopy ; Colorectal Neoplasms ; Electronic Health Records ; Female ; Humans ; Male ; Medical Records ; Pathology ; Polyps ; Quality Improvement

BACKGROUND/AIMS: Colorectal polyps are a common cause of lower gastrointestinal bleeding in children. Our aim was to study the causes of isolated lower gastrointestinal bleeding and to analyze the characteristics of the colorectal polyps found in our cohort. METHODS: We retrospectively reviewed colonoscopic procedures performed between 2007 and 2015. Children with isolated lower gastrointestinal bleeding were included in the study. RESULTS: A total of 185 colonoscopies were performed for isolated lower gastrointestinal bleeding. The median patient age was 8 years, and 77 patients (41.6%) were found to have colonic polyps. Normal colonoscopy findings were observed and acute colitis was detected in 77 (41.6%) and 14 (7.4%) patients, respectively. Single colonic polyps and 2–3 polyps were detected in 73 (94.8%) and 4 (5.2%) patients with polyps, respectively. Of the single polyps, 69 (94.5%) were juvenile polyps, among which 65 (94.2%) were located in the left colon. CONCLUSIONS: Single left-sided juvenile polyps were the most common cause of isolated lower gastrointestinal bleeding in our study. It was rare to find multiple polyps and polyps proximal to the splenic flexure in our cohort. A full colonoscopy is still recommended in all patients in order to properly diagnose the small but significant group of patients with pathologies found proximal to the splenic flexure.
Child ; Cohort Studies ; Colitis ; Colon ; Colon, Transverse ; Colonic Polyps ; Colonoscopy ; Hemorrhage ; Humans ; Pathology ; Polyps ; Retrospective Studies

BACKGROUND: It has been reported that the expression of the inhibitor of apoptosis protein (IAP) family increases in patients with colon cancer. We evaluated the expression of the IAP family and human telomerase reverse transcriptase (hTERT) in normal colon mucosa from patients with advanced colorectal adenoma and investigated their features according to characteristics of advanced colorectal adenoma. METHODS: While resections of polyps were performed in patients (n = 80) diagnosed with advanced colorectal adenoma or carcinoma in situ, additional normal tissues were obtained from the sigmoid colon. In healthy patients (n = 16), blind biopsies were performed on the sigmoid colon. The expression of the IAP family, including survivin, XIAP, cIAP1, and cIAP2, and hTERT, were analyzed by real-time PCR in both groups. RESULTS: A total of 80 advanced colorectal adenoma patients (71.3% male, mean age of 60.4 years) and 16 control patients were enrolled in this study. The mean ranking of cIAP2 was higher in the control group (68.88 vs. 44.43, P = 0.001). The expression levels of hTERT, survivin, XIAP, and cIAP from both groups showed no differences. The expression of survivin, XIAP, cIAP1, cIAP2, and hTERT depending on certain factors of advanced adenoma, including the number (two or fewer vs. three or more), size (smaller than 1 cm vs. larger than 1 cm), grade of dysplasia (low grade adenoma vs. high grade adenoma), pathology (tubular adenoma vs. villous adenoma), and presence of endometrial intraepithelial neoplasms, showed no significant correlations in the Mann-Whitney U-test. CONCLUSIONS: The expression of the IAP family and hTERT, except cIAP2, in the normal mucosa of patients with advanced colorectal adenoma were not different from those of the control group. There were no differences in the IAP family and hTERT according to the characteristics of advanced adenoma.
Adenoma* ; Biopsy ; Carcinoma in Situ ; Colon ; Colon, Sigmoid ; Colonic Neoplasms ; Humans ; Humans* ; Inhibitor of Apoptosis Proteins* ; Male ; Mucous Membrane ; Pathology ; Polyps ; Real-Time Polymerase Chain Reaction ; Telomerase*

PURPOSE: Although there is a consensus about the need for surveillance colonoscopy after endoscopic resection, the interval remains controversial for large sessile colorectal polyps. The aim of this study was to evaluate the long-term outcome and the adequate surveillance colonoscopy interval required for sessile and flat colorectal polyps larger than 20 mm. MATERIALS AND METHODS: A total of 204 patients with large sessile and flat polyps who received endoscopic treatment from May 2005 to November 2011 in a tertiary referral center were included. RESULTS: The mean age was 65.1 years and 62.7% of the patients were male. The mean follow-up duration was 44.2 months and the median tumor size was 25 mm. One hundred and ten patients (53.9%) received a short interval surveillance colonoscopy (median interval of 6.3 months with range of 1-11 months) and 94 patients (46.1%) received a long interval surveillance colonoscopy (median interval of 13.6 months with range of 12-66 months). There were 14 patients (6.9%) who had local recurrence at the surveillance colonoscopy. Using multivariate regression analysis, a polyp size greater than 40 mm was shown to be independent risk factor for local recurrence. However, piecemeal resection and surveillance colonoscopy interval did not significantly influence local recurrence. CONCLUSION: Endoscopic treatment of large sessile colorectal polyps shows a favorable long-term outcome. Further prospective study is mandatory to define an adequate interval of surveillance colonoscopy.
Adult ; Aged ; Colonic Neoplasms/*diagnosis/pathology/surgery ; Colonic Polyps/*diagnosis/pathology/surgery ; *Colonoscopy ; Endoscopic Mucosal Resection ; Female ; Humans ; Male ; Middle Aged ; Neoplasm Recurrence, Local/*diagnosis ; Prospective Studies ; Time Factors ; Watchful Waiting/*methods

Serrated polyposis syndrome (SPS) is closely associated with the initiation and development of colorectal cancer (CRC), however, there is few research on SPS in China. Serrated polyps can be divided into hyperplastic polyps, sessile serrated polyps and traditional serrated polyps. The diagnosis standard of SPS is as following: (1) There are at least 5 serrated lesions in proximal colon, and diameter of more than 2 lesions is >10 mm; (2) The patient has one serrated polyp with family history of SPS; (3) More than 20 serrated polyps can be found in the entire large bowel. The risk of SPS is relatively high in the development of colorectal cancer and 25%-70% of the SPS patients is diagnosed with synchronous or metachronous colorectal cancer during following-up. The clinical characteristics of SPS include that patients are relatively old; no significant racial difference exists in the morbidity; patients have family history of colorectal cancer. The mutation of BRAF or KRAS gene, which induces colorectal cancer through the RAS-RAF-MAPK signaling pathway, is often found in SPS as well as CpG island methylation phenotype (CIMP) and microsatellite instability (MSI). The difference between SPS and traditional familial adenomatous polyposis (FAP) should be noted because of the different pathology mechanism, clinical characteristics and the risk of malignancy. Nowadays, the common technologies of detecting serrated polyps are auto-fluorescence imaging (AFI) and narrow-band imaging (NBI), whose detective rate is around 55%. The SPS patients are advised to undergo the resection of all the serrated polyps with diameter larger than 3-5 mm and receive the colonoscopy examination every 1 or 2 year. Not only the research about SPS is on the initiation step and the molecular mechanism is still unknown, but also the scholars do not come to achieve agreement about the risk of SPS in the malignancy of colorectal cancer, which is essential for further research therefore.
Adenoma ; genetics ; pathology ; therapy ; Adenomatous Polyposis Coli ; genetics ; pathology ; therapy ; Colonic Polyps ; Colonoscopy ; Colorectal Neoplasms ; genetics ; pathology ; therapy ; DNA Methylation ; Genes, ras ; Humans ; Microsatellite Instability ; Mutation ; Phenotype ; Proto-Oncogene Proteins B-raf ; Syndrome

OBJECTIVE: To determine the effect of reduced abdominal compression in prone position on ascending colonic movement during supine-to-prone positional change during CT colonography (CTC). MATERIALS AND METHODS: Eighteen consecutive patients who had undergone prone CTC scanning with cushion blocks placed under the chest and hip/thigh to reduce abdominal compression and had confirmed sessile polyps > or = 6 mm in the well-distended, straight, mid-ascending colon, were included. Radial location along the ascending colonic luminal circumference (degrees) was measured for 24 polyps and 54 colonic teniae on supine and prone CTC images. The supine-to-prone change ranging between -180degrees and +180degrees (- and + for internal and external colonic rotations, respectively), was determined. In addition, possible causes of any ascending colonic rotations were explored. RESULTS: Abdominal compression during prone CTC scanning completely disappeared with the use of cushion blocks in 17 of 18 patients. However, some degrees of ascending colonic rotation were still observed, with the radial location changes of -22degrees to 61degrees (median, 13.9degrees) for the polyps and similar degrees for teniae. Fifty-four percent and 56% of polyps and teniae, respectively, showed changes > 10degrees. The radial location change of the polyps was significantly associated with the degree of anterior shift of the small bowel and mesentery (r = 0.722, p < 0.001) and the degree of posterior displacement of the ascending colon (r = 0.566, p = 0.004) during supine-to-prone positional change. CONCLUSION: Ascending colonic rotation upon supine-to-prone positional change during CTC, mostly in the form of external rotation, is not eliminated by removing abdominal compression in prone position.
Aged ; Colon/*pathology/*radiography ; Colonic Polyps/*radiography ; Colonography, Computed Tomographic/*methods ; Female ; Humans ; Male ; Middle Aged ; Movement ; Prone Position/*physiology ; Retrospective Studies ; Rotation

BACKGROUND/AIMS: There have been several studies showing that retroflexion (RF) in the right colon (RC) could reduce the polyp miss rate of proximal colon during colonoscopy. This study was conducted to evaluate the additional benefit of RF technique in the RC. METHODS: Patients who underwent colonoscopy from May 2008 to April 2011 were enrolled in the study. Data were obtained by retrospectively reviewing the medical records. RF was attempted in every patients undergoing colonoscopy since May 2008 except in cases of small RC vault, co-morbidity, severe diverticulosis, failed RF despite two trials, complaints of severe abdominal pain, or time burden. At first, RC was examined under direct vision. It was then examined by RF to detect missed polyps during the initial observation. Finally, the RC was re-examined with direct view. RESULTS: The cumulative RF success rate in the RC was 78.84% (1,805 of 2,319). The RF success rate increased with the number of cases (50% at 160 cases, 70% at 400 cases, and reached near 90% over 1,000 cases). Few polyps (4.88%) were detected only with RF and the additional adenoma detection rate was 3.32%. The additional polyp/adenoma detection rates were higher in the old age group (p<0.01). There were no RF associated perforation or severe complication. CONCLUSIONS: Using RF examination, additional 4.88% of polyps could be detected in the RC. This technique could be a useful and safe method to detect hidden polyp during colonoscopy.
Adenoma/diagnosis/pathology ; Adult ; Aged ; Colon, Descending/pathology ; Colonic Neoplasms/diagnosis/pathology ; Colonic Polyps/*diagnosis ; *Colonoscopy ; Female ; Humans ; Male ; Middle Aged ; Retrospective Studies

PURPOSE: Colonoscopic polypectomy and surveillance are important to prevent colorectal cancer and identify additional relative risk factors for adequate surveillance. In this study, we evaluated risk factors related to recurrent high-risk polyps during the surveillance of patients with high-risk polyps. MATERIALS AND METHODS: We included 434 patients who had high-risk polyps (adenoma > or =10 mm, > or =3 adenomas, villous histology, or high-grade dysplasia) on the baseline colonoscopy and underwent at least one surveillance colonoscopy from 2005 to 2011 at Severance Hospital. Data regarding patient characteristics, bowel preparation and polyp size, location, number, and pathological diagnosis were retrospectively collected from medical records. Patients with recurrent high-risk polyps were compared with patients with low-risk or no polyps during surveillance. RESULTS: Patients were predominantly male (77.4%), with a mean age of 61.0+/-8.6 years and mean follow-up of 1.5+/-0.8 years. High-risk polyps recurred during surveillance colonoscopy in 51 (11.8%) patients. Results of multivariate analysis showed that male gender, poor bowel preparation, and a larger number of adenomas were independent risk factors for recurrent high-risk polyps (p=0.047, 0.01, and <0.001, respectively). Compared with high-risk polyps found during initial colonoscopy, high-risk polyps on surveillance colonoscopy had higher proportions of small adenomas, low-risk pathology, and fewer adenomas overall, but there was no difference in location. CONCLUSION: Male patients and those with poor bowel preparation for colonoscopy or higher numbers of adenomas were more likely to experience recurrent high-risk polyps.
Adenomatous Polyps/pathology/*surgery ; Aged ; *Colectomy ; Colonic Neoplasms/*pathology ; Colonic Polyps/pathology/*surgery ; *Colonoscopy ; Female ; Follow-Up Studies ; Humans ; Male ; Middle Aged ; Multivariate Analysis ; Neoplasm Recurrence, Local/*diagnosis ; Retrospective Studies ; Risk Factors