• Biomedical Science Letters
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• v.18 no.4
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• pp.362-368
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• 2012

Enterotoxigenic Bacteroides fragilis (ETBF) is an intestinal commensal bacterium implicated as a risk factor for colon cancer. The key virulence factor is a secreted toxin called B. fragilis toxin (BFT). In this study we used an in vitro bioassay to examine the prevalence of ETBF in colonic washings from patients with colorectal polyps and normal control patients. We found that 9.3% of polyp patients and 10.9% of non-polyp patients harbored ETBF, respectively. A total of nine ETBF clinical isolates were isolated and confirmed to be positive for the BFT gene by PCR analysis and the ability to induce IL-8 secretion in the colonic epithelial cell line HT29/c1. Two of the ETBF clinical strains were characterized further in vitro and in vivo. We found that the two ETBF clinical isolates induced E-cadherin cleavage in HT29/c1 cells and promoted colonic inflammation in C57BL/6 mice. Our results indicate that the prevalence of ETBF in polyp patients were similar in non-polyp patients suggesting that ETBF carriage does not positively correlate to polyp incidence.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.22
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• pp.9801-9804
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• 2014

Background: Colorectal cancer is currently the third most common cancer in Indonesia, yet colonoscopy - the most accepted mode of screening to date - is not done routinely and national data are still lacking. Objective: To determine the detection rate of colorectal cancers and adenomas in unselected patients undergoing colonoscopy for various large bowel symptoms at the Digestive Disease and GI Oncology Centre, Medistra Hospital in Jakarta, Indonesia. Materials and Methods: Colonoscopy data from January 2009 to December 2012 were reviewed. New patients referred for colonoscopy were included. Data collected were patient demographic and significant colonoscopy findings such as the presence of hemorrhoids, colonic polyps, colonic diverticula, inflammation, and tumor mass. Histopathological data were obtained for specimens taken by biopsy. Associations between categorical variables were analyzed using chi-square test, while mean differences were tested using the t-test. Results: A total of, 1659 cases were included in this study, 889 (53.6%) of them being men. Polyps or masses were found in 495 (29.8%) patients while malignancy was confirmed in 74 (4.5%). Patients with a polyp or mass were significantly older (60.2 vs 50.8 years; p<0.001; t-test) and their presence was significantly associated with male gender (35.0% vs 23.9%; prevalent ratio [PR] 1.71; 95% confidence interval [CI] 1.38-2.12; p<0.001) and age >50 years (39.6% vs 16.6%; PR 3.29; 95% CI 2.59-4.12; p<0.001). Neoplastic lesions was found in 257 (16.1%), comprising 180 (11.3%) adenomas, 10 (0.6%) in situ carcinomas, and 67 (4.2%) carcinomas. Conclusions: Polyps or masses were found in 30% of colonoscopy patients and malignancies in 16.1%. These figures do not represent the nation-wide demographic status of colorectal cancer, but may reflect a potentially increasing major health problem with colorectal cancer in Indonesia.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.4
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• pp.1115-1118
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• 2012

Diallyl sulfide (DAS), a flavoring compound derived from garlic, is considered to have cancer chemopreventive potential in experimental animals and humans. This study was designated to examine possible chemopreventive effects of DAS on colon carcinogenesis using genetically engineered transgenic $Apc^{Min/+}$ mice, a well-established animal model for familial adenomatous polyposis (FAP) and sporadic colorectal cancer. Male C57BL/6J-$Apc^{Min/+}$ mice were divided into three groups. Animals of group 1 were placed on the basal diet (AIN-76A) as non-treated controls. Animals of groups 2 and 3 were given DAS-containing diets (in doses of 100 and 300 ppm, respectively). All mice were sacrificed at the end of week 10 of the experiment. Histopathological investigation revealed that the incidence of colonic polyps was decreased dose-dependently by 19% (13/16) in group 2 and by 32% (13/20) in group 3 compared to the 100% incidence (10/10) in group 1. The multiplicity of colonic polyps per mouse was also slightly decreased by DAS treatment ($1.88{\pm}0.35$ in group 2 and $1.63{\pm}0.36$ in group 3) compared to $2.00{\pm}0.39$ in group 1. On the other hand, there were no significant differences in the numbers of total polyps per mouse in the small intestine between the groups. Taken together, we suggest that DAS may exert promising inhibitory effects on colon carcinogenesis in the transgenic $Apc^{Min/+}$ mice.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.8
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• pp.4143-4147
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• 2016

Purpose: We evaluated all PET/CTs acquired for patients without a primary diagnosis of colorectal cancer, and compared results for those who had subsequent colonoscopy within 6 months, to assess the accuracy of FDG PET/CT for detection of incidental pre-malignant polyps and malignant colon cancers. Materials and Methods: Medical records of 9,545 patients who underwent F-18 FDG PET/CT studies over 3.5 years were retrospectively reviewed. Due to pre-existing diagnosis of colorectal cancer, 818 patients were excluded. Of the remainder, 157 patients had colonoscopy within 6 months (79 males; mean age 61). We divided the colon into 4 regions and compared PET/CT results for each region with colonoscopy and histopathologic findings. True positive lesions included colorectal cancer, villous adenoma, tubulovillous adenoma, tubular adenoma and serrated hyperplastic polyp/hyperplastic polyposis. Results: Of 157 patients, 44 had incidental colonic uptake on PET/CT (28%). Of those, 25 had true positive (TP) uptake, yielding a 48% positive predictive value (PPV); 9% (4/44) were adenocarcinoma. There were 23 false positive (FP) lesions of which 4 were hyperplastic polyp, one was juvenile polyp and 7 were explained by diverticulitis. Fifty eight patients had false negative PET scans but colonoscopy revealed true pre-malignant and malignant pathology, yielding 23% sensitivity. The specificity, negiative predictive value (NPV) and accuracy were 96%, 90% and 87%, respectively. The average SUVmax values of TP, FP and FN lesions were 7.25, 6.11 and 2.76, respectively. There were no significant difference between SUVmax of TP lesions and FP lesions (p>0.95) but significantly higher than in FN lesions (p<0.001). The average size (by histopathology and colonoscopy) of TP lesions was 18.1 mm, statistically different from that of FN lesions which was 5.9 mm (p<0.001). Fifty-one percent of FN lesions were smaller than 5 mm (29/57) and 88% smaller than 10 mm (50/57). Conclusions: The high positive predictive value of incidental focal colonic FDG uptake of 48% for colonic neoplasia suggests that colonoscopy follow-up is warranted with this finding. We observed a low sensitivity of standardly acquired FDG-PET/CT for detecting small polyps, especially those less than 5 mm. Clinician and radiologists should be aware of the high PPV of focal colonic uptake reflecting pre-malignant and malignant lesions, and the need for appropriate follow up.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.26 no.1
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• pp.15-22
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• 2023

Purpose: Total colonoscopy is recommended if colorectal polyps are clinically suspected. This study aimed to investigate the performance status of pediatric colonoscopic polypectomy in Korea. Methods: We surveyed pediatric endoscopic specialists who perform colonoscopic polypectomy in Korea using a questionnaire of 13 questions on pediatric colonoscopic polypectomy performance status. Results: The survey was conducted at 45 institutions, and 32 specialists (71.1%) responded. Among the respondents, 31.2% (10/32) said colonoscopy was performed in all age groups, while 12.5% (4/32) said sigmoidoscopy was performed in all age groups. Meanwhile, 56.2% (18/32) said that sigmoidoscopy was performed in young children, while colonoscopy was performed in older children. Among them, 38.9% (7/18) believe that 4-6 years were young, and 44.5% (8/18) believe that 7-9 years were young. Regarding surveillance examinations, 21.9% (7/32) said they would perform a surveillance colonoscopy or sigmoidoscopy in the future if less than five juvenile polyps were found in the colon. Meanwhile, if less than five adenomatous polyps were found in the colon, 93.8% (30/32) said they would perform surveillance colonoscopy or sigmoidoscopy in the future. Conclusion: More than half of the pediatric endoscopic specialists in Korea choose between a colonoscopy and sigmoidoscopy depending on the patient's age, contrary to the generally accepted recommendation of total colonoscopy if colorectal polyps are suspected in children and adolescents. In this survey, most pediatric endoscopists used the age range of 4-9 years as the reference age.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.4
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• pp.1361-1364
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• 2012

Background: Results of screening colonoscopy from Western countries reported adenoma detection rates (ADRs) of 30-40% while those from Asia had ADR as low as 10%. There have been limited data regarding screening colonoscopy in Thailand. The objectives of this study were therefore to determine polyp and adenoma detection rates in Thai people, to evaluate the incidence of colorectal cancer detected during screening colonoscopy and to determine the endoscopic findings of the polyps which might have some impact on endoscopists to perform polypectomy. Materials & Methods: This study was a retrospective electronic chart review of asymptomatic Thai adults who underwent screening colonoscopy in our endoscopic center from June 2007 to October 2010.Results: A total of 1,594 cases were reviewed. The patients had an average age of $58.3{\pm}10.5$ years (range 27-82) and 55.5% were female. Most of the cases (83.8%) were handled by staff who were endoscopists. A total of 488 patients (30.6%) were reported to have colonic polyps. Left-sided colon was the most common site (45.1%), followed by right-sided colon (36.5%) and the rectum (18%). Those polyps were removed in 97.5% of cases and 88.5 % of the polyps were sent for histopathology (data lost 11.5%). Two hundred and sixty three cases had adenomatous polyps, accounting for 16.5 % ADR. Advanced adenomas were detected in 43 cases (2.6%). Hyperplastic polyps were mainly located distal to the splenic flexure of the colon whereas adenomas were found throughout the large intestine. Ten cases (0.6%) were found to have colorectal cancer. Four advanced adenomas and two malignant polyps were reported in lesions ${\leq}$ 5 mm. Conclusion: The polyp detection rate, adenoma detection rate, advanced adenoma detection rate and colorectal cancer detection rate in the screening colonoscopy of Thai adults were 30.9%, 16.5%, 2.6% and 0.6% respectively. Malignant transformation was detected regardless of the size and location of the polyps. Therefore, new technology would play an important role indistinguishing polyps.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.4
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• pp.2119-2123
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• 2016

Background: There is an established link between obesity related metabolic derangement and colorectal cancer development. Recently, we developed a metabolic-colorectal cancer risk score. In this follow-up study, we studied its association with colorectal neoplasm by measuring two major metabolic syndrome biomarkers, leptin and adiponectin. Objectives: To evaluate the serum levels of leptin and adiponectin in patients with colorectal polyps and colorectal cancer and to determine any correlation with metabolic risk score. Results: In total, 130 individuals were studied: 30 controls without colonic pathology, 18 with colonic adenoma (CAP), and 82 with colorectal adenocarcinoma (CRC, 17 cases of T1-2 and 65 cases of T3-4). The metabolic risk scores in CAP and T1-2 CRC were higher than those in the controls and T3-4 CRC cases. There were no statistically significant differences in leptin levels among CAPs, CRCs, and controls. Both leptin and adiponectin levels reflected differences in body mass index and metabolic risk scores. Cases in the CAP group and early T-stage CRC groups had lower adiponectin levels (14.03 and 13.01 mg/ml, respectively) than the no polyps group (19.5mg/ml, p = 0.03). The average serum adiponectin level in the invasive cancer group (18.5 ng/ml) was comparable with that of the control group. Conclusions: The level of serum adiponectin was positively correlated with the metabolic risk score. Decreased serum adiponectin was significantly associated with the development of colorectal adenoma and early stage colorectal carcinoma.

• Journal of agricultural medicine and community health
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• v.39 no.3
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• pp.137-145
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• 2014

Objectives: Colonoscopy is a popular tool for screening for colon cancer throughout the world. The incidence of polypectomy and follow-up colonoscopy are persistently increasing but the studies about follow-up test after polypectomy are still lack of its domestic sources. This study is designed to look into the recurrence rate of colon polyps and risk factors after polypectomy. Methods: This is a retrospective study by reviewing medical charts of 147 patients who underwent polypectomy and follow-up colonoscopy from Jan. 2000 to Mar. 2008. The Kudo classification was used to describe the polyps found in the colonoscopy. The follow-up period was defined as the term between polypectomy and the first colonoscopy follow up. Results: Seventy six point two percent of the enrolled patient were male and the mean age was $56.5{\pm}8.1$. Mean follow-up period was $24.9{\pm}13.7$ (6 - 65) months. The cumulative recurrence rate of 1 year was 11.6%. The rate of 2 years was 36.7% and that of 3 years was 55.8%. The number of polyps was the factor which statistically showed significant relation of its recurrence rate. The histological morphology characteristic of polyps could be one independent factor which may be associated to the recurrence of polyps. Conclusions: The importance of colonoscopy follow up after polypectomy was clearly emphasized through the cumulative recurrence rate of 55.8%. Therefore, there is a need for more domestic studies with a large number of patients about the recurrence of polyps after polypectomy.

• Clinical and Experimental Pediatrics
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• v.53 no.9
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• pp.824-829
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• 2010

The safety and effectiveness of colonoscopy in the investigation of lower gastrointestinal tract pathology in children has been established for more than 2 decades in Korea. The skill and experience have since advanced to the point that both diagnostic and therapeutic colonoscopy are now routinely performed by most pediatric gastroenterologists. Pediatric colonoscopy differs significantly from its adult parallels in nearly every aspect including patient and parent management and preparation, selection criteria for sedation and general anesthetic, bowel preparation, expected diagnoses, instrument selection, imperative for terminal ileal intubation, and requirement for biopsies from macroscopically normal mucosa. Investigation of inflammatory bowel disease, whether for diagnosis or follow-up evaluation, and suspected colonic polyps are the most common indication for pediatric colonoscopy. The child who presents with signs and symptoms of lower gastrointestinal disorder should undergo colonoscopy with biopsy to make the diagnosis, as well as to help determine the appropriate therapy. This review introduces practical information on pediatric colonoscopy, the author's experiences, and the role of colonoscopic examination in the diagnosis and treatment of pediatric lower gastrointestinal disorders.

• Clinical Endoscopy
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• v.51 no.6
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• pp.534-540
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• 2018

From dye-assisted conventional chromoendoscopy to novel virtual chromoendoscopy, image-enhanced endoscopy (IEE) is continuously evolving to meet clinical needs and improve the quality of colonoscopy. Dye-assisted chromoendoscopy using indigo carmine or crystal violet, although slightly old-fashioned, is still useful to emphasize the pit patterns of the colonic mucosa and predict the histological structures of relevant lesions. Equipment-based virtual chromoendoscopy has the advantage of being relatively easy to use. There are several types of virtual chromoendoscopy that vary depending on the manufacturer and operating principle. IEE plays distinctive roles with respect to histologic characterization of colorectal polyps and prediction of the invasion depth of colorectal cancers. In addition, the newest models of IEE have the potential to increase adenoma and polyp detection rates in screening colonoscopy.