Search

Background/aims: The risk of recurrence of colorectal adenoma among obese individuals without metabolic abnormalities or in those with metabolically healthy obesity is largely unexplored. Therefore, we longitudinally investigated the risk of adenoma occurrence in individuals undergoing surveillance colonoscopy according to metabolic status and obesity., Methods: This retrospective cohort study included 16,872 Korean adults who underwent their first screening colonoscopy between 2003 and 2012 and who then underwent follow-up colonoscopy until 2017. Participants were categorized into a metabolically healthy nonobese group (reference group), a metabolically healthy obese group, a metabolically abnormal nonobese group, and a metabolically abnormal obese group. Hazard ratios (HRs) for adenoma recurrence compared to the reference group were calculated in each group., Results: During a median follow-up duration of 47.3 months (interquartile range, 35.6 to 58.9 months), 3,673 (21.8%) and 292 (1.73%) participants developed adenoma and advanced adenoma, respectively. When age, sex, smoking, alcohol consumption, family history of colorectal cancer, and baseline adenoma risk were adjusted, the risk of adenoma recurrence was increased in metabolically healthy obese individuals (HR, 1.33; 95% confidence interval [CI], 1.12 to 1.57) and metabolically abnormal obese individuals (HR, 1.18; 95% CI, 1.08 to 1.30) but not in metabolically abnormal nonobese individuals (HR, 1.03; 95% CI, 0.94 to 1.13)., Conclusions: In this study, metabolically healthy obese individuals and metabolically abnormal obese individuals exhibited increased risks of occurrence of colorectal adenoma diagnosed by surveillance colonoscopy. This finding implies that obesity itself, even without metabolic abnormalities, is associated with an increased risk of adenoma recurrence.

Background and Aim: In addition to index colonoscopy findings, demographic parameters including age are associated with the risk of metachronous advanced colorectal neoplasia. Here, we aimed to develop a risk scoring model for predicting advanced colorectal neoplasia (ACRN) during surveillance using a combination of clinical factors and index colonoscopy findings., Methods: Patients who underwent the removal of one or more adenomas and surveillance colonoscopy were included. A risk scoring model for ACRN was developed using the Cox proportional hazard model. Surveillance interval was determined as a time point exceeding 4% of the cumulative ACRN incidence in each risk group., Results: Of 9591 participants, 4725 and 4866 were randomly allocated to the derivation and validation cohorts, respectively. Age, abdominal obesity, advanced adenoma, and ≥ 3 adenomas at index colonoscopy were identified as risk factors for metachronous ACRN. Based on the regression coefficients, point scores were assigned as follows: age, 1 point (per 1 year); abdominal obesity, 10 points; advanced adenoma, 10 points; and ≥ 3 adenomas, 15 points. Patients were classified into high-risk (≥ 80 points), moderate-risk (50-79 points), and low-risk (30-49 points) groups. In the validation cohort, the high-risk and moderate-risk groups showed a higher risk of ACRN than the low-risk group (hazard ratio [95% confidence interval]: 7.11 [4.10-12.32] and 1.58 [1.09-2.30], respectively). Two-, 4-, and 5-year surveillance intervals were recommended for the high-risk, moderate-risk, and low-risk groups, respectively., Conclusions: Our proposed model may facilitate effective risk stratification of ACRN during surveillance and the determination of appropriate surveillance intervals., (© 2020 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.)

Background and Aim: Sarcopenia has been suggested to be associated with chronic inflammation and insulin resistance. This study aimed to evaluate whether low muscle mass is associated with the incidence and recurrence of advanced colorectal adenoma., Methods: We conducted a cohort study including 14 701 participants who underwent first-time screening colonoscopy between 2003 and 2012 and follow-up colonoscopy until 2017. Skeletal muscle mass was measured using a bioelectrical impedance analyzer and divided by body weight to calculate the skeletal muscle mass index (SMI)., Results: During a median 47 (interquartile range, 35-58) months of follow-up, overall and advanced adenoma developed in 2988 (20.3%) and 207 (1.41%) participants, respectively. In multivariate analysis using models adjusted for baseline adenoma risk, lifestyle factors, markers for insulin resistance and chronic inflammation, and metabolic syndrome, decreasing SMI quartiles were associated with increased risk of occurrence of advanced adenoma and overall adenoma. The adjusted hazard ratios (95% confidence intervals) comparing SMI quartiles 3, 2, and 1 to quartile 4 were 1.57 (1.03-2.41), 1.22 (0.78-1.92), and 1.77 (1.13-2.76), respectively, for advanced adenoma (P for trend = 0.049) and 1.05 (0.95-1.17), 1.09 (0.98-1.21), and 1.26 (1.13-1.41), respectively, for overall adenoma (P for trend < 0.001)., Conclusions: In this large cohort with long-term colonoscopy follow-up, low relative muscle mass was associated with increased risk of occurrence of advanced adenoma and overall adenoma at follow-up colonoscopy, independent of metabolic and inflammatory markers. Timely and thorough surveillance colonoscopy may be emphasized in such populations., (© 2020 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.)

Background and Aims: Serrated polyp detection rate (SDR) is a potential quality indicator for preventing colorectal cancer associated with the serrated pathway. Using clinically significant SDR (CSSDR) has been suggested based on clinically significant serrated polyp's ability to be colorectal cancer precursors. Correlations between CSSDR and simpler SDRs, other than proximal SDR, have not yet been studied. We aimed to investigate which simpler SDR indicator is most relevant to CSSDR or adenoma detection rate (ADR) and provide benchmark data., Methods: We analyzed 26 627 colonoscopies performed by 30 endoscopists. Clinically significant serrated polyps were defined as any sessile serrated adenoma/polyp or traditional serrated adenoma, hyperplastic polyps ≥ 5 mm in the proximal colon, or hyperplastic polyps ≥ 10 mm anywhere in the colon. Correlation of CSSDR and ADR with other simple SDRs, SDR-pathology (sessile serrated adenoma/polyp or traditional serrated adenoma), SDR-size (≥ 10 mm), and SDR-location (proximal location) was analyzed using Pearson's correlation test and Steiger's z-test., Results: The CSSDR was 1.7% to 13.2% (mean = 6.1%). The correlation coefficient of CSSDR/SDR-size was 0.91 (P < 0.01), which was higher than that of CSSDR/SDR-location (0.64, P < 0.01) (0.91 vs 0.61, P < 0.01). The correlation coefficient of ADR/CSSDR and ADR/SDR-location was 0.41 (P < 0.01) and 0.81 (P < 0.01), respectively. For ADR ≥ 25%, endoscopists' median screening CSSDR was 5.4%, while SDR-location and SDR-size were 10.9% and 2.2%, respectively., Conclusion: Large SDR could be a simple proxy for CSSDR, in addition to proximal SDR. Large SDR and proximal SDR benchmarks of 2.2% and 10.9% may guide adequate serrated polyp detection with uniform definitions and simpler calculations., (© 2020 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.)

Background and Aims: Current postpolypectomy guidelines classify 1 to 2 diminutive (1-5 mm) nonadvanced adenomas (NAAs) and 1 to 2 small (6-9 mm) NAAs as low-risk adenomas and recommend the same surveillance interval for both lesions. We compared the risk of metachronous advanced colorectal neoplasia (ACRN) for both groups., Methods: We studied 8602 patients who underwent removal of ≥1 NAA and follow-up colonoscopic surveillance. Patients were categorized into 4 groups based on size and number of baseline NAAs: group 1, ≤2 diminutive NAAs (n = 6379); group 2, ≤2 small NAAs (n = 1672); group 3, ≥3 diminutive NAAs (n = 293); and group 4, ≥3 small NAAs (n = 258). Size was classified based on the largest NAA., Results: The 5-year cumulative incidence rates of metachronous ACRN in groups 1, 2, 3, and 4 were 2.7%, 5.1%, 10.7%, and 15.1%, respectively. Groups 2, 3, and 4 had a higher risk of metachronous ACRN than group 1. Compared with group 1, the adjusted hazard ratios for metachronous ACRN were 2.06 (95% confidence interval [CI], 1.46-2.91) for group 2, 2.75 (95% CI, 1.53-4.96) for group 3, and 4.49 (95% CI, 2.62-7.70) for group 4. However, the risk of metachronous ACRN was not significantly different between groups 3 and 4 (adjusted hazard ratio, 1.62; 95% CI, .76-3.44)., Conclusions: Among patients with ≤2 NAAs, patients with 1- to 5-mm NAAs had a lower risk of metachronous ACRN than those with 6- to 9-mm NAAs. The guidelines should consider extending surveillance intervals in patients with ≤2 diminutive NAAs., (Copyright © 2020 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.)

Introduction: Current post-polypectomy guidelines recommend a 3-year surveillance interval for ≥3 nonadvanced adenomas (NAAs) without discrimination between diminutive (1-5 mm) and small (6-9 mm) adenomas. We compared the risk of metachronous advanced colorectal neoplasia (ACRN) among these groups., Methods: We studied 9,733 patients who underwent ≥1 adenoma removal and follow-up colonoscopic surveillance. Patients were classified based on baseline adenoma characteristics: group 1, 1-2 NAAs (n = 8,051); group 2, ≥3 diminutive NAAs (n = 293); group 3, ≥3 small NAAs (n = 258); and group 4, advanced adenomas (AAs) (n = 1,131)., Results: The mean age of the study population was 45.8 ± 8.2 years. In group 4, most patients (94.5%) had 1 AA. The 3- and 5-year cumulative incidence rates of metachronous ACRN in groups 1, 2, 3, and 4 were 0.9%, 2.8%, 3.5%, and 4.0% and 3.1%, 10.7%, 15.1%, and 8.5%, respectively. Groups 2, 3, and 4 had a higher risk of metachronous ACRN than group 1. Compared with those for group 1, adjusted hazard ratios (95% confidence interval) for metachronous ACRN were 2.07 (1.16-3.68), 3.29 (1.94-5.56), and 2.73 (2.00-3.72) for groups 2, 3, and 4, respectively. However, this relationship was statistically insignificant between groups 2, 3, and 4. Compared with those for group 2, adjusted hazard ratios (95% confidence intervals) for groups 3 and 4 were 1.59 (0.76-3.30) and 1.32 (0.72-2.42), respectively, and 0.83 (0.47-1.46) for group 4 compared with group 3. The results of patients aged ≥50 years were identical to those of all patients., Discussion: Risk of metachronous ACRN was not different between patients aged ≥50 years who underwent polypectomy of ≥3 diminutive NAAs, ≥3 small NAAs, and AA, thus supporting current guidelines that recommend a uniform surveillance interval for these lesions.

Background/aims: Limited data are available regarding the association between age at menarche and the risk of colorectal adenoma. Therefore, we aimed to evaluate the relationship between reproductive factors including age at menarche and the risk of colorectal adenoma., Methods: A cross-sectional study was performed on asymptomatic female subjects who underwent colonoscopy between 2010 and 2014 as part of a comprehensive health screening program in Korea. The association between reproductive factors including age at menarche and the presence of adenomas was assessed using multivariate logistic regression analysis., Results: Among 32,620 asymptomatic female subjects, the proportion of patients with menarche at 10 to 11, 12 to 13, 14 to 15, 16 to 17, and 18 to 19 years of age was 4.1%, 31.7%, 45.4%, 14.9%, and 4.0%, respectively. Age at menarche was not significantly associated with the risk of any adenoma (adjusted odds ratio [AOR], 0.99; 95% confidence interval [CI], 0.97 to 1.02; p = 0.500) or advanced adenoma (AOR, 0.98; 95% CI, 0.91 to 1.04; p = 0.468) after adjusting for confounding factors. Age at menarche was not significantly associated with the risk of adenoma even among similar age groups. In addition, parity, use of female hormones, and menopause were not associated with the risk of adenoma., Conclusion: Age at menarche, parity, use of female hormones, and menopause were not significantly associated with the risk of colorectal adenoma. Our findings indicate that reproductive factors including age at menarche do not affect the development of colorectal adenoma.

Background and Aims: We aimed to develop risk stratification models for advanced colorectal neoplasia (ACRN) and colorectal cancer (CRC) based on fecal hemoglobin (f-Hb) concentration and clinical risk factors., Methods: We reviewed screenees aged ≥50 years who underwent fecal immunochemical test (FIT) and colonoscopy and developed risk-scoring models for ACRN and CRC using logistic regression analysis. Participants were classified into low- (risk lower than that in FIT-negative individuals), intermediate- (risk higher than that in FIT-negative but lower than that in FIT-positive individuals), high- (risk similar to that in FIT-positive individuals), and very-high- (risk higher than that in FIT-positive individuals) risk groups., Results: Of 3733 participants, 367 (9.8%) and 70 (1.9%) had ACRN and CRC, respectively. On multivariable analysis, age (ß = .043/y), former smoker (ß = .401), current smoker (ß = .841), diabetes (ß = .097), and square root of f-Hb concentration (ß = .071) were significantly associated with ACRN. In terms of CRC, age (ß = .035/y) and square root of f-Hb concentration (ß = .004) were associated factors. After point assignments based on the regression coefficient, we could classify screenees as low-, intermediate-, high-, and very-high-risk groups. ACRN was identified in 2.9%, 5.3%, 16.2%, and 35.7% of screenees in the low-, intermediate-, high-, and very-high-risk groups, respectively. CRC was identified in .1%, .5%, 3.9%, and 11.1% of screenees in the low-, intermediate-, high-, and very-high-risk groups, respectively., Conclusions: The proposed models can effectively stratify the risk for ACRN and CRC and provide accurate information on this risk in individuals who undergo FIT., (Copyright © 2019 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.)

Background: Current postpolypectomy surveillance guidelines are based on studies in patients aged ≥50 years. Equal application of the guidelines in patients aged < 50 years may be unreasonable. We aimed to determine an appropriate surveillance interval after adenoma removal in patients aged < 50 years., Methods: We studied 10,013 patients who underwent ≥ 1 adenoma removal and follow-up colonoscopy. The cumulative risk of metachronous advanced colorectal neoplasia (ACRN) was compared among the eight groups based on age (30-39, 40-44, 45-49 and ≥ 50 years) and baseline adenoma characteristics (low- [LRA] and high-risk adenoma [HRA])., Results: The risk of metachronous ACRN in patients aged 30-39 and 40-44 years with HRA was comparable to that in those aged ≥ 50 years with LRA ( P = 0.839 and P = 0.381, respectively). However, the risk in those aged 45-49 years with HRA was higher than in those aged ≥ 50 years with LRA ( P = 0.003), and the risk was not significantly different from that in those aged ≥ 50 years with HRA ( P = 0.092). Additionally, the 5-year cumulative risk in those aged 45-49 years with LRA was not significantly different from that in those aged ≥ 50 years with LRA., Conclusion: The postpolypectomy surveillance interval can be extended up to 5 years in patients aged 30-44 years with HRA, similar to those aged ≥ 50 years with LRA. However, the interval in patients aged 45-49 years with HRA and LRA should be 3 and 5 years, respectively, similar to those aged ≥ 50 years., Competing Interests: Disclosure: The authors have no potential conflicts of interest to disclose.

Background and Aim: There are no established guidelines on screening strategies for persons with a family history of colorectal cancer (CRC) in Korea. We aimed to evaluate the age-specific risk of colorectal neoplasia according to family history of CRC., Methods: Participants who underwent screening colonoscopy were included. Age-specific prevalence of non-advanced adenoma (NAA) and advanced colorectal neoplasia (ACRN) was calculated according to family history of CRC., Results: Among 35 997 participants, 1339 (3.7%) had a family history of CRC in first-degree relatives. A family history of CRC was an independent risk factor for NAA (adjusted odds ratio [AOR] 1.33, 95% confidence interval [CI] 1.16-1.52). In the subgroup analysis by age, family history of CRC was a risk factor for NAA in the 50-59 and ≥ 60 years groups (AOR [95% CI]: 1.42 [1.04-1.91] and 2.33 [1.34-4.09], respectively), but not in the 30-39 and 40-49 years groups. In the curve of age-specific prevalence of NAA, the gap of the prevalence between the family history and non-family history groups began to widen after the mid-50s. In cases of ACRN, a family history of CRC was not a risk factor in the entire age group (AOR 1.16, 95% CI 0.75-1.70). In the curve of age-specific prevalence of ACRN, however, the gap of the prevalence between the family history and non-family history groups began to widen after the early 60s., Conclusion: Although a family history of CRC is a risk factor for NAA, it may affect NAA development from the mid-50s and ACRN development from the early 60s., (© 2018 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.)

Background/aims: There has been no evidence for the necessity of endoscopy in asymptomatic young men with iron deficiency anemia (IDA). To determine whether endoscopy should be recommended in asymptomatic young men with IDA, we compared the prevalence of gastrointestinal (GI) lesions between young men (< 50 years) with IDA and those without IDA., Methods: We conducted a case-control study on asymptomatic young men aged < 50 years who underwent both esophagogastroduodenoscopy (EGD) and colonoscopy as part of a health checkup between 2010 and 2014., Results: Of 77,864 participants, 128 (0.16%) had IDA and 512 subjects without IDA were matched for several variables including age. Young men with IDA had a significantly higher proportion of colorectal cancer (CRC) (0.8% vs. 0.0%, p = 0.045), villous adenoma (0.8% vs. 0.0%, p = 0.045), and inflammatory bowel disease (IBD; 2.3% vs. 0.4%, p = 0.025) than those without IDA. Additionally, the prevalence of advanced colorectal neoplasia (ACRN) tended to be higher in subjects with IDA than in those without IDA (3.1% vs. 1.0%, p = 0.084). The prevalence of significant lower GI lesions including ACRN and IBD was higher in subjects with IDA than in those without IDA (5.5% vs. 1.4%, p = 0.011). Regarding upper GI lesions, a positive association with IDA was observed only for gastric ulcer (4.7% vs. 1.0%, p = 0.011)., Conclusion: GI lesions including CRC, villous adenoma, IBD, and gastric ulcer were more common in asymptomatic young men with IDA. Our results suggest that EGD and particularly colonoscopy should be recommended even in asymptomatic young men with IDA.

Background and Aims: Current guidelines define postpolypectomy surveillance intervals in patients aged ≥50 years. The risk of metachronous colorectal neoplasia (CRN) and the optimal postpolypectomy surveillance interval in patients aged <50 years remain unclear. We compared the risk of metachronous CRN in patients aged 30 to 39, 40 to 49, and ≥50 years., Methods: We studied patients who underwent ≥1 adenoma removal between 2010 and 2014 and follow-up colonoscopic surveillance until 2017., Results: Among 10,014 patients studied, 3242, 4606, and 2166 were 30 to 39, 40 to 49, and ≥50 years old, respectively. After high-risk adenoma removal, the 3-year risk of metachronous advanced CRN (ACRN) in patients aged 30 to 39 and 40 to 49 years was lower than in patients ≥50 years old (1.9% and 3.6% vs 8.1%, respectively; P < .001 and .008). After low-risk adenoma removal, the 5-year risk of metachronous ACRN in patients aged 30 to 39 and 40 to 49 years was lower than in patients ≥50 years old (2.8% and 3.3% vs 5.9%, respectively; P = .010 and .031). The risk of metachronous ACRN or ≥3 adenomas in patients aged 30 to 39 years was significantly lower than in patients aged 40 to 49 years. Age remained significantly associated with the risk of metachronous ACRN despite adjustments for potential confounders., Conclusions: The risk of metachronous ACRN was lower in patients aged <50 years than in those aged ≥50 years; thus, the postpolypectomy surveillance interval may be extendable to >3 and 5 years in high-risk and low-risk adenoma groups, respectively, in patients aged <50 years., (Copyright © 2018 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.)

Background and Aims: Individuals without a family history of colorectal cancer (CRC) are screened uniformly despite interpersonal risk. To assess individual risk, we examined the age-specific prevalence of advanced colorectal neoplasia (ACRN) according to clinical risk factors and fecal immunochemical test (FIT) results., Methods: Participants without a family history of CRC who underwent screening colonoscopies and FITs were included. Clinical risk factors for ACRN were identified by using a logistic regression model. Point scores were assigned to each associated factor based on a regression coefficient., Results: A total of 34,658 participants were included. Age, male sex, smoking, and obesity were identified as risk factors. One-, 2-, and 1-point scores were assigned to male sex, smoking, and obesity, respectively. The prevalence of ACRN in individuals with 0, 1, and ≥2 risk score points was 1.4%, 1.6%, and 2.9% among those aged 50 to 51 years and 3.1%, 5.5%, and 7.5% among those aged ≥66 years, respectively. Among FIT-positive individuals, the prevalence of ACRN was 11.0% and 21.2% in those aged between 50 and 51 years and those aged ≥66 years, respectively. Among FIT-negative individuals with ≥2 risk score points, the prevalence of ACRN was 2.5% and 6.0% among those aged 50 to 51 years and those aged ≥66 years, respectively., Conclusion: If the clinical risk score is ≥2 points (persons with smoking history or obese men), early colonoscopy may be recommended, even with no family history of CRC. Additionally, FIT may be an appropriate initial screening modality for average-risk individuals if the clinical risk score is 0 to 1., (Copyright © 2018 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.)

Background/aims: Although the patients with multiple advanced adenomas (AA) in index colonoscopy may have an increased risk for subsequent advanced colorectal neoplasia (CRN), the current guidelines do not consider this factor. We aimed to compare the risk of metachronous advanced CRN according to the number of AAs., Methods: A total of 2250 patients with ≥1 adenoma at index colonoscopy were included. The patients were divided according to the number of AAs (1, 2 and ≥3 AAs). The relative and 3-year absolute risk of metachronous advanced CRN was compared between the AA groups., Results: The relative risk of metachronous advanced CRN was higher in the patients with ≥3 AAs than in the patients with one AA (16.7% vs. 6.8%, p = 0.004). The 3-year absolute risk of metachronous advanced CRN was higher in the patients with ≥3 AAs than in the patients with 1-2 AA (19.4% vs. 6.9%, p = 0.04). Having ≥3 AAs (odds ratio, 5.42; 95% confidence interval 1.75-16.83) was a significant risk factor for developing advanced CRN., Conclusions: The risk of metachronous advanced CRN in the patients with ≥3 AAs was higher than that in the patients with one or two AAs. More intensive surveillances might be needed for these patient groups., (Copyright © 2018 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.)

Background and Aims: The U.K. guidelines for risk stratification after colon polypectomy differ from the U.S. guidelines in 2 ways: the U.K. guidelines consider ≥5 adenomas as high risk and do not consider histology (villous or high-grade dysplasia) in the assessment. Thus, we aimed to investigate the risk of advanced colorectal neoplasm (CRN) by categorized risk groups, considering both ≥5 adenomas and histology., Methods: A total of 2570 patients with ≥1 adenoma at index colonoscopy were included. The patients were divided into 6 groups: group 1, 1 to 2 non-advanced adenomas (non-AAs) ≥10 mm or high-grade dysplasia or villous adenoma; group 1A, 1 to 2 adenomas with ≥1 advanced adenoma (AA); group 2, 3 to 4 non-AAs; group 2A, 3 to 4 adenomas with ≥1 AA; group 3, ≥5 non-AAs; and group 3A, ≥5 adenomas with ≥1 AA. The risk of advanced CRN at 3 years was compared among the 6 groups., Results: Group 3A showed a higher risk of advanced CRN (9.6%) than group 3 (4.5%; P = .03) and group 1A (4.6%; P < .001). The risk of advanced CRN in group 3 (4.5%) showed no difference compared with group 1A (4.6%; P = .91) or group 2A (6.8%; P = .25). There was no difference between group 1 and group 2 in the risk of advanced CRN (1.7% vs 2.2%; P = .22). More than 1 AA at index colonoscopy was an independent risk factor for advanced CRN., Conclusion: More-intensive surveillance than the 3-year interval for patients with ≥5 adenomas with ≥1 AA and less-intensive surveillance than the 3-year and 1-year intervals for those with 3 to 4 non-AAs and ≥5 non-AAs, respectively, might be suggested., (Copyright © 2018 American Society for Gastrointestinal Endoscopy. Published by Elsevier Inc. All rights reserved.)

Background: Family history of cancers at different sites except for colorectum has not been evaluated as a risk factor for colorectal neoplasia (CRN)., Aims: To investigate CRN risk according to family history of cancers at 12 different sites, including stomach and colorectum., Methods: A cross-sectional study was performed on 139,497 asymptomatic Koreans who underwent colonoscopy as part of a health check-up., Results: The mean age of the study population was 41.6 and the prevalence of CRN was 16.3%. Multivariate analyses revealed that family histories of CRC (adjusted odds ratio; confidence interval, 1.26; 1.17-1.35) and gastric cancer (1.07; 1.01-1.13) were independent risk factors for CRN. Notably, the risk of CRN increased even more for participants with family histories of both CRC and gastric cancer (1.38; 1.12-1.70). Family history of CRC was associated with risk of CRN in participants aged both <50 and ≥50 years, whereas family history of gastric cancer was associated with risk of CRN in participants aged <50 years (1.22; 1.14-1.30), but not in participants aged ≥50 years (1.08; 0.99-1.18)., Conclusions: Family history of gastric cancer was an independent risk factor for CRN, especially in those aged <50years. Persons with family histories of gastric cancer and CRC, especially those with family histories of both, may need to begin colonoscopy earlier., (Copyright © 2017 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.)

Purpose: Limited data are available regarding the associations between parameters of glucose and lipid metabolism and the occurrence of metachronous adenomas. We investigated whether these parameters affect the occurrence of adenomas detected on surveillance colonoscopy., Materials and Methods: This longitudinal study was performed on 5289 subjects who underwent follow-up colonoscopy between 2012 and 2013 among 62171 asymptomatic subjects who underwent an initial colonoscopy for a health check-up between 2010 and 2011. The risk of adenoma occurrence was assessed using Cox proportional hazards modeling., Results: The mean interval between the initial and follow-up colonoscopy was 2.2±0.6 years. The occurrence of adenomas detected by the follow-up colonoscopy increased linearly with the increasing quartiles of fasting glucose, hemoglobin A1c (HbA1c), insulin, homeostasis model assessment of insulin resistance (HOMA-IR), and triglycerides measured at the initial colonoscopy. These associations persisted after adjusting for confounding factors. The adjusted hazard ratios for adenoma occurrence comparing the fourth with the first quartiles of fasting glucose, HbA1c, insulin, HOMA-IR, and triglycerides were 1.50 [95% confidence interval (CI), 1.26-1.77; p(trend)<0.001], 1.22 (95% CI, 1.04-1.43; p(trend)=0.024), 1.22 (95% CI, 1.02-1.46; p(trend)=0.046), 1.36 (95% CI, 1.14-1.63; p(trend)=0.004), and 1.19 (95% CI, 0.99-1.42; p(trend)=0.041), respectively. In addition, increasing quartiles of low-density lipoprotein-cholesterol and apolipoprotein B were associated with an increasing occurrence of adenomas., Conclusion: The levels of parameters of glucose and lipid metabolism were significantly associated with the occurrence of adenomas detected on surveillance colonoscopy. Improving the parameters of glucose and lipid metabolism through lifestyle changes or medications may be helpful in preventing metachronous adenomas., Competing Interests: The authors have no financial conflicts of interest.

Background: Several studies have reported that the fecal immunochemical test (FIT) less sensitively detects proximal advanced neoplasia (AN) compared to distal AN. Low threshold value use may improve proximal AN detection., Aim: To investigate whether FIT diagnostic accuracy for AN is different according to AN location and to compare FIT accuracy in proximal AN detection using different threshold values., Methods: This retrospective study was conducted in a university hospital in Korea from June 2013 to May 2015. Out of 34,547 participants who underwent FITs, 3990 subjects aged ≥50 years who also underwent colonoscopies were analyzed. The FIT diagnostic accuracy for AN with differing locations (proximal vs. distal) and threshold values (20, 15, and 10 mcg Hb/g feces) were assessed., Results: The sensitivity, specificity, positive predictive value, and negative predictive value of FIT in AN detection were 42.2, 84.3, 24.1, and 92.5 %, respectively. The FIT sensitivity for proximal AN detection was significantly lower than that for distal AN detection (32.7 and 49.0 %, respectively; P = 0.001). Lowering FIT threshold values tended to increase the sensitivity for proximal AN, whereas it significantly decreased the specificity for proximal AN. As a result, there was no significant difference in the accuracy for proximal AN detection (80.1, 79.3, and 78.1 % for 20, 15, and 10 mcg Hb/g feces, respectively; P = 0.107)., Conclusions: FIT was less sensitive in proximal AN detection than distal AN detection. Lowering the FIT cutoff threshold did not increase the accuracy for proximal AN detection. New biomarker development for colorectal cancer screening is required to improve proximal ACRN diagnostic accuracy.

Background: Obesity is reportedly a risk factor for colorectal adenoma. However, the influence of weight change and obesity on colorectal adenoma recurrence is unclear., Aim: To investigate whether weight change and obesity are associated with recurrence and development of colorectal adenoma., Patients and Methods: Of 62,171 asymptomatic subjects who underwent a colonoscopy for a heath checkup between 2010 and 2011, this longitudinal study was performed with the 5297 subjects who underwent another colonoscopy between 2012 and 2013. The risk of recurrence or development of adenoma according to quartiles of weight change (<-1.6, -1.6 to 0.1, 0.2-1.8, and ≥1.9 kg) and baseline BMI categories (<25, 25-29, and ≥30 kg/m(2)) was assessed using Cox proportional hazards modeling., Results: The average period between visits 1 and 2 was 2.2 ± 0.6 years. Among the 2176 subjects with adenomas, the risk of recurrence of any adenoma increased with increasing weight change quartiles (p for trend = 0.030), whereas the risk of recurrence of advanced adenoma was not associated with weight change (p for trend = 0.852). The risk of recurrence of advanced adenoma increased with increasing baseline BMI categories (p for trend = 0.029). Among 3121 subjects with no adenoma, the risk of developing any adenoma increased with increasing baseline BMI categories (p for trend <0.001). However, the risk of developing any or advanced adenoma was not associated with weight change., Conclusions: Weight change over 2.2 years affected adenoma recurrence and obesity was related to advanced adenoma recurrence and adenoma development.

Aim: To compare the risk of developing advanced colorectal neoplasm (ACRN) according to age in Koreans., Methods: A total of 70428 Koreans from an occupational cohort who underwent a colonoscopy between 2003 and 2012 at Kangbuk Samsung Hospital were retrospectively selected. We evaluated and compared odds ratios (OR) for ACRN between the young-adults (YA < 50 years) and in the older-adults (OA ≥ 50 years). ACRN was defined as an adenoma ≥ 10 mm in diameter, adenoma with any component of villous histology, high-grade dysplasia, or invasive cancer., Results: In the YA group, age (OR = 1.08, 95%CI: 1.06-1.09), male sex (OR = 1.26, 95%CI: 1.02-1.55), current smoking (OR = 1.37, 95%CI: 1.15-1.63), family history of colorectal cancer (OR = 1.46, 95%CI: 1.01-2.10), diabetes mellitus related factors (OR = 1.27, 95%CI: 1.06-1.54), obesity (OR = 1.23, 95%CI: 1.03-1.47), CEA (OR = 1.04, 95%CI: 1.01-1.09) and low-density lipoprotein-cholesterol (OR = 1.01, 95%CI: 1.01-1.02) were related with an increased risk of ACRN. However, age (OR = 1.08, 95%CI: 1.06-1.09), male sex (OR = 2.12, 95%CI: 1.68-2.68), current smoking (OR = 1.38, 95%CI: 1.12-1.71), obesity (OR = 1.34, 95%CI: 1.09-1.65) and CEA (OR = 1.05, 95%CI: 1.01-1.09) also increased the risk of ACRN in the OA group., Conclusion: The risks of ACRN differed based on age group. Different colonoscopic screening strategies are appropriate for particular subjects with risk factors for ACRN, even in subjects younger than 50 years.

Background/aims: Adenoma detection rate (ADR) is widely used as an index of colonoscopy quality management. Although advanced adenomas can be found less frequently than non-advanced adenomas, advanced adenomas have a higher clinical significance during screening for colorectal cancer. The aim of this study was to investigate the correlation between advanced and non-advanced ADR among colonoscopists., Methods: This study is an observational study of a cohort of patients undergoing screening colonoscopy between 2009 and 2010. We collected the data on patients' characteristics and colonoscopic findings. The detection rates of adenoma and advanced adenoma were calculated. Logistic regression was used to determine the effects of variables on advanced adenoma detection, and spearman's rank-order correlation was used to evaluate the relationship between advanced ADR and ADR., Results: A total of 561 patients underwent screening colonoscopy by 18 experienced colonoscopists. Most colonoscopists had adequate (>20%) ADRs. Logistic regression showed that increased patient age (OR 1.07 per 1 year increase, 95% CI 1.009-1.133, p=0.023) and male gender (OR 1.860, 95% CI 0.764-4.529, p=0.171) were associated with advanced ADR. When colonoscopists were divided into two groups on the basis of advanced ADR of 5%, ADR was also significantly higher in the group having higher level of advanced ADR. However, there was no correlation between advanced ADR and ADR among colonoscopists as an individual., Conclusions: Colonoscopists' advanced ADRs were independent of their ADRs, indicating that advanced ADR could be quite low even among colonoscopists with acceptable ADRs. Thus, there seems to be a limitation in using ADR as an adequate index of colonoscopy quality management.

Background and Study Aims: Cold biopsy forceps polypectomy (CBP) is commonly used for the removal of diminutive polyps; however, evidence for the efficacy of CBP is lacking. The aim of this study was to evaluate the adequacy of resection of diminutive polyps and to identify predictors for complete resection using CBP., Patients and Methods: This was a prospective study from a tertiary referral hospital in Korea. A total of 196 patients were screened, and 65 patients with diminutive polyps were enrolled. CBP was used to resect diminutive polyps until no polyp was visible by chromoendoscopy using indigo carmine spray. Each polyp base was then resected using endoscopic mucosal resection (EMR) with a 1-3-mm free margin. CBP and EMR specimens were sent to the histopathology department for the evaluation of the completeness of the resection. Cross sections of the EMR specimens made at 1-mm intervals were examined by a pathologist., Results: A total of 86 diminutive polyps were available for assessment. Overall, 90.7% (78/86) of the diminutive polyps were completely resected using CBP (95%CI 84.6-96.8%). The complete resection rate for all diminutive adenomas was 92.3 % (60/65; 95%CI 85.8-98.8%) and for 1-3-mm adenomas 100% (95%CI 81.5-100%). Polyp size, histology, and location, and number of biopsies were not different between the complete and incomplete resection groups., Conclusions: In this small study approximately 90 % of all diminutive polyps and 100% of 1-3-mm adenomatous polyps were completely resected using CBP and chromoendoscopy. CBP appears to be adequate for the resection of the majority of diminutive polyps, especially small sized adenomas (≤ 3 mm) if no residual tissue is visible by chromoendoscopy., (© Georg Thieme Verlag KG Stuttgart · New York.)

Background/aims: This study was designed to determine the prevalence of microsatellite instability (MSI) among colorectal adenomas detected in patients ≤ 40 years of age and to compare the prevalence of MSI in young (≤ 40 years) and older (>40 years) patients with colorectal adenomas. Additionally, we attempted to identify the underlying cause of MSI in these patients., Methodology: We prospectively tested for the presence of MSI using five NCI markers in samples from the two patient groups. The frequency of MSI was compared and the underlying causes of MSI were determined by methylation specific PCR and germ-line mutation analysis for mismatch repair genes., Results: The frequency of MSI was higher in the ≤ 40 group than the >40 group (31.4% and 6.4%, respectively, p=0.0004). The MSI-high pattern was also more prevalent in the ≤ 40 group than the >40 group (15.7% and 2.5%, respectively, p=0.014). The hypermethylated hMLH1 gene was demonstrated in 7/8 (87.5%) patients with MSI-high in the ≤ 40 group and in 1/2 (50.0%) patients with MSI-high in the >40 group. No study subject showed a germline mutation of hMLH1 or hMSH2., Conclusions: MSI-high was more frequent in young (≤ 40 years) patients with colorectal adenoma than in older (>40 years) patients. Hypermethylation of the hMLH1 gene appears to be an important cause of MSI-high in these patients.

Background/aims: Colorectal cancer (CRC) screening using stool DNA has yielded a greater detection rate than conventional fecal occult blood testing. The aim of this study was to determine the sensitivity and specificity of this detection method for colorectal adenomas and carcinomas using ITGA4, SFRP2 and p16 promoter methylation., Methods: The methylation status of ITGA4, SFRP2 and p16 promoters in bisulfite-modified stool DNA was investigated in a blinded manner with methylation specific PCR (MSP) from 31 endoscopically diagnosed healthy controls, 25 patients with adenomas and 30 patients with CRC., Results: Methylated ITGA4, SFRP2 and p16 promoters were detected in 36.7%, 60.0%, and 40.0% of the CRC samples and in 16.0%, 44.0%, and 24.0% of the colorectal adenomas, respectively. The sensitivity of the combined study using the three markers for CRC and colorectal adenoma detection was 70.0% and 72.0%. The specificity of this method was 96.8%., Conclusion: Our results demonstrate that ITGA4, SFRP2 and p16 promoter methylation in stool samples had high sensitivity and specificity for the detection of colorectal adenomas and CRC. This newly developed screening may be a useful non-invasive alternative screening for CRC detection.

Background/aims: Recent studies implicated inflammation playing an important role in the occurrence and advancement of colorectal cancer. Colorectal adenoma as the representative precursor lesion of colorectal cancer has meaningful association with inflammation. Accordingly, the purpose of this study was to evaluate the association between serum C-reactive protein (CRP) levels and the risk of colorectal adenoma., Methods: This study was undertaken on 5,487 subjects (3,478 men and 2,009 women) who underwent colonoscopy at the Health Promotion Center in Kangbuk Samsung Hospital and Samsung Medical Center. The subjects were allocated into 3,505 normal control subjects and 1,982 patients with colorectal adenoma. The mean level of CRP was compared between the two groups, and the correlations with other variables were analyzed by multiple regression analysis. Also, the risk of colorectal adenoma according to CRP level and difference of CRP level according to the characteristics of adenomas were analyzed., Results: There was no significant difference in serum CRP level between normal and colorectal adenoma group. After adjusting for the clinically significant variables of colorectal adenoma, multiple logistic regression analysis of the risk of colorectal adenoma according to the CRP level (<1, 1-3, >3) and the CRP level according to characteristics of adenomas showed no significant difference., Conclusions: An inflammatory marker, CRP is not a risk factor for colorectal adenoma development.

Objectives: Nonpolypoid adenomas, which can be important precursors of colorectal cancers, are difficult to find during routine colonoscopy. The aim of this study was to evaluate the usefulness of routine chromoendoscopy in Korea, where the incidence of colorectal cancer is low compared with western countries., Methods: Colonoscopy with chromoendoscopy was performed in 74 consecutive patients (48 men, 26 women; mean age 53.0 yr). After a careful examination of the whole colon, a defined segment of the sigmoid colon and rectum (0-30 cm from the anal verge) was stained with 20 ml of 0.2% indigocarmine solution with a spraying catheter. Nonpolypoid lesions were classified as flat or depressed types. Biopsies were taken from all lesions detected before or after staining with indigocarmine., Results: Indications for colonoscopy included routine check-up (21 patients), diarrhea or loose stool (14 patients), abdominal pain (12 patients), constipation (7 patients), bleeding (6 patients), and others (14 patients). Before staining, 58 lesions were found in 30 patients (43.2%). Histology showed tubular adenoma in 41 lesions, hyperplastic or inflammatory changes in 14 lesions, adenocarcinoma in 2 lesions, and villous adenoma in 1 lesion. After indigocarmine staining for normal-looking distal 30 cm colorectal mucosa, 176 lesions were found in 46 patients (62.2%). Histologically, 158 lesions were hyperplastic or inflammatory in nature, and 17 lesions (from 11 patients) were tubular adenomas. There was one serrated adenoma. Eighteen adenomas seen only after spraying indigocarmine were 2.6 +/- 0.6 mm in diameter, and all of them were classified as flat adenomas. There was no depressed-type adenoma. No adenoma with high grade dysplasia, villous histology, or cancer was found after staining. Presence of macroscopic adenomatous lesions or carcinoma before staining could not predict the existence of adenoma after staining., Conclusions: In a large proportion of patients, flat or depressed adenomas could be found after spraying indigocarmine for normal-looking colorectal mucosa in Korea. The clinical significance of these diminutive adenomas that can be found only after spraying contrast agent needs to be further investigated.