Effects of RAD50 SNP, sodium intake, and H. pylori infection on gastric cancer survival in Korea.

BACKGROUND: Double-strand break repair protein (RAD50) gene plays important roles in genomic integrity, DNA double-strand break repair, cell cycle checkpoint activation, telomere maintenance, and meiotic recombination. The risk allele of RAD50 may negatively affect cancer by reducing the DNA repair capacity. Additionally, Sodium intake and Helicobacter pylori (H. pylori) infection are major risk factors for gastric cancer (GC). Our study investigated the association between polymorphisms in RAD50 gene and the risk of GC case-fatality. We evaluated whether the association differed with sodium intake or H. pylori infection. METHODS: We enrolled 490 patients from two hospitals between 2002 and 2006. Their survival or death was prospectively followed up until December 31, 2016, through a review of medical records and telephone surveys. The GC survival was assessed using the Cox proportional hazards regression analysis. RESULTS: In 319 GC cases, the total person-years were 1928.3, and the median survival years was 5.4 years. A total of 137 GC deaths were recorded. Our fully adjusted model showed that the GG type of RAD50 rs17772583 polymorphism is significantly associated with an increased risk of GC case-fatality (hazard ratio [HR] = 2.20, 95% confidence interval [CI] = 1.28-3.77) compared to that associated with the homozygous AA type. In the high sodium intake group, patients with the GG type of RAD50 rs17772583 showed a significantly higher GC case-fatality (HR = 8.61, 95% CI = 2.58-26.68) than that of patients with homozygous AA type. In the positive-H. pylori infection group, patients with GG-type RAD50 rs17772583 showed a significantly higher GC case-fatality (HR = 10.11, 95% CI = 2.81-36.35) than that of with AA homozygotes. CONCLUSIONS: Patients with GG-type RAD50 rs17772583, high sodium intake, or a positive-H. pylori infection are at a significantly increased risk of GC case-fatality compared to that associated with the absence of these risk factors.

Association of Dietary Antioxidant Vitamin Intake and Gastric Cancer Risk According to Smoking Status and Histological Subtypes of Gastric Cancer: A Case-Control Study in Korea.

Smoking is a risk factor for gastric cancer (GC) and causes oxidative stress. Antioxidant vitamins may protect against oxidative stress. This study aimed to determine the association between dietary antioxidant vitamin intake and GC risk according to smoking status and the histological subtype. This case-control study included 286 pairs of patients with GC and controls aged 20-79 years enrolled at two hospitals from 2002 to 2006, matched by age (± 2 years), sex, hospital, and participation period (± 1 years). Dietary information was collected using a quantitative food frequency questionnaire (FFQ). When stratified by smoking status, increased intake of vitamin C (OR = 0.38; 95% CI = 0.17-0.84 for highest vs. lowest; P for trend = 0.033) and folate (OR = 0.28; 95% CI = 0.12-0.64 for highest vs. lowest; P for trend = 0.003) decreased GC risk in nonsmokers. Vitamin C (P for interaction = 0.043) and folate (P for interaction =0.015) levels were significantly associated with smoking status. Similar results were observed in nonsmokers with diffuse and mixed types of GC, but not in those with intestinal type of GC. Therefore, we found an inverse association between higher intake of dietary vitamin C and folate with the risk of GC among nonsmokers. These protective associations were strong in nonsmokers with diffuse and mixed types of GC.

Clinical importance of weight gain and associated factors in patients with moderate to severe ulcerative colitis: results from the MOSAIK cohort in Korea.

BACKGROUND: Many patients with ulcerative colitis (UC) gain weight after treatment. However, the clinical significance of weight gain in these patients remains unclear. This study aimed to evaluate body weight changes after treatment in patients newly diagnosed with moderate-to-severe UC and their effects on patients' prognosis. METHODS: The change in weight between diagnosis and 1 year after treatment in 212 patients enrolled in the MOSAIK cohort (mean age, 40 years; males, 60%) was analyzed. Significant weight gain was defined as a weight increase of ≥ 5% from the baseline at 1 year. Factors associated with significant weight gain and the effect of significant weight gain on the risk of major adverse outcomes (clinical relapse, hospitalization, and new use of steroids or biologics) during a follow-up period of 20 months were evaluated. RESULTS: Mean weight gain at 1 year was 1.7 ± 4.2 kg. The proportion of overweight/obese patients increased by 9.0% from 37.9% to 46.9%. Thirty-two percent had significant weight gain; extensive colitis at diagnosis was the only factor associated with significant weight gain (odds ratio 6.5, 95% confidence interval 1.4-31.0, p = 0.006). In multivariable analysis, significant weight gain was not associated with the risk of major adverse outcomes. Weight loss symptoms at diagnosis were associated with an increased risk for new steroid use after 1 year. CONCLUSIONS: Approximately one-third of patients with moderate-to-severe UC had significant weight gain after 1 year of treatment. However, significant weight gain was not associated with the patient's prognosis.

The Associations of Dietary Intake of High Sodium and Low Zinc with Gastric Cancer Mortality: A Prospective Cohort Study in Korea.

Sodium and zinc display opposite effects on immune cells, such as regulatory T cells (Tregs) and T helper 17 cells (Th17), resulting in an altered immune response. Immune cells have a pivotal role in regulating tumor progression, which may affect gastric cancer (GC) mortality. Thus, this cohort study investigated the associations between the combination of sodium and zinc intake and GC mortality and whether these associations differ by histological type by following up deaths of GC cases in Korea. A total of 490 patients with GC were enrolled between 2002 and 2006. Survival or death was prospectively followed up until December 31, 2016. Finally, 300 patients with the two main histological types of GC were included; 99 GC deaths occurred during a median follow-up period of 7.1 years. Patients with high sodium and low zinc intake had a significantly higher GC mortality than those with low sodium and high zinc intake (hazard ratio [HR], 2.07; 95% confidence interval [CI], 1.09-3.93). However, no significant association was found between the histological types of GC. In conclusion, we found that high sodium and low zinc intake may worsen the survival rate of patients with GC.

Sex-dependent associations between MAP3K1 gene polymorphisms and soy products with the gastric cancer risk in Korea: a case-control study.

BACKGROUND/OBJECTIVES: The hormone-dependent effect of MAP3K1 gene polymorphisms may explain sex-specific differences in gastric cancer (GC) risk. Phytoestrogens have been shown to interact with this genetic factor. Here, we investigated the association between MAP3K1 gene polymorphisms and GC risk by sex and whether these associations differ depending on soy products intake. METHODS: Participants aged 20-79 years were recruited from two hospitals between December 2002 and September 2006. In all, 440 cases and 485 controls were recruited, among, 246 pairs of cases and controls, matched by sex, age (± 5 years), study admission period (± 1 years), and hospital, were included for the analysis. RESULTS: In dominant model, men with the A allele of rs252902 showed significantly increased GC risk (odd ratio; OR=2.19, 95% confidence interval; CI=1.31-3.64) compared to GG homozygotes. When stratified by intake of soy products, men with the A allele of rs252902 and low intake of soy products showed significantly higher GC risk (OR=3.29, 95% CI=1.55-6.78) than that in GG homozygotes. CONCLUSIONS: Men with the risk allele of MAP3K1 had a significantly increased GC risk compared to GG homozygotes; this trend was more pronounced in those with low intake of soy products.

Second Victim Experience and Perception Discordance of the Colonoscopic Perforation.

BACKGROUND: Perforation is the most serious adverse event of colonoscopy, but rarely considered from the view of colonoscopists' second victim experience and perception discordance between colonoscopists and patients. AIMS: We aimed to evaluate colonoscopists' second victim experience and the perception discordance between colonoscopists and patients for the colonoscopic perforation. METHODS: A survey for colonoscopic perforation was performed for the colonoscopists and outpatients who visited the university hospital between February 1, 2020, and April 30, 2020. The questionnaire included questions regarding colonoscopists' satisfaction for the intervention strategies offered to patients and patient-colonoscopist perception on colonoscopic perforation. A modified Korean version of the "Second Victim Experience and Support Tool (K-SVEST)" was used to assess the second victim experiences and supportive resources for the colonoscopists. RESULTS: Survey results from 160 colonoscopists and 165 patients were analyzed. The colonoscopists' satisfaction scores were higher for strategies related to sufficient explanation, empathy, courteous listening, and monetary compensation. The scores of the K-SVEST for the second victim experience were highest in psychological distress, followed by loss of professional self-efficacy, colleague support, physical distress, non-work-related support, institutional support, and turnover intentions/absenteeism. Significant patient-colonoscopist discordance was noted for the same colonoscopic perforation scenario on the judgment of medical error, health professionals' apology, monetary compensation, and criminal penalties for the colonoscopists. CONCLUSIONS: Colonoscopists can suffer emotionally and physically from the second victim experience after colonoscopic perforation. In addition, the significant patient-colonoscopist discordance should be considered to make a better communication for the colonoscopic perforation.

Early course of newly diagnosed moderate-to-severe ulcerative colitis in Korea: Results from a hospital-based inception cohort study (MOSAIK).

BACKGROUND AND AIM: No inception cohort study has ever evaluated the early course of moderate-to-severe ulcerative colitis (UC) within 1 year of diagnosis in the non-Caucasian population. We aimed to investigate the early clinical course of moderate-to-severe UC patients in terms of remission, relapse, UC-related hospitalizations, colectomy, mortality, and overall use of medications. METHODS: In the MOSAIK inception cohort, which is an ongoing multicenter, prospective, hospital-based, observational cohort, 354 patients with moderate-to-severe UC were followed up for 1 year. Main outcomes of UC and predictive factors for medication use over the course of 1 year were evaluated. RESULT: Among 354 patients, 276 (78.0%) patients were followed up for 1 year. The rates of remission, relapse, UC-related hospitalizations, and proximal disease extension were 95.3%, 39.6%, 15.2%, and 12.3%, respectively. Systemic corticosteroids, thiopurines, and biologics were administered to 61.2%, 30.4%, and 10.5% of patients, respectively, throughout 1 year. One year after, 58.2% patients experienced remission or mild endoscopic activity. Overall disease courses did not show much difference according to moderate or severe disease activity at baseline. In addition, no colectomy and mortality were observed for 1 year. Predictive factors for medication use included disease severity, disease extent, endoscopic severity, and presence of periappendiceal inflammation at baseline for corticosteroid, disease extent and initial corticosteroid use for thiopurine, and only initial corticosteroid use for biologics. CONCLUSION: Korean patients with moderate-to-severe UC may have more favorable early outcomes than Western patients. However, outcomes of them need to be further looked into for a longer time.

Efficacy and safety of biosimilar CT-P13 compared with originator infliximab in patients with active Crohn's disease: an international, randomised, double-blind, phase 3 non-inferiority study.

BACKGROUND: The infliximab biosimilar CT-P13 was approved for use in Crohn's disease after clinical comparison with originator infliximab in ankylosing spondylitis and rheumatoid arthritis; however, concerns about such indication extrapolation have been expressed. This study investigated whether CT-P13 is non-inferior to infliximab in patients with Crohn's disease who were naive to biological therapy. METHODS: In this randomised, multicentre, double-blind, phase 3 non-inferiority study, we enrolled patients with active Crohn's disease who had not responded to, or were intolerant to, non-biological treatments. Patients were randomly assigned (1:1:1:1) to receive CT-P13 then CT-P13, CT-P13 then infliximab, infliximab then infliximab, or infliximab then CT-P13, with switching occurring at week 30. Patients received 5 mg/kg CT-P13 or infliximab at weeks 0, 2, 6, and then every 8 weeks up to week 54. The primary endpoint was the proportion of patients with a decrease of 70 points or more in Crohn's Disease Activity Index (CDAI) from baseline to week 6. A non-inferiority margin of -20% was set (CT-P13 was non-inferior to infliximab if the lower limit of the two-sided 95% CI for the treatment difference was greater than -20). This trial is registered with ClinicalTrials.gov, number NCT02096861, and is completed. FINDINGS: Between Aug 20, 2014, and Feb 15, 2017, 308 patients were assessed for eligibility, and 220 patients were enrolled: 111 were randomly assigned to initiate CT-P13 (56 to the CT-P13-CT-P13 group and 55 to the CT-P13-infliximab group) and 109 to initiate infliximab (54 to the infliximab-infliximab group and 55 to the infliximab-CT-P13 group). CDAI-70 response rates at week 6 were similar for CT-P13 (77 [69·4%, 95% CI 59·9 to 77·8] of 111) and infliximab (81 [74·3%, 95% CI 65·1 to 82·2] of 109; difference -4·9% [95% CI -16·9 to 7·3]), thereby establishing non-inferiority. Over the total study period, 147 (67%) patients experienced at least one treatment-emergent adverse event (36 [64%] in the CT-P13-CT-P13 group, 34 [62%] in the CT-P13-infliximab group, 37 [69%] in the infliximab-infliximab group, and 40 [73%] in the infliximab-CT-P13 group). INTERPRETATION: This study showed non-inferiority of CT-P13 to infliximab in patients with active Crohn's disease. Biosimilar CT-P13 could be a new option for the treatment of active Crohn's disease. FUNDING: Celltrion, Pfizer.

Cap-Assisted Chromoendoscopy Using a Mounted Cap Versus Standard Colonoscopy for Adenoma Detection.

OBJECTIVES: Some neoplastic lesions remain undetected on colonoscopy. To date, no studies have investigated whether combining cap-assisted colonoscopy with chromoendoscopy increases the adenoma detection rate (ADR). This study aimed to compare cap-assisted chromoendoscopy (CAP/CHROMO) with standard colonoscopy (SC) with respect to their efficacy in detecting adenomas. METHODS: This prospective, multicenter, randomized controlled trial included asymptomatic subjects aged 45-75 years who underwent colonoscopy for the first time at 14 university hospitals. Subjects were randomized to either the CAP/CHROMO group (with 0.09% indigo carmine spraying using a cap-mounted catheter at the tip of the colonoscope) or the SC group. All polyps were resected, but only histologically confirmed neoplastic lesions were considered for analysis. The primary outcome was ADR, defined as the proportion of subjects with at least 1 adenoma. RESULTS: A total of 1,905 subjects were randomized to the CAP/CHROMO (n = 948) or SC (n = 957) group at 14 centers. Subjects' demographic characteristics were similar between both groups. The CAP/CHROMO group had significantly higher ADR than the SC group (54.4% vs 44.9%, P < 0.001). Significantly, more subjects with at least 1 proximal colon adenoma were identified by CAP/CHROMO (38.6%) than by SC (31.2%) (P = 0.001). The proximal serrated polyp detection rate by CAP/CHROMO was significantly higher in the female subgroup vs SC. However, advanced ADR was not different between the CAP/CHROMO and SC groups (9.3% vs 7.6%, P = 0.180). DISCUSSION: CAP/CHROMO markedly improved the ADR and enhanced the detection of proximal adenoma. CAP/CHROMO is feasible for routine application and will allow for a more effective surveillance program.

Novel sulfate tablet PBK-1701TC versus oral sulfate solution for colon cleansing: A randomized phase 3 trial.

BACKGROUND AND AIM: PBK-1701TC is a novel sulfate tablet-based that contains 320 mg of simethicone and delivers 90% of the salt and water delivered by oral sulfate solution (OSS) preparation. This study evaluated the efficacy, safety, and tolerability of PBK-1701TC compared with OSS in bowel preparation for colonoscopy. METHODS: This randomized, multicenter, phase 3 non-inferiority trial included adults aged 19 years or older with a body mass index of 19-30 kg/m2 undergoing colonoscopy at five university hospitals in Korea. The primary efficacy endpoint was successful bowel-cleansing rate, defined as Harefield Cleansing Scale grade A or B as evaluated by blinded central readers. Secondary endpoints included the presence of residual air bubbles. Adverse events and laboratory evaluations were monitored to assess safety. Tolerability was assessed via participant interview. RESULTS: Overall, 235 participants were randomized, and 224 were included in the per-protocol analysis (PBK, 112; OSS, 112). Successful bowel cleansing was achieved for 95.5% (107/112) in the PBK group, which was non-inferior to the OSS group (98.2%, 110/112) with a difference of -2.7% (one sided 97.5% confidence limit, -8.1%). The participants in the PBK group had fewer intraluminal bubbles (0.9% vs 81.3%, P < 0.001) and reported a lower incidence of nausea and vomiting, with better acceptance, taste, and willingness to repeat the regimen than those in the OSS group (all P < 0.05). CONCLUSION: The novel sulfate tablet, PBK-1701TC, was non-inferior to OSS with respect to bowel-cleansing efficacy and exhibited better safety and tolerability in adults undergoing colonoscopy.

Evaluation of gastric microbiome and metagenomic function in patients with intestinal metaplasia using 16S rRNA gene sequencing.

BACKGROUND: Despite recent advances in studies on the gastric microbiome, the role of the non-Helicobacter pylori gastric microbiome in gastric carcinogenesis remains unclear. We evaluated the characteristics of the gastric microbiome and metagenomic functions in patients with IM. METHODS: Participants were classified into six groups according to disease status (chronic superficial gastritis [CSG], intestinal metaplasia [IM], and cancer) and H. pylori- infection status (H. pylori-positive and H. pylori-negative). The gastric microbiome was analyzed in mucosal tissues at the gastric antrum by 16S rRNA gene sequencing. Moreover, we assessed the metagenome including the type IV secretion system (T4SS) gene, as T4SS proteins are essential for transferring CagA from H. pylori- into the human gastric epithelium. RESULTS: Among the 138 included patients, 48, 9, 23, 14, 12, and 32 were classified into the H. pylori-negative CSG, H. pylori-negative IM, H. pylori-negative cancer, H. pylori-positive CSG, H. pylori-positive IM, and H. pylori-positive cancer groups, respectively. Cyanobacteria were predominant in the H. pylori-negative CSG group compared to in the H. pylori-negative IM and H. pylori-negative cancer groups (H. pylori-negative CSG vs H. pylori-negative IM vs H. pylori-negative cancer: 14.0% vs 4.2% vs 0.04%, P < 0.001). In contrast, Rhizobiales were commonly observed in the H. pylori-negative IM group (H. pylori-negative CSG vs H. pylori-negative IM vs H. pylori-negative cancer: 1.9% vs 15.4% vs 2.8%, P < 0.001). The relative abundance of Rhizobiales increased as H. pylori-infected stomachs progressed from gastritis to IM. In the H. pylori-negative IM group, genes encoding T4SS were prevalent among the metagenome. Additionally, after H. pylori- eradication therapy, the gastric microbiome was similar to the microbiome observed after spontaneous clearance of H. pylori-. CONCLUSIONS: The relative abundance of Rhizobiales was higher in patients with H. pylori-negative IM than in those with H. pylori-negative CSG or cancer. Additionally, T4SS genes were highly observed in the metagenome of patients with IM. Highly abundant T4SS proteins in these patients may promote gastric carcinogenesis.

A Randomized Controlled Trial Comparing Colonoscopic Enema With Additional Oral Preparation as a Salvage for Inadequate Bowel Cleansing Before Colonoscopy.

GOALS: The goal of this study was to evaluate the noninferiority of colonoscopic enema to additional oral preparation in salvage bowel cleansing for inadequate preparation for a morning colonoscopy. BACKGROUND: Colonoscopic enema, administering additional cathartics into the right colon through the colonoscope accessory channel, is suggested to rescue poor bowel preparation for a colonoscopy but lacking comparative study. STUDY: In this prospective, randomized, actively-controlled, parallel group, noninferiority trial, consecutive outpatients and health checkup recipients aged from 19 to 70 years with inappropriate bowel preparation during an elective colonoscopy were enrolled to receive either a colonoscopic enema of 1 L polyethylene glycol (PEG) (enema group) or additional oral intake of 2 L PEG (oral group). The primary endpoint was the proportion of adequate bowel preparation evaluated using the Boston Bowel Preparation Scale. RESULTS: Overall, 131 participants were randomized. Adequate bowel preparation was achieved in 53% (35/66) of the enema group, which was significantly inferior to the oral group (81.5%; 53/67) with a difference of -28.5% (95% confidence interval, -44.1, -12.9; P=0.001). The largest difference in the proportion of adequate bowel preparation was observed in the right colon (57.8% in the enema group vs. 86.9% in the oral group; P<0.001), followed by the transverse colon (85.9% vs. 98.4%; P=0.017) and the left colon (90.6% vs. 96.7%; P=0.274). CONCLUSIONS: The colonoscopic enema of 1 L PEG was inferior to the additional oral ingestion of 2 L PEG regarding efficacy as a salvage bowel preparation in adults with inadequate bowel cleansing for colonoscopy.

Long-term efficacy and safety of CT-P13, a biosimilar of infliximab, in patients with inflammatory bowel disease: A retrospective multicenter study.

BACKGROUND AND AIM: A biosimilar of infliximab, CT-P13 (Remsima®) has the potential to reduce treatment costs and enhance access to biological therapy for inflammatory bowel disease (IBD) patients. However, long-term clinical data on its use for IBD treatment are currently sparse. We aimed to investigate the long-term efficacy and safety of CT-P13 therapy in a large, real-life IBD cohort. METHODS: A total of 368 IBD patients (227 with Crohn's disease [CD] and 141 with ulcerative colitis [UC]) treated with CT-P13 at 16 referral hospitals in Korea between July 2012 and December 2017 were retrospectively analyzed. RESULTS: The cumulative retention rates at years 1, 3, and 5 were 86.1%, 68.5%, and 58.7% and 69.7%, 46.0%, and 26.7% in anti-tumor necrosis factor (TNF)-naïve CD and UC patients, respectively. The clinical response and remission rates at week 14 and at years 1, 3, and 5 were 94.3%, 92.7%, 76.8%, and 17.6% and 78.6%, 82.4%, 72.2%, and 17.6% in anti-TNF-naïve CD and 85.6%, 80.0%, 55.2%, and 6.7% and 42.6%, 59.8%, 44.2%, and 6.7% in anti-TNF-naïve UC patients, respectively. Among patients who switched from the biologic originator to CT-P13, the cumulative retention rates at years 1, 3, and 5 were 88.5%, 66.1%, and 44.8% in CD, and 73.9%, 42.5%, and 42.5% in UC patients, respectively. Significant improvements in disease activity scores were accompanied by marked reductions in inflammatory marker levels, and no unexpected adverse events including death or malignancy occurred during the study period. CONCLUSIONS: Long-term treatment with CT-P13 is effective in inducing and maintaining disease improvement and is well-tolerated in patients with IBD. CT-P13 may be a promising treatment option for IBD.

Comparative efficacy of cold polypectomy techniques for diminutive colorectal polyps: a systematic review and network meta-analysis.

BACKGROUND: Although cold polypectomy techniques are preferred over polypectomy with electrocautery in the management of diminutive polyps, comprehensive comparisons among various cold polypectomy techniques have not yet been fully performed. METHODS: We searched for all relevant randomized controlled trials published up until October 2016 examining the efficacy of cold polypectomy techniques for diminutive polyps. Cold polypectomy techniques were classified as cold forceps polypectomy (CFP), jumbo forceps polypectomy (JFP), traditional cold snare polypectomy (CSP), and dedicated CSP, according to the type of device. A network meta-analysis was performed to calculate the direct and indirect estimates of efficacy among the cold polypectomy techniques. RESULTS: Seven studies with 703 patients and 968 polyps were included in the meta-analysis. Regarding comparative efficacy for complete histological eradication, there was no inconsistency in the network (Cochran's Q test, df = 4, P = 0.22; I 2 = 30%). In terms of complete histological eradication, both dedicated and traditional CSP were superior to CFP (odds ratio [OR] [95% confidence interval [CI]] 4.31 [1.92-9.66] and 2.45 [1.30-4.63], respectively); dedicated CSP was superior to traditional CSP (OR [95% CI] 1.76 [1.07-2.89]); and there was no difference between JFP versus CFP (OR [95% CI] 1.36 [0.40-4.61]). Regarding tissue retrieval rate, there was no difference between dedicated versus traditional CSP (OR [95% CI] 1.03 [0.44-2.38]). The procedure time for CSP was comparable to that of CFP. CONCLUSIONS: Dedicated CSP was shown to be superior to other cold polypectomy techniques in terms of complete histological eradication. Cold polypectomy using a dedicated snare can be recommended for the removal of diminutive colorectal polyps.

Metformin use and the risk of colorectal adenoma: A systematic review and meta-analysis.

BACKGROUND AND AIM: Although it is known that metformin can reduce risk of colorectal cancer, it is unclear whether it protects against colorectal adenoma. METHODS: This study conducted a systematic literature search on MEDLINE, EMBASE, and the Cochrane Library using the primary keywords "colorectal," "colon," "rectal," "rectum," "adenoma," "polyp," "neoplasia," "neoplasm," "metformin," and "diabetes." Studies were included if they evaluated the association between metformin use and colorectal adenoma and reported odds ratios (ORs) or provided data from which these could be estimated. RESULTS: Ten studies and a total of 8726 patients were evaluated. Across all studies, a median of 32.1% (range: 15.2-53.0%) of patients taking metformin also had adenoma; a median of 43.5% (range: 20.5-59.6%) of those not taking metformin had adenoma. In our meta-analysis, metformin use reduced the risk of adenoma (pooled OR = 0.76, 95% confidence interval [CI] = 0.63-0.92, I2  = 60%). Upon subgroup analyses, metformin use tended to reduce risk of adenoma in a high-risk population consisting of patients with a history of colorectal neoplasia (CRN) (pooled OR = 0.61, 95% CI = 0.34-1.10, I2  = 79%). In addition, metformin reduced the risk of adenoma in a high-risk population consisting of patients with diabetes mellitus (pooled OR = 0.75, 95% CI = 0.62-0.91, I2  = 57%). CONCLUSION: Metformin use seemed to be associated with a reduced risk of colorectal adenoma, especially in high-risk populations consisting of patients with diabetes mellitus or a history of CRN, although statistical power was not achieved in patients with a history of CRN.

Role of second-look endoscopy and prophylactic hemostasis after gastric endoscopic submucosal dissection: A systematic review and meta-analysis.

BACKGROUND: Although several studies have shown that second-look endoscopy does not affect the incidence of bleeding after gastric endoscopic submucosal dissection (ESD), the potential roles of second-look endoscopy have not been fully evaluated. This study aimed to determine the role of second-look endoscopy after ESD through a systematic review and meta-analysis. METHODS: This study conducted a systematic literature search of MEDLINE, EMBASE, and the Cochrane Library through March 2016 using the keywords "second-look," "prophylactic hemostasis," "prophylactic haemostasis," "prevention," "prophylaxis," and "endoscopic submucosal dissection." Studies were included if they evaluated the incidence of post-ESD bleeding according to second-look endoscopy or prophylactic hemostasis during second-look endoscopy. RESULTS: Four randomized controlled trials on post-ESD bleeding between second-look endoscopy and no second-look endoscopy and 12 non-randomized studies with a cohort design on post-ESD bleeding were included. On meta-analysis, second-look endoscopy did not affect delayed post-ESD bleeding (odds ratio [95% confidence interval] = 1.27 [0.80-2.00], I2  = 0%). During second-look endoscopy, patients who were considered as high-risk for post-ESD bleeding underwent prophylactic hemostasis. Delayed post-ESD bleeding was more common in patients who were treated with hemostasis during second-look endoscopy compared with those who were not (odds ratio [95% confidence interval] = 3.40 [1.87-6.18], I2  = 62%). In patients who underwent prophylactic hemostasis, the number needed to prolong a hospitalization period to avoid one additional post-ESD bleeding after discharge was 25. CONCLUSION: Second-look endoscopy after ESD could not reduce the risk of delayed post-ESD bleeding. Delayed post-ESD bleeding was more common in patients who underwent prophylactic hemostasis than in those who did not.

Comparison of Efficacy of Prophylactic Endoscopic Therapies for Postpolypectomy Bleeding in the Colorectum: A Systematic Review and Network Meta-Analysis.

OBJECTIVES: Although various endoscopic therapies have been suggested for preventing bleeding after colorectal polypectomy, the optimal therapy has yet to be fully clarified. We assessed the comparative efficacy of prophylactic therapies for postpolypectomy bleeding through a network meta-analysis combining direct and indirect comparisons. METHODS: We searched for all relevant randomized controlled trials published up until January 2016 examining the effects of prophylactic therapy for bleeding after colorectal polypectomy. The types of prophylactic therapy were classified as mechanical therapy, epinephrine-saline injection therapy, coagulation therapy, combined therapy, or no prophylactic therapy. Combined therapy was defined as a combination of two or more types of therapy including mechanical therapy, epinephrine-saline injection therapy, and coagulation therapy. We performed a Bayesian network meta-analysis for all prophylactic therapies. RESULTS: Fifteen studies with 3,462 patients were included in the meta-analysis. Compared with no prophylactic therapy, both epinephrine-saline injection and mechanical therapy showed superiority for preventing early postpolypectomy bleeding with a moderate quality of evidence (injection therapy, risk ratio (RR; 95% credible interval (CrI))=0.32 (0.11-0.67); mechanical therapy, RR (95% CrI)=0.13 (0.03-0.37)). Combined therapy did not show a statistically significant difference for decreasing the risk of early bleeding compared with injection or mechanical therapies, respectively (combined vs. injection therapy: RR (95% CrI)=0.35 (0.10-1.00); combined vs. mechanical therapy: RR (95% CrI)=0.88 (0.23-3.00)). In cases of delayed bleeding, no type of prophylactic therapy decreased the risk of bleeding compared with no prophylactic therapy. CONCLUSIONS: Either mechanical therapy or injection therapy reduced the risk of early postpolypectomy bleeding. As for delayed bleeding, none of the prophylactic therapies was associated with a lower risk of bleeding compared with no prophylactic therapy.

Comparison of adenoma detection rate and adenoma per colonoscopy as a quality indicator of colonoscopy.

BACKGROUND: Although adenoma detection rate (ADR) has been proposed as a quality indicator of colonoscopies, adenomas per colonoscopy (APC) is a promising alternative to ADR, as it reflects inspection over the entire length of the colon. This study investigated the correlation between ADR and APC, and compared the efficacy of ADR and APC based on the correlation of each with the advanced adenoma detection rate (AADR). STUDY: Two prospectively collected databases, including the 1142 subjects who underwent screening colonoscopies by 28 colonoscopists, were retrospectively reviewed. AADR1 were definded as the proportion of participants having advanced neoplasms, and AADR2 were definded as the proportion of participants having advanced neoplasms or three or more adenomas. Pearson correlation and Steiger's z-test was used to evaluate the relationship between ADR-APC, ADR-AADR and APC-AADR. RESULTS: The ADRs ranged from 16.67 to 66.67% (mean, 37.29%) and APCs ranged from 0.22 to 1.28 (mean, 0.65). The ADR and APC showed a significant correlation (R = 0.82; p < 0.001). The screening ADR was significantly correlated with AADR1/AADR2 (R = 0.60; p = 0.001 and R = 0.64; p < 0.001, respectively). APC was also significantly correlated with AADR1/AADR2 (R = 0.65; p < 0.001 and R = 0.77; p < 0.001, respectively). The correlation coefficient for APC-AADR2 was higher than ADR-AADR2 (0.77 versus 0.64, p = 0.04). CONCLUSIONS: Colonoscopists' ADRs and APC were significantly correlated. Moreover, as the correlation coefficient for AADR was higher with APC than it was with ADR, APC might be a better quality indicator of colonoscopy than ADR.

Does the intestinal microbial community of Korean Crohn's disease patients differ from that of western patients?

BACKGROUND: Intestinal microbiota play an important role in maintaining the homeostasis of the host immune system. To analyze the alteration of the intestinal microbial community structure in Korean Crohn's disease (CD) patients, we performed a comparative metagenomic analysis between healthy people and CD patients using fecal samples and mucosal tissues of ileocecal valve. METHODS: 16S rRNA genes from fecal samples or mucosal tissues of 35 CD patients and 15 healthy controls (HC) were amplified using a universal primer set and sequenced with GS FLX Titanium. The microbial composition and diversity of each sample were analyzed with the mothur pipeline, and the association between microbial community and clinical characteristics of the patients were investigated. RESULTS: The contribution of bacterial groups to the intestinal microbial composition differed between CD and HC, especially in fecal samples. Global structure and individual bacterial abundance of intestinal microbial community were different between feces and ileocecal tissues in HC. In CD patients with active stage, relative abundances of Gammaproteobacteria and Fusobacteria were higher in both fecal and mucosal tissue samples. Moreover, the intestinal microbial community structure was altered by anti-tumor necrosis factor (anti-TNF) treatment. CONCLUSIONS: Our 16S rRNA sequence data demonstrate intestinal dysbiosis at the community level in Korean CD patients, which is similar to alterations of the intestinal microbial community seen in the western counterparts. Clinical disease activity and anti-TNF treatment might affect the intestinal microbial community structure in CD patients.

Statin use and the risk of colorectal adenoma: A meta-analysis.

BACKGROUND: Although statin use has been reported to reduce the risk of colorectal cancer beyond its cholesterol-lowering effects, the benefit of statins against colorectal adenoma has not been fully clarified. We aimed to investigate the association between statin use and the risk of colorectal adenoma. METHODS: We conducted a systematic literature search on MEDLINE, EMBASE, and the Cochrane Library using the primary keywords "adenoma," "polyp," "colorectal," "colon," "rectal," "rectum," "neoplasia," "neoplasm," "statin," "3-hydroxy-3-methylglutaryl-coenzyme A," and "HMG-CoA." Studies were included if they evaluated the association between statin use and adenoma and reported relative risks (RRs) or odds ratios or provided data for estimation. Pooled estimates were calculated using the random-effects model. RESULTS: Six studies including 13 239 patients were analyzed. The median proportion of patients with any adenoma was 29.7% (range, 20.9-38.4%) in patients taking statins and 31.2% (range, 19.6-63.4%) in patients not taking statins across included studies. The median proportion of patients with advanced adenoma in those taking statins was 7.7% (range, 3.1-27.2%), whereas that in patients not taking statins was 11.3% (range, 3.5-32.4%). On meta-analysis, statin use did not significantly affect the risk of any adenoma (pooled RR = 0.901; 95% confidence interval [CI], 0.735-1.104); however, it was associated with a lower risk of advanced adenoma (pooled RR = 0.833; 95% CI, 0.750-0.925). CONCLUSIONS: Statin use seems to be associated with a reduced risk of advanced adenoma, but not any adenoma. Statins may prevent neoplastic progression of adenomas rather than the development of adenomas.