Serum 25-Hydroxyvitamin D Levels and Risk of Colorectal Cancer: An Age-Stratified Analysis.

BACKGROUND & AIMS: The role of circulating 25-hydroxyvitamin D (25(OH)D) in the prevention of early-onset colorectal cancer (CRC) in young adults aged <50 years is uncertain. We evaluated the age-stratified associations (<50 vs ≥50 years) between circulating 25(OH)D levels and the risk of CRC in a large sample of Korean adults. METHODS: Our cohort study included 236,382 participants (mean age, 38.0 [standard deviation, 9.0] years) who underwent a comprehensive health examination, including measurement of serum 25(OH)D levels. Serum 25(OH)D levels were categorized as <10, 10 to 20, and ≥20 ng/mL. CRC, along with the histologic subtype, site, and invasiveness, was ascertained through linkage with the national cancer registry. Cox proportional hazard models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for incident CRC according to the serum 25(OH)D status, with adjustment for potential confounders. RESULTS: During the 1,393,741 person-years of follow-up (median, 6.5 years; interquartile range, 4.5-7.5 years), 341 participants developed CRC (incidence rate, 19.2 per 105 person-years). Among young individuals aged <50 years, serum 25(OH)D levels were inversely associated with the risk of incident CRC with HRs (95% CIs) of 0.61 (0.43-0.86) and 0.41 (0.27-0.63) for 25(OH)D 10 to 19 ng/mL and ≥20 ng/mL, respectively, with respect to the reference (<10 ng/mL) (P for trend <.001, time-dependent model). Significant associations were evident for adenocarcinoma, colon cancer, and invasive cancers. For those aged ≥50 years, associations were similar, although slightly attenuated compared with younger individuals. CONCLUSIONS: Serum 25(OH)D levels may have beneficial associations with the risk of developing CRC for both early-onset and late-onset disease.

Deep learning model using stool pictures for predicting endoscopic mucosal inflammation in patients with ulcerative colitis.

OBJECTIVES: Stool characteristics may change depending on the endoscopic activity of ulcerative colitis (UC). We developed a deep learning model using stool photos of patients with UC (DLSUC) to predict endoscopic mucosal inflammation. METHODS: This was a prospective multicenter study conducted in six tertiary referral hospitals. Patients scheduled to undergo endoscopy for mucosal inflammation monitoring were asked to take photos of their stool using smartphones within 1 week before the day of endoscopy. DLSUC was developed using 2161 stool pictures from 306 patients and tested on 1047 stool images from 126 patients. The ulcerative colitis endoscopic index of severity (UCEIS) was used to define endoscopic activity. The performance of DLSUC in endoscopic activity prediction was compared with that of fecal calprotectin (Fcal). RESULTS: The area under the receiver operating characteristic curve (AUC) of DLSUC for predicting endoscopic activity was 0.801 (95% confidence interval [CI] 0.717-0.873), which was not statistically different from the AUC of Fcal (0.837 [95% CI, 0.767-0.899, DeLong's P=0.458]). When rectal sparing cases (23/126, 18.2%) were excluded, the AUC of DLSUC increased to 0.849 (95% CI, 0.760-0.919). The accuracy, sensitivity, and specificity of DLSUC in predicting endoscopic activity were 0.746, 0.662, and 0.877 in all patients and 0.845, 0.745, and 0.958 in patients without rectal sparing, respectively. Active patients classified by DLSUC were more likely to experience disease relapse during a median 8-month follow-up (log-rank test, P=0.002). CONCLUSIONS: DLSUC demonstrated a good discriminating power similar to that of Fcal in predicting endoscopic activity with improved accuracy in patients without rectal sparing. This study implies that stool photos are a useful monitoring tool for typical UC.

Metabolic-associated fatty liver disease is associated with colorectal adenomas in young and older Korean adults.

BACKGROUND AND AIMS: Given that the majority of colorectal cancers (CRCs) develop from high-risk adenomas, identifying risk factors for high-risk adenomas is important. The relationship between metabolic dysfunction-associated fatty liver disease (MAFLD) and the risk of colorectal adenoma in young adults remains unclear. We aimed to evaluate this relationship in adults <50 (younger) and ≥50 (older) years of age. METHODS: This cross-sectional study included 184 792 Korean adults (80% <50 years of age) who all underwent liver ultrasound and colonoscopy. Participants were grouped into those with and without MAFLD and classified by adenoma presence into no adenoma, low-risk adenoma, or high-risk adenoma (defined as ≥3 adenomas, any ≥10 mm, or adenoma with high-grade dysplasia/villous features). RESULTS: The prevalence of low- and high-risk adenomas among young and older adults was 9.6% and 0.8% and 22.3% and 4.8%, respectively. MAFLD was associated with an increased prevalence of low- and high-risk adenomas in young and older adults. Young adults with MAFLD had a 1.30 (95% CIs 1.26-1.35) and 1.40 (1.23-1.59) times higher prevalence of low- and high-risk adenomas, respectively, compared to those without MAFLD. These associations were consistent even in lean adults (BMI < 23 kg/m2 ) and those without a family history of CRC. CONCLUSIONS: MAFLD is associated with an increased prevalence of low- and high-risk adenomas in Korean adults, regardless of age or obesity status. Whether reducing metabolic risk factors, such as MAFLD, reduces the risk of precancerous lesions and ultimately reduces the risk of early-onset CRC requires further investigation.

Comparison of the Pharmacokinetics of CT-P13 Between Crohn's Disease and Ulcerative Colitis.

BACKGROUND: We aimed to compare trough infliximab levels and the development of antidrug antibody (ADA) for 1 year between Crohn's disease (CD) and ulcerative colitis (UC) patients who were biologic-naive, and to evaluate their impact on clinical outcomes. METHODS: This was a prospective, multicenter, observational study. Biologic-naive patients with moderate to severe CD or UC who started CT-P13, an infliximab biosimilar, therapy were enrolled. Trough drug and ADA levels were measured periodically for 1 year after CT-P13 initiation. RESULTS: A total of 267 patients who received CT-P13 treatment were included (CD 168, UC 99). The rates of clinical remission (72% vs. 32.3%, P <0.001) at week 54 were significantly higher in CD than in UC. The median trough drug level (µg/mL) was significantly higher in CD than in UC up to week 14 (week 2, 18.7 vs. 14.7, P <0.001; week 6, 12.5 vs. 8.6, P <0.001; week 14, 3.4 vs. 2.5, P =0.001). The median ADA level (AU/mL) was significantly lower in CD than in UC at week 2 (6.3 vs. 6.5, P =0.046), week 30 (7.9 vs. 11.8, P =0.007), and week 54 (9.3 vs. 12.3, P =0.032). Development of ADA at week 2 [adjusted odds ratio (aOR)=0.15, P =0.026], initial C-reactive protein level (aOR=0.87, P =0.032), and CD over UC (aOR=1.92, P <0.001) were independent predictors of clinical remission at week 54. CONCLUSION: Infliximab shows more favorable pharmacokinetics, including high drug trough and low ADA levels, in CD than in UC, which might result in better clinical outcomes for 1-year infliximab treatment in CD patients.

Enrichment of Activated Fibroblasts as a Potential Biomarker for a Non-Durable Response to Anti-Tumor Necrosis Factor Therapy in Patients with Crohn's Disease.

We investigated whether the response to anti-tumor necrosis factor (anti-TNF) treatment varied according to inflammatory tissue characteristics in Crohn's disease (CD). Bulk RNA sequencing (RNA-seq) data were obtained from inflamed and non-inflamed tissues from 170 patients with CD. The samples were clustered based on gene expression profiles using principal coordinate analysis (PCA). Cellular heterogeneity was inferred using CiberSortx, with bulk RNA-seq data. The PCA results displayed two clusters of CD-inflamed samples: one close to (Inflamed_1) and the other far away (Inflamed_2) from the non-inflamed samples. Inflamed_1 was rich in anti-TNF durable responders (DRs), and Inflamed_2 was enriched in non-durable responders (NDRs). The CiberSortx results showed that the cell fraction of activated fibroblasts was six times higher in Inflamed_2 than in Inflamed_1. Validation with public gene expression datasets (GSE16879) revealed that the activated fibroblasts were enriched in NDRs over Next, we used DRs by 1.9 times pre-treatment and 7.5 times after treatment. Fibroblast activation protein (FAP) was overexpressed in the Inflamed_2 and was also overexpressed in the NDRs in both the RISK and GSE16879 datasets. The activation of fibroblasts may play a role in resistance to anti-TNF therapy. Characterizing fibroblasts in inflamed tissues at diagnosis may help to identify patients who are likely to respond to anti-TNF therapy.

Risk of post-polypectomy bleeding after endoscopic mucosal resection in patients receiving antiplatelet medication: comparison between the continue and hold groups.

BACKGROUND: Current guidelines recommend continuing aspirin and discontinuing clopidogrel for colon polypectomy, but evidence for endoscopic mucosal resection (EMR) is insufficient. We aimed to assess post-polypectomy bleeding (PPB) in patients receiving antiplatelet agents and underwent EMR for various polyp sizes. METHODS: A single-center, prospective observational study was performed. Patients who underwent at least one EMR for polypectomy and those who received aspirin or clopidogrel were included. We compared PPB between the antiplatelet hold group (stopped antiplatelet therapy at least 5 days before the procedure) and continue group (antiplatelet therapy was maintained or stopped within 5 days before the procedure). RESULTS: Among patients who underwent EMR, 305 took aspirin (hold group 257, continue group 48) and 77 took clopidogrel (hold group 66, continue group 11). The mean number of polyps was four, and the mean size was 8.6 mm. There was no difference in the major PPB rate between the hold and continue groups among aspirin users (2.0% vs. 4.2%, P = 0.30), but it was significantly higher in the continue group than in the hold group among clopidogrel users (18.2% vs. 0%, P = 0.02). In patient- and polyp-based logistic regression analysis of clopidogrel users, the number of EMRs (OR 2.12, 95% CI 1.16-3.88), polyp size (OR 1.26, 95% CI 1.06-1.49), and continuing clopidogrel (OR 9.75, 95% CI 1.99-47.64) were independent risk factors for PPB. CONCLUSION: Continuous administration of antiplatelet agents was significantly associated with higher PPB in clopidogrel users, but not in aspirin users. Endoscopists should consider holding clopidogrel if the EMR includes polypectomy.

Detection of SARS-CoV-2 in Fecal Samples From Patients With Asymptomatic and Mild COVID-19 in Korea.

BACKGROUND & AIMS: Although coronavirus disease 2019 (COVID-19) is characterized by fever and respiratory symptoms, some patients have no or mild symptoms. Severe acute respiratory syndrome-coronavirus (SARS-CoV-2) has been detected in feces of patients. We investigated gastrointestinal symptoms and shedding of virus into feces of patients with asymptomatic or mild COVID-19. METHODS: We collected data from 46 patients (median age, 26 y; 46% men) with asymptomatic or mild COVID-19 (without fever and pneumonia) and prolonged respiratory shedding of SARS-CoV-2, quarantined from April 4, 2020, through April 24, 2020, in Korea. Respiratory specimens included upper respiratory specimens (nasopharyngeal and oropharyngeal swabs) and lower respiratory specimens (sputum), and were collected twice per week. The median interval between COVID-19 diagnosis to the start of fecal sample collection was 37 days (range, 29-41 d); 213 stool specimens were collected from 46 patients. We used real-time reverse-transcription polymerase chain reaction to detect SARS-CoV-2 in the respiratory and fecal specimens. RESULTS: Gastrointestinal manifestations were observed in 16 of the 46 patients (35%); diarrhea was the most common (15%), followed by abdominal pain (11%), dyspepsia (11%), and nausea (2%). Virus RNA was detected in feces from 2 patients without gastrointestinal symptoms (4%). Mean cycle threshold values from the time of quarantine to the time of fecal collection tended to be lower in patients with virus detected in fecal samples than in patients without virus in fecal samples (29.91 vs 33.67 in the first week, 29.47 vs 35.71 in the fifth week, respectively). Shedding of virus into feces persisted until day 50 after diagnosis; fecal samples began to test negative before or at approximately the time that respiratory specimens also began to test negative. CONCLUSIONS: In an analysis of fecal and respiratory specimens from patients with COVID-19 in quarantine in Korea, we found that the gastrointestinal tract could be a route of transmission of SARS-CoV-2 even in patients with asymptomatic or mild disease, with no gastrointestinal symptoms. The viral load of the respiratory specimens appears be related to shedding of the virus into feces in this group of patients.

Optimization of the surveillance strategy in patients with colorectal adenomas: A combination of clinical parameters and index colonoscopy findings.

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.

Effect of Cotinine-Verified Change in Smoking Status on Risk of Metachronous Colorectal Neoplasia After Polypectomy.

BACKGROUND & AIMS: Previous assessments of colorectal neoplasia (CRN) recurrence after polypectomy used self-report to determine smoking status. We evaluated the association between change in smoking status and metachronous CRN risk after polypectomy using cotinine level in urine to determine tobacco exposure. METHODS: We performed a retrospective study of participants in the Kangbuk Samsung Health Study in Korea who underwent a screening colonoscopy examination and measurement of cotinine in urine samples. Our analysis included 4762 patients who had 1 or more adenomas detected in an index colonoscopy performed between January 2010 and December 2014, and underwent a surveillance colonoscopy, 6 or more months later, until December 2017. RESULTS: Patients were classified into 4 groups based on the change in cotinine-verified smoking status from index to follow-up colonoscopy (mean interval, 3.2 ± 1.3 y), as follows: remained nonsmokers (n = 2962; group 1), smokers changed to nonsmokers (n = 600; group 2), nonsmokers changed to smokers (n = 138; group 3), and remained smokers (n = 1062; group 4). After adjustment for confounding factors, group 4 had a significantly higher risk of metachronous CRN than group 1 (hazard ratio [HR], 1.54; 95% CI, 1.36-1.73) and group 2 (HR, 1.63; 95% CI, 1.39-1.99). Group 4 also had a higher risk of metachronous advanced CRN than group 1 (HR, 2.84; 95% CI, 1.79-4.53) and group 2 (HR, 2.10; 95% CI, 1.13-3.89). Group 3 had a higher risk of metachronous CRN than group 1 (HR, 1.50; 95% CI, 1.14-1.97) and group 2 (HR, 1.62; 95% CI, 1.20-2.20). CONCLUSIONS: In a retrospective study of individuals with at least 1 adenoma, we found that cotinine-verified changes in smoking status between index and follow-up colonoscopy are associated with a risk of metachronous CRN. Helping patients quit smoking is important for effective prevention of colorectal cancer.

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.

Risk of developing metachronous advanced colorectal neoplasia after resection of low-risk diminutive versus small adenomas.

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.

Skeletal muscle mass and risk of advanced adenoma in surveillance colonoscopy.

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.

Simple proxies for detection of clinically significant serrated polyps and data for their benchmarks.

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.

Association between waist circumference and risk of colorectal neoplasia in normal-weight adults.

BACKGROUND AND AIM: Abdominal obesity, measured using waist circumference (WC), is associated with the colorectal neoplasia (CRN) risk. We examined whether WC is associated with the CRN risk even in normal-weight individuals. METHODS: A cross-sectional study was performed on asymptomatic normal-weight (body mass index 18.5-23 kg/m2 ) individuals who underwent colonoscopy as health checkups. RESULTS: Of 63 057 examinees, 30 498 were men (mean age, 41.1 years) and 32 559 were women (mean age, 41.7 years). The prevalence of overall CRN in WC quartiles 1, 2, 3, and 4 was 14.2%, 15.5%, 15.5%, and 18.7%, respectively, in men and 7.4%, 8.9%, 9.4%, and 11.5%, respectively, in women. The prevalence of advanced CRN (ACRN) in WC quartiles 1, 2, 3, and 4 was 1.5%, 1.3%, 1.6%, and 2.1%, respectively, in men and 1.0%, 1.3%, 1.2%, and 1.3%, respectively, in women. Among men, the overall CRN risk in quartile 4 (> 82 cm) was higher than that in quartiles 1, 2, and 3 (adjusted odds ratio, OR [95% confidence interval, CI], 1.22 [1.11-1.34], 1.12 [1.05-1.23], and 1.18 [1.07-1.29], respectively); the ACRN risk in quartile 4 was also higher than that in quartiles 1, 2, and 3 (adjusted OR [95% CI], 1.41 [1.09-1.81], 1.56 [1.19-2.03], and 1.50 [1.16-1.94], respectively). Among women, the overall CRN risk in quartile 4 (> 77 cm) was higher than that in quartiles 1 and 3; the ACRN risk was not different among all groups. CONCLUSIONS: Even with a normal weight, a large WC was associated with the CRN risk, especially with the ACRN risk in men.

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.

Prevalence of and Risk Factors for Colorectal Neoplasia in Asymptomatic Young Adults (20-39 Years Old).

BACKGROUND & AIMS: The incidence of colorectal cancer is increasing among persons 50 years old or younger. However, data on the epidemiology of young-onset colorectal neoplasia (CRN) are limited. Although some studies have investigated the epidemiology of CRN in persons younger than 50 years, most have focused on persons 40 years or older. We evaluated the prevalence of and risk factors for CRN in adults younger than 40 years. METHODS: We performed a cross-sectional analysis of 72,356 asymptomatic individuals, 20-39 years old, who underwent colonoscopies as participants in the Kangbuk Samsung Health Study in South Korea, from August 2004 through December 2015. Data on medical history and health-related behavior were collected from self-administered questionnaires. Patients were divided into groups based on age (20-29 years, n = 7340 or 30-39 years, n = 65,016), and χ2 tests were used to compare categorical variables between groups. A multivariate logistic regression model was used to assess the risk factors for overall and advanced CRN. RESULTS: The prevalence of overall CRN in group of 20-29 years was 5.9% and in the group of 30-39 years was 9.5% (P < .001); prevalence values for advanced CRN were 0.6% and 0.9%, respectively (P = .005). In the group of 30-39 years, age, smoking, alcohol intake, obesity, and abdominal obesity were independent risk factors for overall and advanced CRN. Additionally, male sex and metabolic syndrome were independent risk factors for overall CRN, whereas regular exercise reduced risk of overall CRN. Even in the 20-29 years group, obesity, abdominal obesity, and increased levels of triglycerides were independent risk factors for overall and advanced CRN, whereas age, increased blood pressure, and increased fasting blood glucose level were independent risk factors for overall CRN. CONCLUSION: In a retrospective analysis of 72,356 asymptomatic persons under 40 years of age evaluated by colonoscopy in Korea, we found modifiable factors, such as smoking, alcohol intake, obesity, and metabolic syndrome, to be significant risk factors for CRN-even in persons of 20-39 years old. Colorectal cancer screening strategies should consider these risk factors.

Risk of Developing Metachronous Advanced Colorectal Neoplasia After Polypectomy in Patients With Multiple Diminutive or Small Adenomas.

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.

High-Definition Chromoendoscopy Versus High-Definition White Light Colonoscopy for Neoplasia Surveillance in Ulcerative Colitis: A Randomized Controlled Trial.

OBJECTIVES: Although chromoendoscopy is currently the recommended mode of surveillance in patients with long-standing ulcerative colitis, it is technically challenging and requires a long procedure time. The aim of this study was to compare the dysplasia detection rate of high-definition white light endoscopy with random biopsy (HDWL-R) vs high-definition chromoendoscopy with targeted biopsy (HDCE-T). METHODS: This was a multicenter, prospective randomized controlled trial involving 9 tertiary teaching hospitals in South Korea. A total of 210 patients with long-standing ulcerative colitis were randomized to undergo either the HDWL-R group (n = 102) or HDCE-T group (n = 108). The detection rates of colitis-associated dysplasia (CAD) or all colorectal neoplasia from each trial arm were compared. RESULTS: There was no significant difference in the CAD detection rate between HDCE-T and HDWL-R groups (4/102, 3.9% vs 6/108, 5.6%, P = 0.749). However, HDCE-T showed a trend toward improved colorectal neoplasia detection compared with HDWL-R (21/102, 20.6% vs 13/108, 12.0%, P = 0.093). The median (range) time for colonoscopy withdrawal between the 2 groups was similar (17.6 [7.0-43.3] minutes vs 16.5 [6.3-38.1] minutes; P=0.212; for HDWL-R and HDCE-T, respectively). The total number of biopsies was significantly larger in the HDWL-R group (34 [12-72]) compared with the HDCE-T group (9 [1-20]; P < 0.001). DISCUSSION: On the basis of our prospective randomized controlled trial, HDCE-T was not superior to HDWL-R for detecting CADs.

Usefulness of risk stratification models for colorectal cancer based on fecal hemoglobin concentration and clinical risk factors.

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.

Yield of repeat colonoscopy in asymptomatic individuals with a positive fecal immunochemical test and recent colonoscopy.

BACKGROUND AND AIMS: A fecal immunochemical test (FIT) is often repeated annually, even after a recent colonoscopy. However, there are no published data on the proper approach to FIT-positive patients after a recent colonoscopy. We compared colorectal cancer (CRC) and advanced colorectal neoplasia (ACRN) prevalence based on the interval since the last colonoscopy. METHODS: We reviewed asymptomatic screenees aged ≥50 years who underwent FIT and colonoscopy. RESULTS: Of 2228 FIT-positive participants, 514 had a colonoscopy less than 3 years before (group 1), 427 had a colonoscopy had a colonoscopy 3 to 10 years before (group 2), and 1287 had a colonoscopy >10 years before or no colonoscopy (group 3). The prevalence of CRC in groups 1, 2, and 3 was 2.1%, 1.6%, and 7.2%, respectively, and that for ACRN was 10.9%, 12.6%, and 26.0%, respectively. Even after adjusting for confounders, CRC and ACRN detection rates in group 1 were lower than those in group 3 but not lower than those in group 2. Among 6135 FIT-negative participants, the prevalence of CRC in the 3 groups was .7%, .4%, and 3.4%, respectively, and that for ACRN was 6.0%, 6.1%, and 14.7%, respectively. CRC and ACRN detection rates were significantly higher in FIT-positive participants than in FIT-negative participants in all 3 groups. CONCLUSIONS: In FIT-positive patients who underwent colonoscopy within the prior 3 years, CRC and ACRN prevalence was not low. Our findings support the U.S. Multi-Society Task Force on the CRC screening recommendation that repeat colonoscopy be offered to patients with positive FIT results and recent colonoscopy.