Sung Noh Hong

Prospective, randomized, back-to-back trial evaluating the usefulness of i-SCAN in screening colonoscopy

BACKGROUND The newly developed i-SCAN application can theoretically maximize the effectiveness of colonoscopy. However, the practical usefulness of the i-SCAN application during screening colonoscopy has not been assessed. OBJECTIVE To assess the efficacy of the i-SCAN application during screening colonoscopy. DESIGN A prospective, randomized trial that used a modified, back-to-back colonoscopy. SETTING Academic hospital. PATIENTS This study involved 389 asymptomatic, consecutive, average-risk patients who underwent screening colonoscopy. INTERVENTION The patients were randomized to the first withdrawal with either conventional high-definition white light (HDWL group; n = 119), i-SCAN contrast/surface enhancement (CE/SE) mode (i-SCAN1 group; n = 115), or i-SCAN CE/SE/tone enhancement-colorectal mode (i-SCAN2 group; n = 118). All patients underwent a second examination with HDWL as the criterion standard. MAIN OUTCOME MEASUREMENTS The primary outcome measurement was the adenoma detection rate and adenoma miss rate. The secondary outcome measurement was the accuracy of the histologic prediction of neoplastic and nonneoplastic polyps. RESULTS The adenoma detection rates during the first withdrawal of HDWL, i-SCAN1, and i-SCAN2 were 31.9%, 36.5%, and 33.1%, respectively (P = .742), and the adenoma miss rates of each group were 22.9%, 19.3%, and 15.9%, respectively (P = .513). Based on the multivariate analysis, the application of i-SCAN was not associated with an improvement in adenoma detection and the prevention of missed polyps. However, the prediction of neoplastic and nonneoplastic colorectal lesions was more precise in the i-SCAN2 group compared with the HDWL group (accuracy 79.3% vs 75.5%, P = .029; sensitivity 86.5% vs 72.6%, P = .020; and specificity 91.4% vs 80.6%, P = .040). LIMITATIONS Single-center trial. CONCLUSION i-SCAN during the screening colonoscopy may fail to improve adenoma detection and the prevention of missed polyps, but i-SCAN appears to be effective for real-time histologic prediction of polyps compared with conventional HDWL colonoscopy. ( CLINICAL TRIAL REGISTRATION NUMBER NCT01417611.).

The Effect of the Bowel Preparation Status on the Risk of Missing Polyp and Adenoma during Screening Colonoscopy: A Tandem Colonoscopic Study

Background/Aims Although a small amount of fecal material can obscure significant colorectal lesions, it has not been well documented whether bowel preparation status affects the missing risk of colorectal polyps and adenomas during a colonoscopy. Methods We prospectively enrolled patients with one to nine colorectal polyps and at least one adenoma of >5 mm in size at the screening colonoscopy. Tandem colonoscopy with polypectomy was carried out within 3 months. Results A total of 277 patients with 942 polyps and 714 adenomas completed index and tandem examinations. At the index colonoscopy, 187 polyps (19.9%) and 127 adenomas (17.8%) were missed. The per-patient miss rate of polyps and adenomas increased significantly as the bowel cleansing rate declined from excellent to poor/inadequate on the Aronchick scale (polyps, p=0.024; adenomas, p=0.040). The patients with poor/inadequate bowel preparation were independently associated with an increased risk of having missed polyps (odds ratio [OR], 3.21; 95% confidence interval [CI], 1.13 to 9.15) or missed adenomas (OR, 3.04; 95% CI, 1.04 to 8.88) compared to the patients with excellent bowel preparation. Conclusions The risk of missing polyps and adenomas during screening colonoscopy is significantly affected by bowel preparation status. It seems appropriate to shorten the colonoscopy follow-up interval for patients with suboptimal bowel preparation.

Korean Guidelines for Colorectal Cancer Screening and Polyp Detection

Now colorectal cancer is the second most common cancer in males and the fourth most common cancer in females in Korea. Since most of colorectal cancers occur after the prolonged transformation of adenomas into carcinomas, early detection and removal of colorectal adenomas are one of the most effective methods to prevent colorectal cancer. Considering the increasing incidence of colorectal cancer and polyps in Korea, it is very important to establish Korean guideline for colorectal cancer screening and polyp detection. The guideline was developed by the Korean Multi-Society Take Force and we tried to establish the guideline by evidence-based methods. Parts of the statements were draw by systematic reviews and meta-analyses. Herein we discussed epidemiology of colorectal cancers and adenomas in Korea and optimal methods for screening of colorectal cancer and detection of adenomas including fecal occult blood tests, radiologic tests, and endoscopic examinations.

Prevalence and risk of colorectal neoplasms in asymptomatic, average-risk screenees 40 to 49 years of age

BACKGROUND A paucity of information exists regarding colorectal neoplasm in asymptomatic, average-risk individuals 40 to 49 years of age. OBJECTIVE To evaluate the prevalence and risk factors of colorectal neoplasms in those in their 40s. DESIGN Cross-sectional study. SETTING Results offered to subjects of a health care provider that offers screening services as part of an employer-provided wellness program. PATIENTS A consecutive series of 1761 asymptomatic, average-risk screenees 40 to 59 years of age. INTERVENTION First screening colonoscopy. RESULTS The prevalence of overall colorectal neoplasm in subjects of ages 40 to 44 years, 45 to 49 years, 50 to 54 years, and 55 to 59 years increased significantly with increasing age (13.7%, 20.2%, 21.0%, and 23.8%, respectively; P < .001). The prevalence of advanced adenomas in subjects of ages 40 to 44 years, 45 to 49 years, 50 to 54 years, and 55 to 59 years increased significantly with age (1.9%, 3.0%, 3.2%, and 5.9%, respectively; P = .004). Multivariate analysis of data from the 40- to 49-year age group identified an increased risk of colorectal neoplasm associated with ages 45 years and older (odds ratio [OR], 1.68; 95% CI, 1.20-2.35), male sex (OR, 1.76; 95% CI, 1.15-2.69), presence of abdominal obesity (OR, 1.57; 95% CI, 1.12-2.21), and metabolic syndrome (OR, 1.56; 95% CI, 1.03-2.35), whereas for advanced adenomas, abdominal obesity (OR, 2.37; 95% CI, 1.06-5.27) and metabolic syndrome (OR, 2.83; 95% CI, 1.23-6.53) were the independent risk factors. LIMITATIONS Single-center study and the cohort composed of ethnic Korean subjects who lived in the same geographic region. CONCLUSION In average-risk individuals 40 to 49 years of age, men with abdominal obesity or metabolic syndrome might benefit from screening colonoscopy starting at 45 years of age to detect colorectal neoplasm.

Korean Guidelines for Postpolypectomy Colonoscopy Surveillance

Postpolypectomy surveillance has become a major indication for colonoscopy as a result of increased use of screening colonoscopy in Korea. In this report, a careful analytic approach was used to address all available evidences to delineate the predictors for advanced neoplasia at surveillance colonoscopy and we elucidated the high risk findings of the index colonoscopy as follows: 3 or more adenomas, any adenoma larger than 10 mm, any tubulovillous or villous adenoma, any adenoma with high-grade dysplasia, and any serrated polyps larger than 10 mm. Surveillance colonoscopy should be performed five years after the index colonoscopy for those without any high-risk findings and three years after the index colonoscopy for those with one or more high risk findings. However, the surveillance interval can be shortened considering the quality of the index colonoscopy, the completeness of polypectomy, the patients general condition, and family and medical history.

Deep resequencing of 131 Crohn's disease associated genes in pooled DNA confirmed three reported variants and identified eight novel variants

Objective Genome wide association studies (GWAS) and meta-analyses for Crohns disease (CD) have not fully explained the heritability of CD, suggesting that additional loci are yet to be found and that the known loci may contain high effect rare risk variants that have thus far gone undetected by GWAS. While the cost of deep sequencing remains too high to analyse many samples, targeted sequencing of pooled DNA samples allows the efficient and cost effective capture of all variations in a target region. Design We performed pooled sequencing in 500 Korean CD cases and 1000 controls to evaluate the coding exon and 5′ and 3′ untranslated regions of 131 CD associated genes. The identified genetic variants were validated using genotyping in an independent set of 500 CD cases and 1000 controls. Results Pooled sequencing identified 30 common/low single nucleotide variants (SNVs) in 12 genes and 3 rare SNVs in 3 genes. Our results confirmed a significant association of CD with the following previously reported risk loci: rs3810936 in TNFSF15 (OR=1.83, p<2.2×10−16), rs76418789 in IL23R (OR=0.47, p=1.14×10−8) and rs2241880 in ATG16L1 (OR=1.30, p=5.28×10−6). In addition, novel loci were identified in TNFSF8 (rs3181374, OR=1.53, p=1.03×10−14), BTNL2 (rs28362680, OR=1.47, p=9.67×10−11), HLA-DQA2 (rs3208181, OR=1.36, p=4.66×10−6), STAT3 (rs1053004, OR=1.29, p=2.07×10−5), NFKBIA (rs2273650, OR=0.80, p=3.93×10−4), NKX2-3 (rs888208, OR=0.82, p=6.37×10−4) and DNAH12 (rs4462937, OR=1.13, p=3.17×10−2). A novel rare SNV, rs200735402 in CARD9, was shown to have a protective effect (OR=0.09, p=5.28×10−5). Conclusions Our deep resequencing of 131 CD associated genes confirmed 3 reported risk loci and identified 8 novel risk loci for CD in Koreans, providing new insights into the genetic architecture of CD.

Patients with Crohn's disease on anti-tumor necrosis factor therapy are at significant risk of inadequate response to the 23-valent pneumococcal polysaccharide vaccine

BACKGROUND/AIMS The effect of immunosuppressants on the efficacy of a variety of vaccines is a controversial issue in patients with inflammatory bowel disease (IBD). In this study we determined whether specific immunosuppressants impair the serological response to the standard 23-valent pneumococcal polysaccharide vaccine (PPSV23) in a large cohort of patients with Crohns disease (CD). METHODS This was a multi-center, prospective observational study of adult patients with CD at 15 academic teaching hospitals in Korea. The study population received one intramuscular injection of PPSV23. Anti-pneumococcal IgG antibody titers were measured by immunoassay prior to and 4weeks after vaccination. All vaccination-related adverse events and the effect of the vaccine on disease activity were also evaluated. RESULTS The overall serological response rate was 67.5% (133/197). The serological response rate was significantly lower in patients on anti-tumor necrosis factor (anti-TNF) therapy (50.0% on anti-TNF alone; 58.0% on anti-TNF combined with an immunomodulator, IM) than patients on 5-aminosalicylate (78.4%; all P-values vs. 5-aminosalicylate<0.05); 45.6% (41/90) of patients on anti-TNF therapy were not protected against PPSV23. IM did not affect the immunologic response to the vaccine. Female gender and anti-TNF therapy were significant predictors of non-response to the vaccine (odds ratio [OR] 2.316, P=0.015; OR 2.582, P=0.048, respectively). Vaccination was generally safe and tolerated by all patients. CONCLUSIONS Patients with CD on anti-TNF therapy are at significant risk of an inadequate response to PPSV23. The pneumococcal vaccination strategy should be optimized for patients with CD on anti-TNF therapy.

Establishment of reference interval for immature platelet fraction

Immature platelet fraction (IPF) is a parameter for reticulated platelets. A high percentage IPF (%‐IPF) is indicative of consumptive or recovering thrombocytopenic disorders in contrast to a low %‐IPF seen in aplastic states. Absolute IPF (A‐IPF) specifically reflects the number of immature platelets in circulation. This study aimed to establish reliable reference intervals for %‐IPF and A‐IPF.

Korean Guideline for Colonoscopic Polypectomy

There is indirect evidence to suggest that 80% of colorectal cancers (CRC) develop from adenomatous polyps and that, on average, it takes 10 years for a small polyp to transform into invasive CRC. In multiple cohort studies, colonoscopic polypectomy has been shown to significantly reduce the expected incidence of CRC by 76% to 90%. Colonoscopic polypectomy is performed frequently in primary outpatient clinics and secondary and tertiary medical centers in Korea. However, there are no evidence-based, procedural guidelines for the appropriate performance of this procedure, including the technical aspects. For the guideline presented here, PubMed, Medline, and Cochrane Library literature searches were performed. When little or no data from well-designed prospective trials were available, an emphasis was placed on the results from large series and reports from recognized experts. Thus, these guidelines for colonoscopic polypectomy are based on a critical review of the available data as well as expert consensus. Further controlled clinical studies are needed to clarify aspects of this statement, and revision may be necessary as new data become available. This guideline is intended to be an educational device to provide information that may assist endoscopists in providing care to patients. This guideline is not a rule and should not be construed as a legal standard of care or as encouraging, advocating, requiring, or discouraging any particular treatment. Clinical decisions for any particular case involve a complex analysis of the patients condition and the available courses of action.

Helicobacter pylori infection is an independent risk factor of early and advanced colorectal neoplasm.

The role of Helicobacter pylori (H. pylori) in the development of colorectal neoplasm remains controversial. We examined the association between H. pylori infection and colorectal neoplasm in a large sample of healthy participants who underwent screening colonoscopy.