Clinical factors associated with stable treatment of chronic constipation in Japanese patients.

BACKGROUND/AIMS: Chronic constipation (CC) is one of the most common gastrointestinal disorders in the general population. Although there are many treatment options, achieving a stable treatment for CC remains one of the challenges in clinical practice. This study aimed to evaluate the clinical factors associated with stable treatment for CC in Japanese patients. METHODS: A retrospective, cross-sectional, and multicenter study was carried out. Patients were eligible for inclusion if they fulfilled the Rome IV criteria for diagnosing CC and had been treated for at least one and a half years. Patients with up to two prescription modifications for CC in one year were defined as the stable treatment group, whereas those with three or more prescription changes were defined as the unstable treatment group. Univariate and multivariate analyses were carried out to identify factors associated with CC. RESULTS: A total of 114 patients have been recruited. There were 82 patients (77.0%) in the stable treatment group and 32 patients (23.0%) in the unstable treatment group. Based on multivariate likelihood analysis, only using acid-suppressive drugs contributed to stability treatment in CC patients (odds ratio: 2.81, 95% confidence interval: 1.12-7.08, p = 0.03). CONCLUSION: Administration of acid-suppressive drugs was the only factor related to the stability of CC treatment. Further studies are needed to validate the results as well as clarify the causes.

Performance of the Asia-Pacific Colorectal Screening score in stratifying the risk of advanced colorectal neoplasia: A meta-analysis and systematic review.

BACKGROUND AND AIM: This study systematically reviewed and meta-analyzed the performance of the Asia-Pacific Colorectal Screening (APCS) score and its incorporation with the fecal immunochemical test (FIT) in stratifying the risk of advanced colorectal neoplasia (ACN). METHODS: We systematically searched for relevant articles in 12 electronic databases and registers on October 20, 2021, and updated the search to September 1, 2023. Random-effect models were used to obtain the pooled performance statistics of the APCS score for ACN risk. RESULTS: From the 101 records screened, 13 eligible studies in the Asia-Pacific region involving 69 762 subjects who had undergone colonoscopy were enrolled. The pooled prevalences of ACN in the average-risk (AR) tier (APCS 0-1), moderate-risk (MR) tier (APCS 2-3), and high-risk (HR) tier (APCS ≥ 4) groups were 0.9%, 3.1%, and 8.1%, respectively. Compared with the combined AR-MR group, the HR group was significantly associated with a higher ACN risk (pooled diagnostic odds ratio: 2.84, 95% confidence interval [CI]: 2.35-3.45, P < 0.001). The APCS score showed a sensitivity of 0.42 (95% CI: 0.40-0.44) and a specificity of 0.86 (95% CI: 0.85-0.86) for predicting the ACN risk, with a weighted area under the curve of 0.642 (95% CI: 0.610-0.657). The combination of the APCS score and FIT substantially improved ACN risk identification, demonstrating pooled diagnostic odds ratios of 4.02 (95% CI: 2.50-6.49) in the AR-MR groups and 5.44 (95% CI: 1.89-15.63) in the MR-HR groups. CONCLUSIONS: The APCS score could effectively stratify the ACN risk in the Asia-Pacific population. Incorporating FIT further improves its performance in identifying high-risk subjects who should be prioritized for colonoscopy screenings.

Endoscopic Kyoto and Kimura-Takemoto Classifications Are Comparable in Predicting High-Risk Gastric Precancerous Lesions.

INTRODUCTION: Severe and extensive gastric atrophy, extensive or incomplete gastric intestinal metaplasia, and gastric dysplasia are considered high-risk gastric precancerous lesions (HGPLs). Endoscopic findings based on the endoscopic Kyoto classification (EKC) and the Kimura-Takemoto classification (KTC) have been reported to be significantly associated with HGPLs. This study aimed to compare these two classifications in predicting active Helicobacter pylori (H. pylori) infection and HGPLs. METHODS: This is a cross-sectional study conducted on naïve dyspeptic patients who underwent upper gastrointestinal endoscopy at a tertiary hospital. Endoscopic findings were scored according to the EKC and KTC. Mapping biopsies were taken, and H. pylori infection was determined using a locally validated rapid urease test and histology. The performance of EKC was compared with that of KTC using the area under the receiver operating characteristic curve (AUC) in predicting active H. pylori infection and HGPLs. RESULTS: There were 292 patients with a median age of 46 and a male-to-female ratio of 1:1. The rates of active H. pylori infection and HGPLs were 61.3% and 14.0%, respectively. The EKC was better than the KTC in predicting active H. pylori infection (AUC: 0.771 vs. 0.658, respectively; p < 0.001). However, these two classifications had comparable performance in predicting HGPLs (AUC: 0.792 vs. 0.791, respectively; p = 0.956). CONCLUSION: Compared to EKC, KTC is inferior in predicting active H. pylori infection but has comparable performance in predicting HGPLs.

Real-world practice of Helicobacter pylori management: A survey among physicians in Southeast Asia.

BACKGROUND: Multidrug-resistant Helicobacter pylori strains are emerging in Southeast Asia. This study evaluates the region's real-world practice in H. pylori management. MATERIALS AND METHODS: Physicians who managed H. pylori eradication in daily practice across 10 Southeast Asian countries were invited to participate in an online questionnaire, which included questions about the local availability of antimicrobial susceptibility tests (ASTs) and their preferred eradication regimens in real-world practice. An empiric regimen was considered inappropriate if it did not follow the local guidelines/consensus, particularly if it contained antibiotics with a high reported resistance rate or was recommended not to be empirically used worldwide. RESULTS: There were 564 valid responses, including 314 (55.7%) from gastroenterologists (GIs) and 250 (44.3%) from non-GI physicians. ASTs were unavailable in 41.7%. In countries with low and intermediate clarithromycin resistance, the most common first-line regimen was PAC (proton pump inhibitor [PPI], amoxicillin, clarithromycin) (72.7% and 73.2%, respectively). Regarding second-line therapy, the most common regimen was bismuth-based quadruple therapy, PBMT (PPI, bismuth, metronidazole, tetracycline) (50.0% and 59.8%, respectively), if other regimens were used as first-line treatment. Concomitant therapy (PPI, amoxicillin, clarithromycin, metronidazole) (30.5% and 25.9%, respectively) and PAL (PPI, amoxicillin, levofloxacin) (22.7% and 27.7%, respectively) were favored if PBMT had been used as first-line treatment. In countries with high clarithromycin resistance, the most common first-line regimen was PBMT, but the utilization rate was only 57.7%. Alarmingly, PAC was prescribed in 27.8% of patients, ranking as the second most common regimen, and its prescription rate was higher in non-GI physicians than GI physicians (40.1% vs. 16.2%, p < 0.001). CONCLUSIONS: Choosing inappropriate regimens containing antibiotics with high resistance rates is not uncommon in Southeast Asia, especially among non-GI physicians. In countries with high clarithromycin resistance, the PBMT regimen is underutilized.

Helicobacter pylori World Gastroenterology Organization Global Guideline.

Helicobacter pylori remains a major health problem worldwide, causing considerable morbidity and mortality due to peptic ulcer disease and gastric cancer. The burden of disease falls disproportionally on less well-resourced populations. As with most infectious diseases, the largest impact on reducing this burden comes from improvement in socioeconomic status, which interrupts transmission. This has been observed in many regions of the world, but the prevalence of infection remains high in many regions where improvements in living standards are slow to occur. Meanwhile, the optimal clinical management and treatment pathways remain unsettled and are evolving with changing antimicrobial resistance patterns. Despite decades of research and clinical practice, major challenges remain. The quest for the most effective, safe, and simple therapy remains the major issue for clinicians. The search for an effective vaccine appears to be elusive still. Clinical guidelines do not infrequently proffer discordant advice. A major challenge for guidelines is for relevance across a variety of populations with a varying spectrum of disease, antimicrobial resistance rates, and vastly different resources. As local factors are central to determining the impact and management strategies for H. pylori infection, it is important that pathways are based on the best available local knowledge rather than solely extrapolating from guidelines formulated in other regions, which may be less applicable. To this end, this revision of the World Gastroenterology Organisation (WGO) H. pylori guideline uses a "Cascades" approach that seeks to summarize the principles of management and offer advice for pragmatic, relevant and achievable diagnostic and treatment pathways based on established key treatment principles and using local knowledge and available resources to guide regional practice.

Knowledge of common cancers among new-entry health science students in Japan and Vietnam.

BACKGROUND: The incidence and mortality rates of cancer are rapidly increasing worldwide. This study aimed to assess the knowledge of common cancers among new-entry health science students in Japan and Vietnam, thereby providing insights for implementing appropriate medical educational interventions. METHODS: This cross-sectional study was conducted among new-entry health science students at Hiroshima University, Japan, and the University of Medicine and Pharmacy at Ho Chi Minh City, Vietnam. A printed predesigned questionnaire consisting of eleven questions was distributed to the participants during the freshmen health screening at the beginning of the academic year to assess their knowledge of cancer. RESULTS: A total of 2,748 new-entry health science students participated in the study, including 394 (14.3%) Japanese students and 2,354 (85.7%) Vietnamese students. Most cancer knowledge levels in Japanese students were significantly higher than those in Vietnamese students (p < 0.001), except for human papillomavirus (HPV) infection awareness. For this understanding, only 14.8% of Japanese students selected the correct answer, which was significantly lower than the 22.4% of Vietnamese students (p = 0.001). Both the Japanese and Vietnamese students had limited knowledge regarding the connection between HPV infection and cancer and the link between estrogen-progestogen menopausal therapy and breast cancer. Additionally, female students had better knowledge about breast, skin, and endometrial cancers than male students. CONCLUSIONS: Japanese students generally exhibited higher levels of cancer knowledge than Vietnamese students, except for HPV infection recognition. Both groups had limited knowledge regarding the connection between HPV infection and cancer and the relationship between estrogen-progestogen menopausal therapy and breast cancer.

Emergence of amoxicillin resistance and identification of novel mutations of the pbp1A gene in Helicobacter pylori in Vietnam.

BACKGROUND: Amoxicillin-resistant Helicobacter pylori (H. pylori) strains seem to have increased over time in Vietnam. This threatens the effectiveness of H. pylori eradication therapies with this antibiotic. This study aimed to investigate the prevalence of primary resistance of H. pylori to amoxicillin and to assess its association with pbp1A point mutations in Vietnamese patients. MATERIALS AND METHODS: Naive patients who presented with dyspepsia undergoing upper gastrointestinal endoscopy were recruited. Rapid urease tests and PCR assays were used to diagnose H. pylori infection. Amoxicillin susceptibility was examined by E-tests. Molecular detection of the mutant pbp1A gene conferring amoxicillin resistance was carried out by real-time PCR followed by direct sequencing of the PCR products. Phylogenetic analyses were performed using the Tamura-Nei genetic distance model and the neighbor-joining tree building method. RESULTS: There were 308 patients (46.1% men and 53.9% women, p = 0.190) with H. pylori infection. The mean age of the patients was 40.5 ± 11.4 years, ranging from 18 to 74 years old. The E-test was used to determine the susceptibility to amoxicillin (minimum inhibitory concentration (MIC) ≤ 0.125 µg/ml) in 101 isolates, among which the rate of primarily resistant strains to amoxicillin was 25.7%. Then, 270 sequences of pbp1A gene fragments were analysed. There were 77 amino acid substitution positions investigated, spanning amino acids 310-596, with the proportion varying from 0.4 to 100%. Seven amino acid changes were significantly different between amoxicillin-sensitive (AmoxS) and amoxicillin-resistant (AmoxR) samples, including Phe366 to Leu (p <  0.001), Ser414 to Arg (p <  0.001), Glu/Asn464-465 (p = 0.009), Val469 to Met (p = 0.021), Phe473 to Val (p <  0.001), Asp479 to Glu (p = 0.044), and Ser/Ala/Gly595-596 (p = 0.001). Phylogenetic analyses suggested that other molecular mechanisms might contribute to amoxicillin resistance in H. pylori in addition to the alterations in PBP1A. CONCLUSIONS: We reported the emergence of amoxicillin-resistant Helicobacter pylori strains in Vietnam and new mutations statistically associated with this antimicrobial resistance. Additional studies are necessary to identify the mechanisms contributing to this resistance in Vietnam.

Performance of chromoendoscopy and narrow-band imaging in the diagnosis of gastric intestinal metaplasia.

BACKGROUND/AIMS: Chromoendoscopy and narrow-band imaging (NBI) have been reported to aid in the diagnosis of gastric intestinal metaplasia (GIM). This study aimed to assess the diagnostic validity of chromoendoscopy combined with NBI in the diagnosis of GIM in Vietnamese. METHODS: A cross-sectional study was carried out on patients with dyspeptic symptoms who underwent esophagogastroduodenoscopy (EGD) at the University Medical Center at Ho Chi Minh City. We compared the detection rates of GIM in the group of patients examined with white-light endoscopy (WLE) alone and those examined with WLE in combination with chromoendoscopy and NBI. RESULTS: A total of 374 patients have been recruited. The additional GIM detection rate after chromoendoscopy combined with NBI was 8.6% (95% confidence interval [CI]: 4.3 - 12.8), p < .005. The rate of GIM within the group of patients biopsied under the guidance of chromoendoscopy combined with NBI was statistically significantly higher than in the group with WLE alone with a distinct rate of 14.4% (95% CI: 6.3 - 2.6), p = .001. CONCLUSIONS: Chromoendoscopy combined with NBI helped to detect the GIM lesions missed by WLE and was a more reliable endoscopic method for the diagnosis of GIM.

Efficacy of international web-based educational intervention in the detection of high-risk flat and depressed colorectal lesions higher (CATCH project) with a video: Randomized trial.

OBJECTIVES: Three subcategories of high-risk flat and depressed lesions (FDLs), laterally spreading tumors non-granular type (LST-NG), depressed lesions, and large sessile serrated lesions (SSLs), are highly attributable to post-colonoscopy colorectal cancer (CRC). Efficient and organized educational programs on detecting high-risk FDLs are lacking. We aimed to explore whether a web-based educational intervention with training on FIND clues (fold deformation, intensive stool/mucus attachment, no vessel visibility, and demarcated reddish area) may improve the ability to detect high-risk FDLs. METHODS: This was an international web-based randomized control trial that enrolled non-expert endoscopists in 13 Asian countries. The participants were randomized into either education or non-education group. All participants took the pre-test and post-test to read 60 endoscopic images (40 high-risk FDLs, five polypoid, 15 no lesions) and answered whether there was a lesion. Only the education group received a self-education program (video and training questions and answers) between the tests. The primary outcome was a detection rate of high-risk FDLs. RESULTS: In total, 284 participants were randomized. After excluding non-responders, the final data analyses were based on 139 participants in the education group and 130 in the non-education group. The detection rate of high-risk FDLs in the education group significantly improved by 14.7% (66.6-81.3%) compared with -0.8% (70.8-70.0%) in the non-education group. Similarly, the detection rate of LST-NG, depressed lesions, and large SSLs significantly increased only in the education group by 12.7%, 12.0%, and 21.6%, respectively. CONCLUSION: Short self-education focusing on detecting high-risk FDLs was effective for Asian non-expert endoscopists. (UMIN000042348).

Short Meal-to-Bed Time Is a Predominant Risk Factor of Gastroesophageal Reflux Disease in Pregnancy.

BACKGROUND: Short meal-to-bed time (MTBT) has been reported to relate to gastroesophageal reflux disease (GERD), but evidence is lacking in pregnant women. We aimed to assess the characteristics of GERD and the association between MTBT and GERD during pregnancy. PATIENTS AND METHODS: A cross-sectional study was carried out on 400 pregnant women aged 18 years and older visiting the antenatal clinic of Gia-Dinh People's Hospital, Vietnam. GERD was defined as having troublesome heartburn and/or regurgitation at least once a week. Reflux-related insomnia was defined as having difficulties in initiating or maintaining sleep through the night. MTBT was defined as "short" if it was ≤2 hours in more than two thirds of days in a week. RESULTS: There were 154 (38.5%) patients with GERD and 20 (13.0%) patients with reflux-related insomnia. In multivariate analysis, there were 3 factors significantly associated with GERD: third trimester [odds ratio (OR)=1.66; 95% confidence interval (CI): 1.03-2.69], previous history of typical reflux symptoms (OR=9.05; 95% CI: 5.29-15.50), and short MTBT (OR=12.73; 95% CI: 2.92-55.45). The frequency of reflux symptoms progressively increased across subgroups of patients with no short MTBT, either daytime or nighttime short MTBT, and with both daytime and nighttime short MTBT. Nighttime MTBT was also a significant risk factor for reflux-related insomnia (OR=4.60; 95% CI: 1.64-12.92). CONCLUSIONS: We reported for the first time that short MTBT was a predominant risk factor of GERD in pregnancy. This dieting habit was significantly associated with reflux symptom frequency and reflux-related insomnia.

Development and Validation of a Scoring System to Predict Severe Acute Lower Gastrointestinal Bleeding in Vietnamese.

BACKGROUND/AIMS: The prevalence of acute lower gastrointestinal bleeding (ALGIB) has progressively increased worldwide but there are few studies in Asian populations. This study aimed to develop and validate a scoring system to predict severe ALGIB in Vietnamese. METHODS: Risk factors for severe ALGIB were identified by multiple logistic regression analysis using data from a retrospective cohort of 357 patients admitted to a tertiary hospital. These factors were weighted to develop the severe acute lower gastrointestinal bleeding (SALGIB) score to predict severe ALGIB. The performance of SALGIB was validated in a prospective cohort of 324 patients admitted to 6 other hospitals using area under the receiver operating characteristics curve (AUC) analysis. RESULTS: There were four factors at admission independently associated with severe ALGIB in the derivation cohort: heart rate ≥ 100/min, systolic blood pressure < 100 mmHg, hematocrit < 35%, and platelets ≤ 150 × 103/µL. The SALGIB score determined severe ALGIB with AUC values of 0.91 and 0.86 in the derivation and validation cohorts, respectively. A SALGIB score < 2 associated with low risk of severe ALGIB in both cohorts (3.7% and 1.2%; respectively). CONCLUSIONS: The SALGIB score has good performance in discriminating risk of severe ALGIB in Vietnamese.

Use of endoscopic assessment of gastric atrophy for gastric cancer risk stratification to reduce the need for gastric mapping.

Background/Aims: Stratification for gastric cancer risk typically involves histologic grading of gastric biopsies. This study aimed to compare endoscopic assessment of gastric atrophy and histologic gastric mapping for gastric cancer risk stratification in a region with relatively high risk of gastric cancer.Methods: Endoscopic and histologic gastric cancer risk stratification were compared in Vietnamese patients with functional dyspepsia. Endoscopic gastric atrophy was graded according to the Kimura-Takemoto classification. High-risk histologic lesions were defined as gastric dysplasia, Operative Link on Gastritis Assessment (OLGA) gastritis stage III/IV, intestinal metaplasia in both the antrum and the corpus or incomplete intestinal subtype at any site. Two experienced pathologists, blinded to endoscopic information, jointly examined all specimens and reached a consensus. The presence of high-risk histologic lesions was compared among patients with different endoscopic grades of gastric atrophy.Results: There were 280 subjects (mean age, 46.1 ± 10 years, and male, 50%). The numbers of patients with moderate/severe grade of endoscopic gastric atrophy and high-risk histologic lesions were 126 (45.0%) and 46 (16.4%), respectively. The sensitivity, specificity, positive and negative likelihood ratios of moderate/severe endoscopic atrophic grade for detecting high-risk histologic lesions were 93% (95% CI 86%-100%), 65% (95% CI 58%-71%), 2.64 (95% CI 2.18 - 3.18) and 0.10 (95% CI 0.03 - 0.30), respectively.Conclusions: Gastric cancer risk assessment using endoscopic or histologic methods provided similar results such that the absence or a mild grade of endoscopic gastric atrophy would preclude the need for histologic mapping.

Asia-Pacific Colorectal Screening score: A useful tool to stratify risk for colorectal advanced neoplasms in Vietnamese patients with irritable bowel syndrome.

BACKGROUND AND AIM: The Asia-Pacific Colorectal Screening (APCS) score has been validated in several populations but not yet in patients with irritable bowel syndrome (IBS). The aim of this study was to assess the performance of APCS score in stratifying risk of colorectal advanced neoplasms (CAN) in Vietnamese IBS patients. METHODS: Consecutive patients who fulfilled IBS diagnosis criteria according to the Rome III were prospectively enrolled and underwent colonoscopy. APCS score for each patient was calculated by summing the points attributed by risk factors. Three tiers of risk were defined: 0-1 "average risk" (AR); 2-3 "moderate risk" (MR); and 4-7 "high risk" (HR). Logistic regression analysis was performed to assess the relative risk of CAN in HR group and MR group compared with AR group. RESULTS: There were 404 patients with excellent bowel preparation and complete colonoscopy. The mean age was 48.8 ± 11.2 years and male : female ratio was 1.2:1. Twenty-eight patients (6.9%) were diagnosed with CAN: 19 (4.7%) advanced adenoma and 9 (2.2%) invasive colorectal cancer. Patients in the MR and HR tiers had 5.6-fold (95% confidence interval 1.2 to 24.7, P = 0.012) and 12.1-fold (95% confidence interval 2.6 to 56.2, P < 0.001) increased rates of CAN compared with those in the AR tier, respectively. Three out of 9 patients with invasive colorectal cancer had no alarm features but had high sum APCS score (2 in MR tier and 1 in HR tier). CONCLUSION: The APCS score is useful to identify IBS patients with high risk of CAN for colonoscopy priority.

Helicobacter pylori management in ASEAN: The Bangkok consensus report.

Helicobacter pylori (H. pylori) infection remains to be the major cause of important upper gastrointestinal diseases such as chronic gastritis, peptic ulcer, gastric adenocarcinoma, and mucosa-associated lymphoid tissue lymphoma. H. pylori management in ASEAN: the Bangkok consensus report gathered key opinion leaders for the region to review and evaluate clinical aspects of H. pylori infection and to develop consensus statements, rationales, and grades of recommendation for the management of H. pylori infection in clinical practice in ASEAN countries. This ASEAN Consensus consisted of 34 international experts from 10 ASEAN countries, Japan, Taiwan, and the United States. The meeting mainly focused on four issues: (i) epidemiology and disease association; (ii) diagnostic tests; (iii) management; and (iv) follow-up after eradication. The final results of each workshop were presented for consensus voting by all participants. Statements, rationale, and recommendations were developed from the available current evidence to help clinicians in the diagnosis and treatment of H. pylori and its clinical diseases.

Magnifying Endoscopy with Narrow Band Imaging in Estimating the Invasion Depth of Superficial Esophageal Squamous Cell Carcinomas.

BACKGROUND/AIM: The aim of this study was to compare the accuracy of magnifying endoscopy with narrow band imaging for the diagnosis of depth of invasion by Japan Esophageal Society (JES) classification and inter- and intraobserver agreement of JES intrapapillary capillary loop (IPCL) classification. METHODS: It was a retrospective observational study that has analyzed 136 patients with esophageal malignant neoplasia with magnifying endoscopy narrow band imaging to compare JES's IPCL classification to the histopathologic findings and to evaluate the inter- and intraobserver agreement. RESULTS: Histopathologic examinations revealed 34 (25.7%) intraepithelial neoplasias, 70 (51.5%) squamous cell carcinomas (SCCs) in the epithelium or with invasion into the lamina propria mucosa, 21 (15.4%) SCCs with invasion into the muscularis mucosa or mild invasion into the submucosa, and 11 (8.1%) SCCs with moderate or deep invasion into the submucosa. IPCL types B1, B2, and B3 also showed high accuracies of 80.8, 83.1, and 94.1%, respectively. The kappa values for inter- and intraobserver agreements of the IPCL classifications were moderate to almost perfect. CONCLUSIONS: In the present study, the JES's IPCL classification has good accuracy to predict the depth of SCC invasion and moderate to almost perfect intra- and interobserver agreements.

Interobserver and intraobserver agreement for gastric mucosa atrophy.

BACKGROUND: The grade of gastric mucosa atrophy caused by Helicobacter pylori (H. pylori) infection is closely associated with the risk of gastric cancer, especially of the intestinal type. Interobserver and intraobserver agreement for endoscopic gastric mucosa atrophy in subjects with H. pylori-uninfected, currently infected and past infected was investigated. METHODS: Endoscopic images of 91 patients, 34 images per patient, were assessed. The assessors were 4 endoscopist groups: Japanese and Vietnamese experienced (≥7, ≤ 15 year experience with endoscopy) and Japanese and Vietnamese beginner (≤ 3 year experience) groups. Each group comprised 3 endoscopists. The grades of atrophy were classified as 3: none to mild (C-0 and C-1), moderate (C-2 and C-3), and severe (O-1, O-2, and O-3) using the Kimura-Takemoto Classification. After a period of 2 weeks, images of all patients were reevaluated by the investigators. Interobserver and intraobserver agreement was calculated by kappa statistics. RESULTS: The kappa values for the interobserver agreement in the groups of Japanese and Vietnamese experienced, and Japanese and Vietnamese beginner were 0.474, 0.408, 0.291, and 0.373, respectively. The kappa value of intraobsever agreement in the Japanese and Vietnamese experienced endoscoists ranged from 0.585 to 0.871. On the other hand, the value in the beginner endoscopists ranged wider than that in experienced endoscopists, from 0.264 to 0.866. CONCLUSIONS: Our results indicated that, although intraobserver agreement for gastric mucosa atrophy was good to excellent, interobserver agreement was moderate in experienced endoscopists. This suggests that better guidelines and firm criteria may be needed to properly diagnose and grade gastric atrophy.

Differences in K-ras and mitochondrial DNA mutations and microsatellite instability between colorectal cancers of Vietnamese and Japanese patients.

BACKGROUND: The incidence of early-onset (under 50 years of age) colorectal cancer (CRC) in the Vietnamese has been reported to be quite higher than that in the Japanese. To clarify the differences in genetic alterations between Vietnamese and Japanese CRCs, we investigated mutations in K-ras and mitochondrial DNA (mtDNA) and high-frequency microsatellite instability (MSI-H) in the CRCs of Vietnamese and Japanese patients. METHODS: We enrolled 60 Vietnamese and 233 Japanese patients with invasive CRCs. DNA was extracted from formalin-fixed, paraffin-embedded tissue sections. K-ras mutations were examined with PCR-single-strand conformation polymorphism analysis. mtDNA mutations and MSI-H were examined with microsatellite analysis using D310 and BAT-26, respectively. RESULTS: K-ras mutations were examined in 60 Vietnamese and 45 Japanese CRCs. The frequency of the mutations in the Vietnamese CRCs was significantly higher than that in the Japanese CRCs (8 of 24 [33%] vs 5 of 45 [11%], p =0.048). MSI-H was examined in 60 Vietnamese and 130 Japanese CRCs. The frequency of MSI-H in the Vietnamese CRCs was also significantly higher than that in the Japanese CRCs (6 of 27 [22%] vs 10 of 130 [8%], p =0.030). mtDNA mutations were examined in 60 Vietnamese and 138 Japanese CRCs. The frequency of mtDNA mutations in the Vietnamese CRCs was significantly higher than that in the Japanese CRCs (19 of 44 [43%] vs 11 of 133 [9%], p <0.001). There were no significant differences in clinicopathologic characteristics, such as age, sex, tumour location, and depth, in terms of tumours with/without each genetic alteration in the CRCs of the Vietnamese and Japanese patients. CONCLUSIONS: These results indicate that the developmental pathways of CRCs in the Vietnamese may differ from those of CRCs in the Japanese.