Implementing narrow banding imaging with dual focus magnification for histological prediction of small rectosigmoid polyps in Vietnamese setting.

Background and Aim: Small rectosigmoid colorectal polyps (<10 mm) are prevalent, with a low prevalence of advanced neoplastic lesions. The "diagnose-and-leave" strategy, employing narrow band imaging (NBI), is gaining popularity for its safety and cost-effectiveness by reducing polypectomy complications and minimizing histopathology expenses. This study assessed the diagnostic efficacy of NBI with dual focus (DF) magnification for real-time neoplastic prediction of rectosigmoid polyps and explored the feasibility of implementing this strategy in Vietnam. Methods: In a prospective single-center study, 307 rectosigmoid polyps from 245 patients were analyzed using three consecutive endoscopic modes: white light endoscopy (WLE), NBI, and NBI-DF. Endoscopists assessed polyps for size, location, macroscopic shape, optical diagnosis, and confidence levels before histopathological evaluation. High confidence was assigned when the polyp exhibited all features of a single histology type. Predictions were compared with final histopathology results. Results: Of the total, 237 (77.2%) were diminutive (≤5 mm) polyps, and 18 (5.8%) were advanced neoplastic lesions. WLE + NBI and WLE + NBI + NBI-DF exhibited significantly higher accuracy compared to WLE (88.6% and 90.2% vs 74.2%, P < 0.01). For diminutive polyps, the DF mode significantly increased the rate of high-confidence optical diagnoses (89.1% vs 94.9%, P < 0.001). WLE + NBI + NBI-DF demonstrated high sensitivity (90.1%), specificity (95.5%), and negative predictive value (93.4%) in high-confidence predictions, enabling the implementation of the "diagnose-and-leave" strategy. This approach would have reduced 58.2% of unnecessary polypectomies without missing any advanced neoplastic lesions. Conclusion: NBI and DF modes provide accurate neoplastic predictions for rectosigmoid polyps. For diminutive polyps, DF magnification improves the confidence level of the optical diagnosis, allowing the safe implementation of the "diagnose-and-leave" strategy.

Prevalence, risk factors, and BRAF mutation of colorectal sessile serrated lesions among Vietnamese patients.

BACKGROUND: Sessile serrated lesions (SSLs) are considered precancerous colorectal lesions that should be detected and removed to prevent colorectal cancer. Previous studies in Vietnam mainly investigated the adenoma pathway, with limited data on the serrated pathway. AIM: To evaluate the prevalence, risk factors, and BRAF mutations of SSLs in the Vietnamese population. METHODS: This is a cross-sectional study conducted on patients with lower gastrointestinal symptoms who underwent colonoscopy at a tertiary hospital in Vietnam. SSLs were diagnosed on histopathology according to the 2019 World Health Organization classification. BRAF mutation analysis was performed using the Sanger DNA sequencing method. The multivariate logistic regression model was used to determine SSL-associated factors. RESULTS: There were 2489 patients, with a mean age of 52.1 ± 13.1 and a female-to-male ratio of 1:1.1. The prevalence of SSLs was 4.2% [95% confidence interval (CI): 3.5-5.1]. In the multivariate analysis, factors significantly associated with SSLs were age ≥ 40 [odds ratio (OR): 3.303; 95%CI: 1.607-6.790], male sex (OR: 2.032; 95%CI: 1.204-3.429), diabetes mellitus (OR: 2.721; 95%CI: 1.551-4.772), and hypertension (OR: 1.650, 95%CI: 1.045-2.605). The rate of BRAF mutations in SSLs was 35.5%. CONCLUSION: The prevalence of SSLs was 4.2%. BRAF mutations were present in one-third of SSLs. Significant risk factors for SSLs included age ≥ 40, male sex, diabetes mellitus, and hypertension.

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.

Utility of narrow-band imaging with or without dual focus magnification in neoplastic prediction of small colorectal polyps: a Vietnamese experience.

BACKGROUND/AIMS: Accurate neoplastic prediction can significantly decrease costs associated with pathology and unnecessary colorectal polypectomies. Narrow band imaging (NBI) and dual-focus (DF) mode are promising emerging optical technologies for recognizing neoplastic features of colorectal polyps digitally. This study aimed to clarify the clinical usefulness of NBI with and without DF assistance in the neoplastic prediction of small colorectal polyps (<10 mm). METHODS: This cross-sectional study included 530 small colorectal polyps from 343 consecutive patients who underwent colonoscopy at the University Medical Center from September 2020 to May 2021. Each polyp was endoscopically diagnosed in three successive steps using white-light endoscopy (WLE), NBI, and NBI-DF and retrieved for histopathological assessment. The diagnostic accuracy of each modality was evaluated with reference to histopathology. RESULTS: There were 295 neoplastic polyps and 235 non-neoplastic polyps. The overall accuracies of WLE, WLE+NBI, and WLE+NBI+NBI-DF in the neoplastic prediction of colorectal polyps were 70.8%, 87.4%, and 90.8%, respectively (p<0.001). The accuracy of WLE+NBI+NBI-DF was significantly higher than that of WLE+NBI in the polyp size ≤5 mm subgroup (87.3% vs. 90.1%, p<0.001). CONCLUSION: NBI improved the real-time neoplastic prediction of small colorectal polyps. The DF mode was especially useful in polyps ≤5 mm in size.

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.

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.

The Distribution of Incomplete Gastric Intestinal Metaplasia (GIM) Subtype among Biopsy Sites according to the Updated Sydney System and Its Association with GIM Extension.

BACKGROUND: Current guidelines recommend that extensive gastric intestinal metaplasia (GIM) be considered as a high-risk marker for the development of gastric cancer (GC). But there is emerging evidence that the incomplete GIM subtype is also a high-risk marker. AIMS: To evaluate the performance of biopsy sites according to the updated Sydney system on detecting the incomplete GIM subtype and to assess its association with GIM extension. PATIENTS AND METHODS: A cross-sectional study was conducted on 280 Vietnamese patients with nonulcer dyspepsia. Biopsy specimens were taken from gastric sites according to the updated Sydney system, and sections were routinely stained with Giemsa and hematoxylin and eosin. Biopsy specimens with intestinalization were further evaluated for GIM subtypes with alcian blue 2.5 and periodic acid Schiff stainings. Two experienced pathologists jointly examined all the specimens and reached consensus. RESULTS: The rates of patients with GIM and the incomplete GIM subtype were 81 (28.9%) and 24 (8.4%), respectively. There was no GIM in specimens taken from the greater curvature of corpus. The proportions of the incomplete GIM subtype detected at the incisura angularis, lesser curvature of corpus, lesser curvature of antrum, and greater curvature of antrum were 34.3% (12/35), 34.5% (10/29), 40.5% (17/42), and 31.6 (6/19), respectively, which were not significantly different (p = 0.89). The presence of an incomplete GIM subtype was associated with multifocal GIM (i.e., ≥3 out of 5 biopsy sites with GIM) (OR = 4.02, CI 95%, 1.33-12.16, p = 0.022) and extensive GIM (i.e., GIM in specimens from both of corpus and antrum) (OR = 2.89, CI 95% 1.04-8.02, p = 0.045). CONCLUSIONS: The proportions of an incomplete GIM subtype were not significantly different among gastric biopsy sites with intestinalization. The association between an incomplete GIM subtype and GIM extension, therefore, may be due to an sum accumulation effect.

Comparison of the Treatment Efficiency of Bone Marrow-Derived Mesenchymal Stem Cell Transplantation via Tail and Portal Veins in CCl4-Induced Mouse Liver Fibrosis.

Because of self-renewal, strong proliferation in vitro, abundant sources for isolation, and a high differentiation capacity, mesenchymal stem cells are suggested to be potentially therapeutic for liver fibrosis/cirrhosis. In this study, we evaluated the treatment effects of mouse bone marrow-derived mesenchymal stem cells (BM-MSCs) on mouse liver cirrhosis induced by carbon tetrachloride. Portal and tail vein transplantations were examined to evaluate the effects of different injection routes on the liver cirrhosis model at 21 days after transplantation. BM-MSCs transplantation reduced aspartate aminotransferase/alanine aminotransferase levels at 21 days after injection. Furthermore, BM-MSCs induced positive changes in serum bilirubin and albumin and downregulated expression of integrins (600- to 7000-fold), transforming growth factor, and procollagen-α1 compared with the control group. Interestingly, both injection routes ameliorated inflammation and liver cirrhosis scores. All mice in treatment groups had reduced inflammation scores and no cirrhosis. In conclusion, transplantation of BM-MSCs via tail or portal veins ameliorates liver cirrhosis in mice. Notably, there were no differences in treatment effects between tail and portal vein administrations. In consideration of safety, we suggest transfusion of bone marrow-derived mesenchymal stem cells via a peripheral vein as a potential method for liver fibrosis treatment.

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.

Relationship between endoscopic and histologic gastric atrophy and intestinal metaplasia.

BACKGROUND: The severity of endoscopic gastric atrophy (EGA), high-stage Operative Link on Gastritis Assessment (OLGA) gastritis (i.e., stage III or IV), and extensive intestinal metaplasia (IM) with incomplete subtype have been separately reported as high-risk factors of gastric cancer (GC). The aim of this study was to evaluate the associations between these endoscopic and pathologic characteristics. MATERIALS AND METHODS: A cross-sectional study was conducted on 280 patients with functional dyspepsia at the University Medical Center at Ho Chi Minh City, Vietnam. Biopsies were taken according to the updated Sydney System. EGA was assessed according to the Kimura-Takemoto classification, and gastritis stage was assessed according to the OLGA system. RESULTS: All of patients with high-stage OLGA gastritis (i.e., stage III or IV) clustered in the subgroup of patients with moderate-to-severe EGA: 13/126 (10.3%) in patients with moderate-to-severe EGA versus 0/154 (0%) in patients with none-to-mild EGA (p < .001). Moderate-to-severe EGA was also significantly associated with extensive IM (p < .001, OR = 28.1 (CI 95% 6.4-173.3)) and incomplete IM subtype (p < .001, OR = 36.7 (CI 95% 5.1-742.1). Extensive IM was also associated with incomplete IM subtype (p = .01). CONCLUSIONS: High-stage OLGA gastritis, extensive IM with incomplete subtype clustered in patients with moderate-to-severe EGA. Assessing the severity of EGA could potentially help to identify patients who should be taken systemic biopsy for evaluating GC risk.

The severity of endoscopic gastric atrophy could help to predict Operative Link on Gastritis Assessment gastritis stage.

BACKGROUND AND AIMS: The aims of the present study were to evaluate the role of moderate-to-severe endoscopic gastric atrophy (EGA) on predicting Operative Link on Gastritis Assessment (OLGA) gastritis stage, and to assess the association of high-stage OLGA gastritis with gastric neoplasia in patients with non-ulcer dyspepsia. METHODS: A cross-sectional study was carried out on 280 dyspeptic outpatients. EGA was assessed according to the Kimura-Takemoto classification. Gastritis stage was established according to the OLGA staging system and gastric neoplasia was assessed according to the Vienna classification. The pathologists who read the specimens were kept blind to the endoscopic results. RESULTS: The mean age of patients was 46.1 years (range 20-78 years) with a male-to-female ratio of 1:1. High-stage gastritis (e.g. stage III or IV) was confirmed in 13 (4.6%) patients. All of these patients were more than 40 years-of-age (P = 0.01), had Helicobacter pylori infection (P = 0.0006) and moderate-to-severe EGA (P < 0.001). Low-grade dysplasia was found in seven patients: 4/13 (30.7%) with high-stage gastritis versus 3/267 (1.1%) with low-stage gastritis (P < 0.001). Six of these patients had moderate-to-severe EGA (P = 0.048). The sensitivity, specificity, positive predictive value and negative predictive value of this endoscopic finding in high-stage gastritis diagnosis were 100%, 57.7%, 10.3% and 100%, respectively. CONCLUSIONS: OLGA high-stage gastritis was associated with gastric dysplasia and was mostly diagnosed in patients with moderate-to-severe EGA. The absence of this endoscopic finding could effectively rule out the possibility of having high-stage gastritis.