Obesity and Upper Gastrointestinal Diseases.

Obesity increases gastroesophageal reflux disease through several factors. As a result, Barrett's esophagus, esophageal adenocarcinoma, and gastroesophageal junctional gastric cancer are increasing. Existing studies usually defined obesity by body mass index and analyzed the correlation. Recently, more studies have shown that central obesity is a more important variable in upper gastrointestinal diseases related to gastroesophageal reflux. Studies have reported that weight loss is effective in reducing gastroesophageal reflux symptoms. Obesity also affects functional gastrointestinal diseases. A significant correlation was shown in upper abdominal pain, reflux, vomiting, and diarrhea rather than lower abdominal diseases.

Factors influencing occurrence of metachronous gastric cancer after endoscopic resection: a systematic review and meta-analysis.

BACKGROUND/AIMS: Metachronous gastric cancer (MGC) can occur after endoscopic resection for gastric cancer. Further studies on factors other than Helicobacter pylori infection are needed. This systematic review and meta-analysis aimed to evaluate risk factors for metachronous recurrence of endoscopically resected gastric cancer. METHODS: We searched medical literature published by February 2023 and identified patients with MGC after endoscopic resection for gastric cancer. The occurrence of MGC and the presence of intestinal metaplasia (IM), severe atrophic gastritis (AG), and H. pylori infection were quantitatively analyzed. RESULTS: We identified 2,755 patients from nine cohort studies who underwent endoscopic resection for gastric cancer by 2018. Those with severe AG or presence of IM had a significantly higher incidence of MGC than those without (RR 2.00, 95% CI 1.35-2.98, I2 = 52% for severe atrophy on antrum; RR 7.08, 95% CI 3.63-13.80, I2 = 0% for antral IM). Absolute risk difference of MGC occurrence was 7.1% in those with severe AG and 9.2% in those with IM. The difference in incidence rate per 1,000 person-years was 17.5 person-years for those with severe AG and 24.7 person-years for those with IM. However, H. pylori eradication did not significantly affect the occurrence of MGC (RR 1.18, 95% CI 0.88-1.59, I2 = 10%). CONCLUSION: Gastric cancer patients with severe AG or presence of IM had a 2.0-fold or 7.0-fold higher risk of MGC occurrence after endoscopic resection than those without, respectively. They need more stringent follow-up to monitor MGC occurrences (CRD42023410940).

Prevalence, natural progression, and clinical practices of upper gastrointestinal subepithelial lesions in Korea: a multicenter study.

BACKGROUND/AIMS: This study aimed to evaluate the prevalence and natural progression of subepithelial lesions (SELs) in the upper gastrointestinal (UGI) tract. METHODS: The medical records of patients with UGI SELs who underwent endoscopic screening at eight university hospitals between January and December 2010 were retrospectively investigated. The follow-up evaluations were performed until December 2016. RESULTS: UGI SELs were found in 1,044 of the 65,233 participants screened (endoscopic prevalence, 1.60%; the total number of lesions, 1,062; mean age, 55.1±11.2 years; men, 53.6%). The median follow-up period was 48 (range, 8-74) months. SELs were most frequently found in the stomach (63.8%) and had a mean size of 9.9±6.1 mm. Endoscopic ultrasonography (EUS) was performed in 293 patients (28.1%). The most common lesions were leiomyomas, followed by gastrointestinal stromal tumors (GISTs), and ectopic pancreas. The proportions of SELs with malignant potential according to size were 3% (<1 cm), 22% (1-2 cm), 27% (2-3 cm), and 38% (≥3 cm). In gastric SELs larger than 1 cm, resections were performed in 20 patients because of an increase in size, of which 12 were found to be GISTs. CONCLUSION: The prevalence of UGI SELs was 1.60%. Further, 23% of gastric SELs ≥1 cm were precancerous lesions, most followed by EUS and clinical decisions without initial pathological confirmation.

The optimal interval of surveillance gastroscopy after endoscopic resection for gastric neoplasia: a multicenter cohort study.

BACKGROUND/AIMS: Due to the possible metachronous recurrence of gastric neoplasia, surveillance gastroscopy is mandatory after endoscopic resection for gastric neoplasia. However, there is no consensus on the surveillance gastroscopy interval. This study aimed to find an optimal interval of surveillance gastroscopy and to investigate the risk factors for metachronous gastric neoplasia. METHODS: Medical records were reviewed retrospectively in patients who underwent endoscopic resection for gastric neoplasia in 3 teaching hospitals from June 2012 to July 2022. Patients were divided into two groups; annual surveillance vs. biannual surveillance. The incidence of metachronous gastric neoplasia was identified, and the risk factors for metachronous gastric neoplasia were investigated. RESULTS: Among the 1,533 patients who underwent endoscopic resection for gastric neoplasia, 677 patients were enrolled in this study (annual surveillance 302, biannual surveillance 375). Metachronous gastric neoplasia was observed in 61 patients (annual surveillance 26/302, biannual surveillance 32/375, P = 0.989), and metachronous gastric adenocarcinoma was observed in 26 patients (annual surveillance 13/302, biannual surveillance 13/375, P = 0.582). All the lesions were removed by endoscopic resection successfully. In a multivariate analysis, severe atrophic gastritis on gastroscopy was an independent risk factor for metachronous gastric adenocarcinoma (odds ratio 3.8, 95% confidence interval 1.4‒10.1; P = 0.008). CONCLUSIONS: Meticulous observation to detect the metachronous gastric neoplasia is necessary for patients with severe atrophic gastritis during follow-up gastroscopy after endoscopic resection for gastric neoplasia. Annual surveillance gastroscopy might be enough after endoscopic resection for gastric neoplasia.

Effective Eradication Regimen and Duration According to the Clarithromycin Susceptibility of Helicobacter pylori Determined Using Dual Priming Oligonucleotide-Based Multiplex Polymerase Chain Reaction.

Background/Aims: Dual priming oligonucleotide-based multiplex polymerase chain reaction (DPO-PCR) has recently been used for both the detection of Helicobacter pylori and the identification of H. pylori 23S ribosomal RNA point mutations that cause clarithromycin resistance. The aim of this study was to investigate the duration of effective standard triple therapy in a clarithromycin susceptible group and of bismuth-based quadruple therapy in a resistant group based on DPO-PCR. Methods: We retrospectively analyzed the electronic medical records of 184 patients who, between September 2019 and December 2020, received eradication therapy following detection of H. pylori, and the subsequent identification of the clarithromycin susceptibility of their H. pylori using DPO-PCR. Patients were treated with 7- or 14-day standard triple therapy in the clarithromycin susceptible group, whereas 7- or 14-day bismuth-based quadruple therapy in the clarithromycin resistance group. Results: In the clarithromycin susceptible group, per-protocol analyses showed eradication rates of 87.5% (42/48; 95% confidence interval [CI], 77.1% to 95.8%) for 7-day therapy and 87.2% (41/47; 95% CI, 78.7% to 95.7%) for 14-day therapy (p=0.969). The eradication rates in the clarithromycin resistance group were 91.4% (32/35; 95% CI, 80.0% to 100.0%) for 7-day therapy and 90.3% (28/31; 95% CI, 77.4% to 100.0%) for 14-day therapy (p=0.876). There was no significant difference in the eradication rates, patient compliance, or rate of adverse events between the 7- and 14-day therapies for both groups. Conclusions: Compared to the 14-day therapy, 7-day eradication therapy is sufficient after DPO-PCR-based clarithromycin susceptibility testing.

The Influence of Past Metronidazole Exposure on the Outcome of Helicobacter pylori Eradication.

Background: Bismuth quadruple therapy (BQT) is recommended as empirical first-line therapy because it is not affected by antibiotic resistance. We examined whether past exposure to metronidazole affected BQT outcomes. Methods: The records of seven hospitals were searched for patients who received BQT for Helicobacter pylori eradication between 2009 and 2020. The association between past metronidazole exposure and the eradication rate was evaluated. Results: This study was a multicenter retrospective study. Around 37,602 people tested for H. pylori infection were identified, and 7,233 received BQT. About 2,802 (38.7%) underwent a 13C-urea breath test to confirm eradication. The BQT efficacy was 86.4% among patients without metronidazole exposure and 72.8% among patients with exposure (p < 0.001). The eradication rate of BQT 14 days in patients with past exposure was higher than that of BQT <14 days (85.5 vs. 66.0%, p = 0.009). Multivariate analysis revealed that past metronidazole exposure [odds ratio (OR) 2.6, 95% CI 1.8-3.7; p < 0.001] and BQT <14 days (OR 1.5, 95% CI 1.2-2.0; p = 0.002) were independent risk factors for eradication failure. Conclusion: Past metronidazole exposure significantly lowered the BQT eradication rate. BQT 14 days should be recommended for patients with suspected metronidazole exposure.

Types of 23S Ribosomal RNA Point Mutations and Therapeutic Outcomes for Helicobacter pylori.

Background/Aims: Point mutations in the 23S ribosomal RNA gene have been associated with Helicobacter pylori clarithromycin resistance. This study aimed to detect the prevalence of these point mutations and to investigate the role of different point mutations in the success of eradication therapy. Methods: We retrospectively investigated a total of 464 consecutive patients who underwent an endoscopic examination and dual-priming oligonucleotide-based multiplex polymerase chain reaction for H. pylori between June 2014 and October 2019. For 289 patients with negative point mutations, standard triple therapy was used in 287 patients, and the bismuth-quadruple regimen was used in two patients. For 175 patients with positive point mutations (A2142G, A2143G, and both mutations), standard triple and bismuth-quadruple therapies were used in 37 patients and 138 patients, respectively. Results: The eradication rates of standard triple and bismuth-quadruple therapies showed no significant difference in mutation-negative patients or those with the A2142G point mutation. However, the eradication rate with bismuth-quadruple therapy was significantly higher than that with standard triple therapy in the group with the A2143G mutation or with the double mutation. The eradication rates for standard triple and bismuth-quadruple therapies, respectively, were 25.8% and 92.1% in the per-protocol group (p<0.001) and 24.2% and 85.2% in the intention-totreat analysis (p<0.001). Conclusions: The A2143G point mutation is the most prevalent cause of clarithromycin resistance. Bismuth-quadruple therapy is superior to standard triple therapy in patients with the A2143G or double point mutation.

Implementation effect of institutional policy of EGD observation time on neoplasm detection.

BACKGROUND AND AIMS: The observation time in EGD is associated with detection rate of premalignant or neoplastic lesions in the upper GI (UGI) tract. The aim of this study was to evaluate an institutional policy of EGD observation time on the detection rate of UGI neoplasms. METHODS: From July 2017 to March 2019, all endoscopists were requested to comply with our institutional policy of spending more than 3 minutes of observation time in every screening EGD. Observation time was defined as the time from when the endoscope reached the duodenum to when it was withdrawn. We obtained a neoplasm detection rate (NDR) during this period and compared it with that of a baseline period from 2009 to 2015. RESULTS: During the study period, 30,506 EGDs were performed. Mean subject age was 49.9 ± 10.5 years, and 56.5% were men. All endoscopists achieved an average EGD observation time of more than 3 minutes during this period. Mean observation time was 3:35 ± 0:50, which was significantly longer than the baseline (2:38 ± 0:21, P < .001). NDR was .33%, which was higher than the baseline (.23%, P < .001). Even after adjusting for subjects' age and gender, smoking history, and endoscopists' biopsy sampling rate, prolonged EGD observation time of more than 3 minutes increased the NDR of UGI neoplasms (odds ratio, 1.51; 95% confidence interval, 1.21-1.75). CONCLUSIONS: This study provides evidence that implementing a protocol of a prolonged observation time could increase NDR. Observation time should be an important quality indicator of the EGD examination.

A Dodecapeptide Selected by Phage Display as a Potential Theranostic Probe for Colon Cancers.

AIM: Colon cancer is one of the leading causes of cancer-related mortality. However, specific biomarkers for its diagnosis or treatment are not established well. METHODS: We developed a colon-cancer specific peptide probe using phage display libraries. We validated the specificity of this probe to colon cancer cells with immunohistochemical staining and FACS analysis using one normal cell and five colon cancer cell lines. RESULTS: This peptide probe maintained binding affinity even after serum incubation. For therapeutic applications, this peptide probe was conjugated to hematoporphyrin, a photosensitizer, which showed a significantly enhanced cellular uptake and high photodynamic effect to kill tumor cells. As another application, we made a nanoparticle modified from the peptide probe. It efficiently delivered SN-38, an anticancer drug, into tumor cells, and its tumor-targeting ability was observed in vivo after intravenous injection to the same xenograft model. CONCLUSION: The noble dodecapeptide probe can be a promising candidate for both colon tumor diagnosis and targeted drug delivery.