Gastric Cancer Incidence and Mortality After Endoscopic Resection of Gastric Adenoma: A Nationwide Cohort Study.

INTRODUCTION: Gastric adenoma is a precursor lesion of gastric cancer. We investigated whether the removal of gastric adenoma prevented gastric cancer incidence and its mortality. METHODS: Using the linkage of nationwide databases, we assessed gastric cancer incidence and mortality among patients who had gastric adenomas removed between 2011 and 2013 in Korea. These outcomes were compared primarily with those of the Korean general population by estimating the standardized incidence and mortality ratio and secondarily with internal control subjects who did not have gastric neoplasm after esophagogastroduodenoscopy and were matched for age, sex, and calendar year by calculating hazard ratios (HR) with the Cox proportional hazards model. RESULTS: We identified 44,405 adenoma removal patients. During a median follow-up of 8.4 years, 1,038 (2.34%) of them were given a diagnosis of gastric cancer and a total of 524 gastric cancers were expected for a standard incidence ratio of 1.98 (95% confidence interval [CI], 1.84-2.13). A total of 199 deaths from gastric cancer were expected and 99 were observed for a standard mortality ratio of 0.50 (95% CI, 0.40-0.60). Compared with the nonadenoma cohort (n = 39,826), the adenoma removal patients had a higher risk of gastric cancer (HR, 2.84; 95% CI, 2.51-3.21) and associated mortality (HR, 1.66; 95% CI, 1.19-2.31). DISCUSSION: Removal of gastric adenoma resulted in lower-than-expected mortality but higher-than-expected incidence due to gastric cancer than that in the general population. Our analyses indicated the importance of follow-up strategy after removal of gastric adenoma.

Accuracy of administrative claim data for gastric adenoma after endoscopic resection.

BACKGROUND/AIMS: Administrative databases provide valuable information for large-cohort studies. This study aimed to evaluate the diagnostic accuracy of an administrative database for resected gastric adenomas. METHODS: Data of patients who underwent endoscopic resection for benign gastric lesions were collected from three hospitals. Gastric adenoma cases were identified in the hospital database using International Classification of Diseases (ICD) 10-codes. The non-adenoma group included patients without gastric adenoma codes. The diagnostic accuracy for gastric adenoma was analyzed based on the pathological reports of the resected specimen. RESULTS: Among 5,095 endoscopic resections with codes for benign gastric lesions, 3,909 patients were included in the analysis. Among them, 2,831 and 1,078 patients were allocated to the adenoma and non-adenoma groups, respectively. Regarding the overall diagnosis of gastric adenoma with ICD-10 codes, the sensitivity, specificity, positive predictive value, and negative predictive value were 98.7%, 88.5%, 95.2%, and 96.8%, respectively. There were no significant differences in these parameters between the tertiary and secondary centers. CONCLUSION: Administrative codes of gastric adenoma, according to ICD-10 codes, showed good accuracy and can serve as a useful tool to study prognosis of these patients in real-world data studies in the future.

Tumor heterogeneity and carcinoma in resected specimens of gastric low-grade dysplasia: A retrospective single center study.

Lesions diagnosed as gastric low-grade dysplasia (LGD) may be pathologically upgraded to early gastric cancer (EGC) or high-grade dysplasia (HGD) after endoscopic resection (ER). In this study, we investigated the risk factors for pathological upgrades after ER and assessed the reason for these upgrades by retrospectively analyzing ER data between January 1999 and December 2019. We enrolled patients with LGD confirmed by forceps biopsy; the patients were classified into pathologically concordant (LGD) and upgraded (HGD and EGC) groups according to the pathology of their resected specimen. To determine the risk factors for upgrade, we compared the endoscopic findings of the concordant and upgraded groups via 1:1 matched case-control design. To find the reasons for discordance, all upgraded cases were pathologically re-evaluated. Among 1,643 cases of LGD, pathological upgrades were observed in 423 (25.7%) resected specimens and EGC was found in 111 (6.7%) lesions. After matching the upgraded and concordant cases, lesion sizes exceeding 1.5 cm (odds ratio (OR): 1.8; 95% CI: 1.1-3.0), mucosal nodularity (OR: 10.8; 95% CI: 5.6-21.0), heterogeneous color (OR: 3.0; 95% CI: 1.7-5.3), presence of erosion (OR: 2.7; 95% CI: 1.8-5.3), and open-type gastric atrophy (OR: 2.9; 95% CI: 1.7-4.9) were noted to be significantly associated with upgraded pathology to EGC. Among the EGC cases, 99 (89.2%) were found to have pre-existing dysplasia. In conclusion, endoscopic evaluations should be performed because of possible pathological upgrades and co-existence of carcinomas in LGDs, especially when they exhibit surface nodularity, erosion, heterogeneous color, and large size.

Efficacy of bougie dilation for normal diet in benign esophageal stricture.

OBJECTIVES: Bougination is one of the first-line treatments in benign esophageal stricture (BES). The aim of the study was to identify clinical and endoscopic factors affecting the achievement of a normal diet with only bougie dilation in patients with BES. PATIENTS AND METHODS: Patients treated with only bougination for BES at three hospitals were retrospectively investigated. Data including patient demographics, stricture and procedural characteristics were collected. Clinical success was defined as normal diet without additional procedures for two months after bougination. Clinical success rate and associated factors were assessed. RESULTS: A total of 121 patients with BES were included. The most common cause of BES was post-operative stricture (n = 55). Finally, 43 (36%) patients were able to eat a normal diet with only bougination. Of these patients, 42 (97.7%) achieved clinical success in the first three sessions or less. Among causes of stenosis, corrosive injury had the lowest success rate (9/40, 22.5%). Clinical success rate was significantly higher for those with the length of stricture of less than 2 cm (47.2%), those with pre-procedural dysphagia of semi-solid or soft diet (51.3%) and those with dilation of 13 mm or more (46.1%). However, the duration of symptom, the number of previous endoscopic treatments and the location of stenosis were not related to clinical success. CONCLUSIONS: Normal diet is possible in one-third of BES after bougination alone. Predictable factors for achieving a normal diet were less than four sessions of dilation, short length of stricture, pre-procedural dysphagia status and diameter of dilator.

Combined high NEDD9 expression and E-cadherin loss correlate with poor clinical outcome in gastric cancer.

BACKGROUND AND AIM: Neural precursor cell expressed developmentally downregulated 9 (NEDD9) is a member of the Cas family. Previous studies have revealed that NEDD9 coordinates the focal adhesion kinase and Src signaling cascades that are involved in integrin-dependent adhesion and migration, invasion, cell apoptosis and life cycle, and survival, which may play a role in epithelial-mesenchymal transformation. The aim of this study was to analyze the expression of NEDD9 and E-cadherin in gastric cancer (GC) and evaluate their clinical significance. METHODS: NEDD9 and E-cadherin expression was analyzed with immunohistochemistry using tissue microarray technique in 435 GC patients who underwent gastrectomy. The NEDD9 expression level was defined by the combination score, which was determined by multiplying the staining intensity score and the proportion score (≥5; NEDD9-high, <5; NEDD9-low). E-cadherin loss was defined as a total loss of staining. The clinicopathologic parameters, overall survival, and disease-free survival rates were analyzed according to the NEDD9 and E-cadherin expression status. RESULTS: The combined NEDD9 and E-cadherin expression status correlated with lymphatic invasion (P = 0.001), vascular invasion (P = 0.020), and T stage (P = 0.001). Combined high NEDD9 expression and loss of E-cadherin expression status had a worse overall survival rate (P < 0.001) and served as a poor prognostic factor (Hazard ratio 2.49, 95% CI 1.25-5, P = 0.01). CONCLUSIONS: Immunohistochemical staining for NEDD9 and E-cadherin may function as a candidate prognostic marker for gastric cancer in everyday practice, especially when applied in combination.

Infectious events after endoscopic procedures in patients with neutropenia and hematologic diseases.

BACKGROUND: Few studies evaluated the post-endoscopic adverse events in patients with neutropenia. We investigated the development of infectious events after endoscopic procedures in neutropenic patients with hematologic diseases. METHODS: Patients with neutropenia and hematologic diseases who underwent endoscopic procedures were enrolled. Neutropenia was defined as an absolute neutrophil count < 1500 cells/mm3 and its severity was subdivided as mild, moderate (< 1000 cells/mm3), and severe (< 500 cells/mm3). Infectious events were defined as fever or bacteremia within 7 days after endoscopy. We assessed the development and risk factors of infectious events after endoscopic procedures. RESULTS: We identified 528 procedures in 479 patients (51.0 ± 1.0 years). Antibiotics were used in 455 (95.0%) cases within 3 days of endoscopy. Infectious events were observed in 154 patients (32.2%): 22.9% in mild, 29.5% in moderate, and 43.1% in severe neutropenia. Fever developed in 147 cases (30.7%). Among patients with blood culture studies (n = 267), bacteremia was found in 22 cases (8.2%). In univariate analysis, patients with myelodysplastic syndrome, poor performance status, severe neutropenia, non-use of immunosuppressive drugs, and without history of hematopoietic stem cell transplantation and colony-stimulating factor use were positively correlated with infectious events. Poor performance status was the strongest factor for the development of infectious events in multivariate analysis (OR 10.3; 95% CI 4.4-23.3; P < 0.01). CONCLUSIONS: Procedural invasiveness and severity of neutropenia did not appear to affect infectious events after endoscopic procedure with the use of antibiotics. Neutropenic patients who have poor performance status require careful evaluation for appropriate indications of endoscopic evaluation.

Use of Proton Pump Inhibitors vs Histamine 2 Receptor Antagonists for the Risk of Gastric Cancer: Population-Based Cohort Study.

INTRODUCTION: Proton pump inhibitors (PPIs) are commonly prescribed medications. Long-term use of PPIs has been suspected to have a provocative effect on gastric cancer. This study was to determine the association between PPI vs histamine 2 receptor antagonist (H2RA) use and the risk of gastric cancer in a region where the risk of this malignancy is high. METHODS: A population-based cohort study using the Korean National Health Insurance Services Database. The participants with first prescription of PPIs and H2RA with normal esophagogastroduodenoscopy finding from 2004 through 2015 were collected. Among them, 50% of participants were systematic stratified randomly sampled. There were 122,118 users of PPIs or H2RAs who use medication more than cumulative defined daily dose of 180 days. The users were followed up from long-term use threshold until gastric cancer, death from non-gastric cancer cause, gastric surgery, or study end (December 2017). RESULTS: After calculating propensity score weights, we included 39,799 PPI and 38,967 H2RA users. Among the new PPI and H2RA users, we identified 411 cases of incident gastric cancer from 182,643 person-years of follow-up observation and 397 cases from 178,846 person-years of follow-up observation, respectively. Compared with H2RA users, PPI users did not experience significantly different gastric cancer incidence (adjusted hazard ratio, 1.01; 95% confidence interval, 0.88-1.16; P = 0.89). Sensitivity analyses confirmed that gastric cancer incidence did not differ between PPI and H2RA users. DISCUSSION: In this large study, long-term treatment with PPIs vs H2RAs did not show higher risk of gastric cancer even in a high-risk region.

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.

Increased incidence of metachronous gastric neoplasm after endoscopic resection in patients with synchronous gastric neoplasm.

BACKGROUND: Recurrence risk is a major concern after endoscopic resection (ER) of gastric neoplasms. This study was to compare metachronous risk in patients with and without synchronous neoplasms after complete ER. METHODS: After ER for gastric neoplasms, patients were divided into those with and without synchronous neoplasm. The metachronous risk of gastric neoplasms was compared between the two groups. RESULTS: After ER of 678 cancers and 891 adenomas, synchronous neoplasm was found in 11.8% of cancers and 11.4% of adenomas. In the multiple (n = 182) and the single group (n = 1387), metachronous neoplasms occurred in 18.1 and 8.6%, respectively (HR 2.40; 95% CI, 1.62-3.34). When the pathology of the recurred lesion was limited to cancer, metachronous risk was also significantly higher in the multiple than in the single group (HR, 2.2; 95% CI, 1.17-3.85). In the recurred pathology of the multiple group, cancer development was frequently observed in patients with cancer compared to those with only adenomas in the synchronous lesion (67.0% vs. 13.0%, respectively; P = 0.023). CONCLUSIONS: This study demonstrated that metachronous risk was significantly higher in patients with synchronous gastric neoplasms after ER. Therefore, meticulous examination is important in patients with synchronous neoplasm.

Changes in the biological characteristics of glioma cancer stem cells after serial in vivo subtransplantation.

PURPOSE: Currently, the interaction between the niche and glioma cancer stem cells (gCSCs) is gaining attention. However, there are few studies concerned with the effects of repeated exposure to a new microenvironment on gCSCs characteristics. In this study, serial in vivo subtransplantation was performed to create a new microenvironment. We evaluated and compared the biological characteristics of gCSCs after serial in vivo subtransplantation. METHODS: We cultured gCSCs from human glioma specimens according to cultured gliomasphere methods. The isolated gCSCs were termed zero-generation gCSCs (G0-gCSCs). By subsequent serial subtransplantation, we obtained first-generation gCSCs (G1-gCSCs) and second-generation gCSCs (G2-gCSCs). We evaluated and compared the biological characteristics of G0-gCSCs, G1-gCSCs, and G2-gCSCs. The in vitro characteristics included the morphology, surface marker profiles, and neural differentiation capacity and the in vivo characteristics was the survival of mice xenografts. Additionally, brain sections were analyzed using PCNA, TUNEL, and CD31 staining. RESULTS: We observed no significant differences in the in vitro characteristics of G0-gCSCs, G1-gCSCs, and G2-gCSCs. However, the survival time of mice glioma xenografts was significantly decreased upon serial subtransplantation. In addition, immunohistochemical analyses showed that the number of TUNEL(+) cells was significantly decreased while the number of CD31(+) cells was significantly increased with serial in vivo subtransplantation. CONCLUSIONS: There were significant in vivo biological changes in gCSCs upon serial in vivo subtransplantation, which were shorter xenograft survival, increased angiogenesis, and decreased apoptosis. This study suggests that the repeated exposure to new microenvironments may affect the biological changes in gCSCs in vivo.