Background/Aims: Altered DNA methylation is a key mechanism of epigenetic modification in gastric cancer (GC). This study aimed to evaluate the changes in epigenetic and genetic expression of multiple Rho GTPases in Helicobacter pylori-related gastric carcinogenesis by comparing H. pylori-positive GCs and negative controls. Methods: The messenger RNA expression and methylation of Rho GTPases (RhoA, Rac1, DOCK180, ELMO1, and CDC42) were evaluated in H. pylori-negative (control) human gastric tissues and H. pylori-positive GCs by using real-time reverse transcription-polymerase chain reaction and the quantitative MethyLight assay, respectively. Changes in expression and methylation levels of the genes were also compared between H. pylori-eradicated and -persistent GCs at 1-year follow-up. Results: In GCs, the methylation and expression levels of DOCK180 and ELMO1 were higher than in controls, while RhoA and Rac1 had lower levels than controls. CDC42 had the same expression pattern as DOCK180 and ELMO1 without DNA methylation. Although methylation levels of DOCK180 and ELMO1 had no difference betweenH. pylori-eradicated and -persistent GCs at the index endoscopic resection, those of H. pylori-persistent GCs increased and H. pylorieradicated GCs decreased for 1 year. The expression levels of DOCK180, ELMO1, and CDC42 in H. pylori-persistent GCs were higher than those in H. pylori-eradicated GCs over 1 year, unlike those of RhoA and Rac1. The methylation levels at index and the degrees of change over time of RhoA and Rac1 had no difference between H. pylori-persistent and -eradicated GCs. Conclusions Epigenetic alterations of DOCK180 and ELMO1 are involved in H. pylori-related gastric carcinogenesis. This epigenetic field could be improved by H. pylori eradication.

Background/Aims: Patients treated with endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) are at risk of developing metachronous gastric cancer (MGC).The aim of this study was to evaluate the clinical outcomes of MGC after ESD for EGC between the re-ESD and surgery groups. Methods: In total, data from 1,510 patients who underwent ESD for EGC from January 2005 to May 2014were retrospectively reviewed, and data from 112 patients with MGC were analyzed according to the type of treatment, namely, re-ESD and surgery. The clinicopathological factors affecting the subsequent treatment and outcomes of MGC were evaluated. Results: The median duration to the development of MGC was 47 months. In multivariate analysis, lower body mass index (BMI) (p=0.037) and multiplicity (p=0.014) of index cases were significantly associated with subsequent surgery for MGC. In cases of MGC, a diffuse or mixed-type Lauren classification (p=0.009), the depth of tumor mucosal invasion (p=0.001), and an upper stomach location (p=0.049) were associated with surgery. Overall survival was significantly shorter in the surgery group than in the re-ESD group after treatment for MGC (log-rank test, p=0.01). Conclusions Lower BMI and multiplicity of index cancers were significantly associated with the surgical resection of MGC. Close follow-up is needed to minimize additional treatment for cases at high risk of advanced MGC after ESD for EGC.

BACKGROUND/AIMS: Current guidelines recommend withholding antiplatelets for 5–7 days before high-risk endoscopic procedures. We investigated whether this reduces post-endoscopic submucosal dissection (ESD) bleeding. METHODS: Gastric ESD cases with antiplatelets were retorospectively reviewed. Withholding antiplatelets for 5–7 days before ESD was defined as cessation and 0–4 days as continuation. The rate and risk of post-ESD bleeding according to the types and cessation of antiplatelets were assessed. RESULTS: Among the 215 patients (117 adenoma and 98 early gastric cancer), 161 patients were on single (94 aspirin, 56 thienopyridine, and 11 other agents), 51 on dual, and 3 on triple antiplatelets. Post-ESD bleeding rates were 12.8% in aspirin users, 3.6% in thienopyridine, 27.5% in dual, 33.3% in triple therapy, and 9.7% in the cessation and 15.0% in the continuation group. Multiple antiplatelets (odds ratio [OR], 2.41; 95% confidence interval [CI], 1.01 to 5.76) and specimen size ≥ 5.5 cm (OR, 2.84; 95% CI, 1.04 to 7.73) were the risk of bleeding, while continuation of thienopyridine (OR, 0.23; 95% CI, 0.05 to 1.09) and antiplatelets (OR, 1.83; 95% CI, 0.68 to 4.94) did not increase the risk of bleeding. CONCLUSIONS: Continuing thienopyridine and aspirin did not increase the risk of post-ESD. Multiple antiplatelet therapy and a large specimen size were independent risk factors of post-ESD bleeding.
Adenoma ; Aspirin* ; Hemorrhage ; Humans ; Risk Factors

Purpose: The impact of the interval between previous endoscopy and diagnosis on the treatment modality or mortality of undifferentiated (UD)-type gastric cancer is unclear. This study aimed to investigate the effect of endoscopic screening interval on the stage, cancerrelated mortality, and treatment methods of UD-type gastric cancer. Materials and Methods: We reviewed the medical records of newly diagnosed patients with UD gastric cancer in 2013, in whom the interval between previous endoscopy and diagnosis could be determined. The patients were classified into different groups according to the period from the previous endoscopy to diagnosis (<12 months, 12–23 months, 24–35 months, ≥36 months, and no history of endoscopy), and the outcomes were compared between the groups. In addition, patients who underwent endoscopic and surgical treatment were reclassified based on the final treatment results. Results: The number of enrolled patients was 440, with males representing 64.1% of the study population; 11.8% of the participants reported that they had undergone endoscopy for the first time in their cancer diagnosis. The percentage of stage I cancer at diagnosis significantly decreased as the interval from the previous endoscopy to diagnosis increased (65.4%, 63.2%, 64.2%, 45.9%, and 35.2% for intervals of <12 months, 12–23 months, 24–35 months, ≥36 months, and no previous endoscopy, respectively, P<0.01). Cancer-related mortality was significantly lower for a 3-year interval of endoscopy (P<0.001). Conclusions A 3-year interval of endoscopic screening reduces gastric-cancer-related mortality, particularly in cases of UD histology.