Objective: Epstein-Barr virus (EBV)-associated gastric cancer has been proposed to be a distinct gastric cancer molecular subtype. The prognostic significance of EBV infection in gastric cancer remains unclear and needs further investigation. Our study aimed to analyze EBV-positive and EBV-negative gastric cancer patients regarding their personal and tumor-related characteristics, and compare their overall survival. Methods: Gastric cancer patients consecutively treated at the Riga East University Hospital during 2009–2016 were identified retrospectively. Tumor EBV status was determined by in-situ hybridization for EBV-encoded RNA (EBER). Information about clinicopathological characteristics was obtained from patient questionnaires, hospital records. Overall survival was ascertained through 30 July 2017. Cox proportional hazard regression models adjusted for personal and tumor-related covariates compared survival between EBV-positive and EBV-negative patients. Results: There were a total of 302 gastric cancer patients (61% males) with mean and SD age 63.6 ± 11.5 years. EBER positivity was present in 8.6% of tumors. EBV-positive gastric cancer patients had better survival at 80 months [adjusted hazard ratio = 0.37, 95% confidence interval (CI) = 0.19–0.72] compared to EBV-negative patients. Worse survival was observed for patients with stage III (hazard ratio = 2.76, 95% CI = 1.67–4.56) and stage IV (hazard ratio = 10.02, 95% CI = 5.72–17.57) compared to stage I gastric cancer, and overlapping and unspecified subsite (hazard ratio = 1.85; 95% CI = 1.14; 3.00) compared to distal tumors. Conclusion: Tumor EBV positivity is a favorable prognostic factor in gastric cancer.

Objectives: The aim of the study was to determine the proportion of gastric cancer patients with decreased levels of pepsinogen and gastrin-17 in plasma, with the goal of providing indirect evidence of the sensitivity of these biomarkers when applied in a cancer screening setting. Methods: The levels of pepsinogens I and II, gastrin-17, and Helicobacter pylori immunoglobulin antibodies in plasma samples of gastric cancer patients were evaluated using the GastroPanel test system (Biohit Oyj, Helsinki, Finland). A decreased level of the pepsinogen I/II ratio was defined as less than three, while a decrease in gastrin-17 was defined as less than 1 pmol/L. Univariate analysis using non-parametric tests was used to investigate differences between normal and low concentrations of biomarkers. Results: In total, 481 plasma samples from patients (59.9% male) with a median age of 64 years (ranging from 27 to 88 years) were analyzed. Out of the 400 cases of gastric cancer (83.2% of the total), 182 were categorized as the intestinal type, 141 as the diffuse type, 60 as the mixed type, and 17 as indeterminate according to the Lauren classification system. The H. pylori immunoglobulin test was positive in 74.0% of the patients. Pepsinogen I/II ratio was decreased in 32.4% (36.8% of the intestinal type); gastrin-17 in 12.3% (10.1% of the antral region) of all cases. Conclusion: The majority of gastric cancer patients had normal levels of pepsinogen and gastrin-17, suggesting that these biomarkers have limited application as screening tools in the Caucasian population.

As of today, there is a lack of a perfect non-invasive test for the surveillance of patients for potential relapse following curative treatment. Breath volatile organic compounds (VOCs) have been demonstrated to be an accurate diagnostic tool for gastric cancer (GC) detection; here, we aimed to prove the yield of the markers in surveillance, i.e., following curative surgical management. Patients were sampled in regular intervals before and within 3 years following curative surgery for GC; gas chromatography-mass spectrometry (GC-MS) and nanosensor technologies were used for the VOC assessment. GC-MS measurements revealed a single VOC (14b-Pregnane) that significantly decreased at 12 months, and three VOCs (Isochiapin B, Dotriacontane, Threitol, 2-O-octyl-) that decreased at 18 months following surgery. The nanomaterial-based sensors S9 and S14 revealed changes in the breath VOC content 9 months after surgery. Our study results confirm the cancer origin of the particular VOCs, as well as suggest the value of breath VOC testing for cancer patient surveillance, either during the treatment phase or thereafter, for potential relapse.

Background: A potential association between proton-pump inhibitors (PPI) and gastric cancer remains undefined. Thus, we aimed to evaluate such association within the Stomach cancer Pooling (StoP) Project. Methods: Data from five case–control studies of the StoP Project were included (1,889 cases and 6,517 controls). We assessed the impact of different exposure definitions, specifically any reported use of PPIs and exposure definitions based on the duration of PPI intake. Additionally, we modeled the dose–response relationship between the cumulative duration of PPI intake and gastric cancer. Results: Significant associations between PPI intake and gastric cancer, both overall and in the stratified analyses, were limited to exposure definitions based on short durations of intake. The overall odds ratio (OR) for any reported PPI intake was 1.78 [95% confidence interval (CI): 0.76–4.14]. In the dose–response analysis, the ORs of gastric cancer were found to be higher for short durations of PPI intake (6 months: OR 3.26; 95% CI: 2.40–4.42; one year: OR 2.14; 95% CI: 1.69–2.70; 2 years: OR 1.50; 95% CI: 1.22–1.85; 3 years: OR 1.27; 95% CI: 1.03–1.56), with the association becoming not significant for durations longer than 3 years. Conclusions: Our findings suggest that the observed association between PPIs and gastric cancer might be mainly due to reverse causality. Impact: The results of this study suggest that PPIs are a safe therapeutic choice regarding their effect on the occurrence of gastric cancer. See related commentary by Richman and Leiman, p. 1127

Clinical guidelines recommend particular approaches, including ‘screen-and-treat’ strategy for Helicobacter pylori, to prevent gastric cancer. However, little of this is implemented in clinical practice. The aim of the study was to identify barriers to implementation of international guidelines. A web-based questionnaire distributed globally to specialists in the field. Altogether 886 responses from 75 countries were received. Of the responders, 570 (64%) were men of mean age 47 years. There were 606 gastroenterologists and 65 epidemiologists among the responders. Altogether, 79.8% of the responders disagreed that the burden of gastric cancer is a diminishing problem. ‘Screen-and-treat’ strategy for H. pylori in the responder’s country was considered appropriate by 44.4%, inappropriate by 24.3%, with 31.3% being uncertain. Population-based screening for gastric cancer was considered appropriate in the respective home-country by 62.2%, in other areas – but not the home country – by 27.6%, and inappropriate by 10.2%. As a screening tool, upper endoscopy was acceptable by 35.6%, upper X-ray series by 55.3%, pepsinogens by 26.2% and breath-tests by 23.4%; accuracy, cost-effectiveness and feasibility among the tests varied widely. The attitude towards H. pylori vaccination was that 4.6% of the responders were eager to start vaccination immediately, 55.9% were supporting vaccination but considered that more data are required 12% were negative, and 27.6% did not have an opinion. In general, the attitude of the specialists was in line with guidelines, but was not always translated into clinical practice, particularly in the case of ‘screen-and-treat’ strategy.