Precursor Of Gastric Cancer Research Articles

Highlights of This Issue

Mapping breast cancer survival can help cancer-control programs prioritize efforts with limited resources. Wiese and colleagues used Bayesian spatial models to assess whether geographic variation in breast cancer survival among patients in New Jersey persists after adjusting for key individual and neighborhood measures of poverty and economic inequality. The results support a growing understanding of the independent association between neighborhood socioeconomic measures and breast cancer survival. More effective health interventions could be developed if geographic variations were examined more routinely in the context of neighborhood socioeconomic inequalities in addition to individual characteristics.The impact of processed meat intake on the risk of bladder cancer is not clear. In this study, Xu evaluated the association of processed meat intake with bladder cancer using data from the Prostate, Lung, Colorectal, and Ovarian (PLCO) cohort. As a result, intake of processed red meat was significantly associated with the incidence of bladder cancer after multivariate adjustment. By contrast, there was only a suggestive but not significant association between total processed meat intake and bladder cancer risk. The study suggests that bladder cancer risk is increased with cumulative intake of processed red meat.Infection with Helicobacter pylori can lead to chronic atrophic gastritis, a gastric cancer precursor. Autoimmune gastritis is an alternative form of gastritis that may be marked by autoantibodies against parietal cells (APCA). Wang and colleagues measured seropositivity to APCA in a nested case–control study of upper gastrointestinal cancers in a rural Chinese cohort. The authors found that APCA positivity was associated with lower risk of gastric cancer that was strongest in the gastric cardia. APCA negativity when assessed along with a serologic marker for atrophic gastritis revealed complex and strong associations with gastric cancer that may be useful in risk stratification.Multiple myeloma (MM) is a common hematologic malignancy preceded by monoclonal gammopathy of undetermined significance (MGUS). Chang and colleagues aimed to identify a new clinical predictor to guide MGUS management. Multivariable analyses were performed using data from the U.S. Veterans Health Administration. The rate of rise in serum monoclonal protein concentration of >0.1 g/dL in the year following MGUS diagnosis was positively associated with progression of MGUS to MM. These findings enhance the current risk stratification. The identified clinical predictor is a dynamic measure for disease progression with prognostic value. It has the potential to inform MGUS management and MM prevention.

HELICOBACTER PYLORI INFECTION AND GASTRIC CANCER PRECURSOR LESIONS: PREVALENCE AND ASSOCIATED FACTORS IN A REFERENCE LABORATORY IN SOUTHEASTERN BRAZIL

Helicobacter pylori infection is the most important risk factor for gastric atrophy and intestinal metaplasia, both considered gastric cancer precursor lesions. Therefore, the investigation of the occurrence of H. pylori infection, precursor lesions and associated factors guides the adoption of specific strategies for the control this type of cancer. To evaluate the prevalence of H. pylori infection in patients undergoing upper digestive endoscopy, as well as the prevalence of intestinal metaplasia, atrophy and chronic inflammation and their association with H. pylori infection. A retrospective study was performed based on reports of gastric endoscopic biopsies performed in a private laboratory affiliated to the Brazilian Public Health System (SUS). Patients were evaluated for age, gender and type of health service. The samples were evaluated for the presence of H. pylori, and also of chronic inflammation, intestinal metaplasia and glandular atrophy. Of a total of 4,604 patients (mean age 51±16.6), 63.9% were female and 63.1% coming from private health care service. The prevalence of H. pylori infection was 31.7% (n=1,459), and the percentage of infection was significantly higher in patients from public health service (42.0%) in relation to patients from private health service (25.6%). Among H. pylori (+) patients, a higher percentage of intestinal metaplasia (17.7% vs 13.3%) and glandular atrophy (17.6% vs 6.9%) were observed when compared to those H. pylori (-) (P<0.01). From the patients H. pylori (+) with at least one type of precursor lesion (n=418), 161 (38.5%) had metaplasia and chronic inflammation, 160 (38.3%) had atrophy and chronic inflammation and finally 97 (23.2%) presented metaplasia, atrophy and chronic inflammation simultaneously. The present study reinforces the association of H. pylori infection with gastric cancer precursor lesions in a Brazilian population, emphasizing the importance of infection prevention measures, as well as the treatment of infected patients, especially in regions with lower socioeconomic levels that show a higher prevalence of infection by H. pylori.

Decrease in MiR-148a Expression During Initiation of Chief Cell Transdifferentiation.

Gastric chief cells differentiate from mucous neck cells and develop their mature state at the base of oxyntic glands with expression of secretory zymogen granules. After parietal cell loss, chief cells transdifferentiate into mucous cell metaplasia, designated spasmolytic polypeptide-expressing metaplasia (SPEM), which is considered a candidate precursor of gastric cancer. We examined the range of microRNA (miRNA) expression in chief cells and identified miRNAs involved in chief cell transdifferentiation into SPEM. Among them, miR-148a was strongly and specifically expressed in chief cells and significantly decreased during the process of chief cell transdifferentiation. Interestingly, suppression of miR-148a in a conditionally immortalized chief cell line induced up-regulation of CD44 variant 9 (CD44v9), one of the transcripts expressed at an early stage of SPEM development, and DNA methyltransferase 1 (Dnmt1), an established target of miR-148a. Immunostaining analyses showed that Dnmt1 was up-regulated in SPEM cells as well as in chief cells before the emergence of SPEM in mouse models of acute oxyntic atrophy using either DMP-777 or L635. In the cascade of events that leads to transdifferentiation, miR-148a was down-regulated after acute oxyntic atrophy either in xCT knockout mice or after sulfasalazine inhibition of xCT. These findings suggest that the alteration of miR-148a expression is an early event in the process of chief cell transdifferentiation into SPEM.

Endogenous glucocorticoids prevent gastric metaplasia by suppressing spontaneous inflammation.

In the stomach, chronic inflammation causes metaplasia and creates a favorable environment for the evolution of gastric cancer. Glucocorticoids are steroid hormones that repress proinflammatory stimuli, but their role in the stomach is unknown. In this study, we show that endogenous glucocorticoids are required to maintain gastric homeostasis. Removal of circulating glucocorticoids in mice by adrenalectomy resulted in the rapid onset of spontaneous gastric inflammation, oxyntic atrophy, and spasmolytic polypeptide-expressing metaplasia (SPEM), a putative precursor of gastric cancer. SPEM and oxyntic atrophy occurred independently of lymphocytes. However, depletion of monocytes and macrophages by clodronate treatment or inhibition of gastric monocyte infiltration using the Cx3cr1 knockout mouse model prevented SPEM development. Our results highlight the requirement for endogenous glucocorticoid signaling within the stomach to prevent spontaneous gastric inflammation and metaplasia, and suggest that glucocorticoid deficiency may lead to gastric cancer development.

Can mean platelet volume IndIcate HelIcobacter posItIvIty and severIty of gastrIc InflammatIon? An orIgInal study and revIew of the lIterature.

SUMMARYHelicobacter pylori (H. pylori) is a common problem and a significant cause of chronic gastric inflammation. H. pylori, ongoing gastric inflammation and its severity are the most critical component of precursors of gastric cancer. Hypothetically, every chronic tissue injury activates platelets, and the mean platelet volume (MPV) reflects this action well. The potential relationship between H. pylori and platelet count has been shown before. However, there are few and conflicting papers about the relationship between MPV and H. pylori related chronic gastric inflammation and its severity. The study aimed to assess any potential relationship between MPV and presence of H. pylori, as well as the severity of chronic gastric inflammation. A total of 6890 endoscopic reports were initially evaluated, and a total of 218 dyspeptic patients having undergone upper endoscopy were included. Of these, 118 (54.2%) were H. pylori positive and 100 (45.8%) were H. pylori negative. At least four gastric biopsies were obtained and evaluated according to Sydney classification. Age, gender, hemoglobin, mean corpuscular volume, ferritin, serum iron and C-reactive protein, as well as endoscopic findings were also recorded. A p<0.05 was accepted as significant. The MPV and platelet count did not differ between H. pylori positive and H. pylori negative groups of patients (p>0.05). There were no differences and correlation between MPV and gastric inflammation severity according to Sydney classification (p>0.05). When stratifying MPV as <9.15 fL and >9.15 fL, there was no difference between H. pylori positive and H. pylori negative groups either (p>0.05). In this study, we found no relationship between MPV and presence of H. pylori or severity of gastric inflammation. Although there are still conflicting publications on this issue, in our opinion and according to the results of this study, MPV is not a suitable marker for evaluation of gastric inflammation severity, being H. pylori either positive or negative.

Nonlinear optical microscopy for label-freely detecting gastric intestinal metaplasia

Intestinal metaplasia has been widely considered as a precursor of gastric cancer. As a result, early detection and accurate diagnosis will have important clinical significance. Therefore, nonlinear optical microscopy using two-photon excited fluorescence combined with second harmonic generation was used for investigating gastric mucosal intestinal metaplasia in this work. The imaging results showed that this microscope has the ability to directly identify this lesion from normal tissues in the absence of labels, and to further differentiate the subtyping of intestinal metaplasia. Furthermore, nuclear areas from normal gastric mucosa and intestinal metaplasia subtypes were measured, respectively, to show the cell changes while gastric mucosa developed from normal to intestinal metaplasia. This study may provide an approach for further researching these diseases in the future, and highlights the potential of nonlinear optical microscopy as a diagnostic tool for label-free identification of gastric intestinal metaplasia.

High-risk symptoms do not predict gastric cancer precursors.

Gastric intestinal metaplasia (GIM) is the most common precursor of gastric cancer. Our aim is to determine if presenting symptoms predict gastric cancer precursor lesions in a high-risk population. Consecutive unique patients evaluated by endoscopy for upper gastrointestinal symptoms at the Los Angeles County Hospital between 2010 and 2014 were evaluated. Presenting symptoms were classified as low- or high-risk depending on the procedure indication as coded using the Clinical Outcomes Research Initiative (CORI) system. Endoscopy and histology results were used to classify findings as benign, GIM, high-risk GIM, or malignant. The primary outcome was the proportion of patients with premalignant or malignant gastric findings who had high-risk clinical indications for endoscopy relative to those with benign results. A total of 3699 patients underwent endoscopy to evaluate upper gastrointestinal symptoms. There were 373 (10.1%) patients with GIM of which 278 had high-risk GIM. One hundred and sixty (4.3%) patients were diagnosed with gastric cancer. High-risk indications for upper endoscopy predicted gastric cancer (OR 1.8 [95% CI 1.3-2.6]) but not GIM (OR 1.0 [0.8-1.3]) or high-risk GIM (OR 0.9 [0.7-1.2]). Hispanic or Asian patients and patients >50years old were more likely to have GIM, high-risk GIM, and cancer. Performance of upper endoscopy for high-risk indications is inadequate to detect GIM and marginal for malignancy. At risk patients should undergo upper endoscopy for both low- and high-risk symptoms. Screening certain populations deserve additional study and may, in fact, be cost-effective.

Genetic variation analysis in a follow-up study of gastric cancer precursor lesions confirms the association of MUC2 variants with the evolution of the lesions and identifies a significant association with NFKB1 and CD14.

Gastric carcinogenesis proceeds through a series of gastric cancer precursor lesions (GCPLs) leading to gastric cancer (GC) development. Although Helicobacter pylori infection initiates this process, genetic factors also play a role. We previously reported that genetic variability in MUC2 is associated with the evolution of GCPLs. In order to replicate previous results in an independent sample series and to explore whether genetic variability in other candidate genes plays a role in the evolution of GCPL, genomic DNA from 559 patients with GCPLs, recruited from 9 Spanish hospitals and followed for a mean of 12 years, was genotyped for 141 SNPs in 29 genes. After follow-up, 45.5% of the lesions remained stable, 37% regressed and 17.5% progressed to a more severe lesion. Genetic association with the evolution of the lesions (progression or regression) was analyzed by multinomial and binomial logistic regression. After correction for multiple comparisons, the results obtained confirmed the inverse association between MUC2 variants and the regression of the lesions. A significant association was also observed between NFKB1 and CD14 variants and the evolution of the lesions; interestingly, this association was with both progression and regression in the same direction, which could reflect the dual role of inflammation in cancer. Stratified analyses according to H. pylori virulence factors indicated some significant and differential effects but none of them passed the FDR test. These results confirm that genetic variability in MUC2, NFKB1 and CD14 may have a role in the evolution of the GCPLs along time and in gastric carcinogenesis.

Circulating microRNA-196a is an early gastric cancer biomarker.

MicroRNA-196a (miRNA-196a) is associated with the development of gastric cancer and metastasis. Intestinal metaplasia and low- or high-grade dysplasia are considered to be precursors of intestinal type gastric cancer. Accordingly, we investigated the expression of plasma miRNA-196a as an early detection biomarker in precancerous gastric lesions and early cancer (pT1a/b), which is otherwise treated with endoscopic submucosal dissection. Our data showed that levels of circulating (plasma) miRNA-196a were higher in patients with precancerous lesions/early gastric adenocarcinoma than in healthy controls. The area under the receiver operating characteristic curve (AUC) for healthy controls vs. intestinal metaplasia was 0.9736; healthy controls vs. low-grade/high-grade dysplasia 0.9495; and healthy controls vs. early gastric cancer 0.9318. These results indicate that circulating miRNA-196a is a novel biomarker for detection of early gastric cancer and its precursor.

Eradication Does Not Prevent Metachronous Gastric Cancer

Helicobacter pylori infection is a known risk factor for gastric cancer (GC). Eradication of the infection may reverse some GC precursor states, such

Metaplasia in the Stomach-Precursor of Gastric Cancer?

Despite a significant decrease in the incidence of gastric cancer in Western countries over the past century, gastric cancer is still one of the leading causes of cancer-related deaths worldwide. Most human gastric cancers develop after long-term Helicobacter pylori infection via the Correa pathway: the progression is from gastritis, atrophy, intestinal metaplasia, dysplasia, to cancer. However, it remains unclear whether metaplasia is a direct precursor of gastric cancer or merely a marker of high cancer risk. Here, we review human studies on the relationship between metaplasia and cancer in the stomach, data from mouse models of metaplasia regarding the mechanism of metaplasia development, and the cellular responses induced by H. pylori infection.

Clinical implications of pre-existing adenoma in endoscopically resected early gastric cancers.

BackgroundAlthough gastric adenoma is widely accepted as a precursor of gastric cancer, pre-existing adenoma is not always detected in gastric cancer patients.ObjectiveTo investigate the clinical characteristics of early gastric cancer (EGC) arising from adenoma, compared with those of EGC without pre-existing adenoma.MethodsPatients who underwent endoscopic resection for EGC at a single tertiary hospital were divided into two groups based on the presence (ex-adenoma group) or absence (de novo group) of pre-existing adenoma on pathologic specimens. Clinicopathologic characteristics, endoscopic features and long-term outcomes were analyzed.ResultsOf 1,509 patients, 236 (15.6%) were included in the ex-adenoma group. Mean age (P = 0.003) and Helicobacter pylori infection rate (P = 0.040) were significantly higher in the ex-adenoma than in the de novo group. Mean endoscopic size was significantly larger, elevated lesions were more prevalent (both P < 0.001), and carcinomas were more differentiated in the ex-adenoma group than in the de novo group (P = 0.037). The degree of atrophy (P = 0.025) or intestinal metaplasia (P < 0.001) was more advanced in the ex-adenoma group. Synchronous gastric neoplasia was significantly more prevalent in the ex-adenoma group (P < 0.001), whereas metachronous cancer recurrence rate was not significantly different between the two groups.ConclusionsEGCs with pre-existing adenoma show a greater association with H. pylori–related chronic inflammation than those without, which could explain the differences in the characteristics between groups. Potential differences in carcinogenic mechanisms between the groups were explored.

Plasma ghrelin level and plasma ghrelin/obestatin ratio are related to intestinal metaplasia in elderly patients with functional dyspepsia.

BackgroundWhether plasma ghrelin/obestatin levels are associated with Helicobacter pylori (H. pylori) infection, subtypes of functional dyspepsia (FD), and gastric mucosal histology has not yet been established in elderly patients.ObjectiveThe aim of this study was to determine whether plasma ghrelin and obestatin levels are related to gastric mucosal histology, H. pylori infection, and FD subtypes in elderly patients with FD.MethodsNinety-two patients diagnosed with FD and older than 60 years (median age 69.4; range 60–88) were included. Clinical symptoms investigated included postprandial fullness, epigastric pain, epigastric soreness, nausea, and vomiting. According to the Rome III criteria, patients diagnosed with FD were divided into two subtypes: epigastric pain syndrome (EPS) and postprandial distress syndrome (PDS). Plasma ghrelin and obestatin levels were measured using enzyme immunoassay, and histological examination of gastric mucosa was performed. H. pylori infection was determined by histopathological examination of gastric mucosal biopsy and/or Campylobacter-like organism test.ResultsIn our study, plasma ghrelin levels and plasma ghrelin/obestatin (G/O) ratio were significantly lower in subjects with intestinal metaplasia compared with those without intestinal metaplasia (ghrelin, p = 0.010; G/O ratio, p = 0.012). On the other hand, there were no significant differences in plasma ghrelin and obestatin levels between H. pylori–positive and H. pylori–negative groups. (ghrelin, p = 0.130; obestatin, p = 0.888). Similarly, no significant differences were detected between the EPS and PDS groups (ghrelin, p = 0.238; obestatin, p = 0.710).ConclusionsPatients with intestinal metaplasia, a known precursor of gastric cancer, had significantly less plasma ghrelin levels and G/O ratio than those without intestinal metaplasia.

Narrow-band imaging versus white light versus mapping biopsy for gastric intestinal metaplasia: a prospective blinded trial

Gastric intestinal metaplasia (GIM) is a gastric cancer precursor. Narrow-band imaging (NBI) may improve detection of GIM. We compared detection of GIM with high-definition white-light (HD-WL) endoscopy, NBI, and mapping biopsies in a population with increased gastric cancer risk. Patients undergoing upper endoscopy had HD-WL examination by 1 endoscopist, followed by an NBI examination by a second endoscopist blinded to HD-WL findings. The location of abnormalities detected by HD-WL and NBI were recorded by a research coordinator, and targeted biopsies of abnormal areas were performed after NBI. Subsequently, 5 mapping biopsies were performed per patient. Biopsy specimens were read by a pathologist blinded to mode of acquisition. The primary outcome was the proportion of patients with GIM. We enrolled 112 patients: 107 (96%) were Hispanic or Asian, and 34 (30%) had GIM. Higher proportions of patients with GIM were detected by NBI (22/34 [65%]) and mapping (26/34 [76%]) versus HD-WL (10/34 [29%]) (P< .005 for both comparisons). GIM was detected by NBI in only 6 patients and only by mapping biopsy in 10 patients; no patient had GIM detected solely by HD-WL. Higher proportions of sites with GIM also were detected with NBI (30/57 [53%]) and mapping biopsies (38/57 [67%]) than HD-WL (16/57 [28%]) (P< .005 for both comparisons). The median number of biopsies per patient with mapping biopsies (5) was significantly higher than with NBI (2) or HD-WL (1). HD-WL endoscopy is insufficient for detection of GIM in patients at increased risk for gastric cancer. NBI-targeted biopsies plus mapping biopsies should be used. (Clinical trial registration number: NCT02197351.).

Human papillomavirus as a potential risk factor for gastric cancer: a meta-analysis of 1,917 cases.

BackgroundHuman papillomaviruses (HPVs) are causally associated with the tumorigenesis of several classes of cancers. However, the prevalence of HPV in gastric cancer (GC) has not yet been systematically reviewed. Hence, a meta-analysis was conducted to estimate the HPV prevalence in patients with GC, and its potential etiologic significance was assessed.MethodsThe pooled HPV prevalence and 95% confidence intervals (CIs) were estimated among all GC patients. Heterogeneity was described by using the I2 statistic. Sources of heterogeneity were explored by meta-regression and stratified analyses. The meta-influence was applied to evaluate the influence of a single study on the pooled estimates. Odds ratios (ORs) and 95% CIs were computed for case–control studies. For research providing clinicopathological parameters of age, sex, pathological, differentiated, and clinical stages, and HPV subtypes, the corresponding pooled ORs and 95% CIs were also calculated.ResultsThirty studies were included in the current meta-analysis, involving 1,917 patients with GC and 576 controls. The pooled HPV prevalence was 28.0% (95% CI: 23.2%, 32.7%) among all the patients with GC, and the I2 was 96.9% (P<0.001). A pooled OR of 7.388 (95% CI: 3.876, 14.082) was achieved based on 15 case–control studies (I2=56.7%, P=0.004). Moreover, the HPV prevalence was significantly higher in patients from China than in those from non-Chinese regions (31% vs 9%, I2=95.0%, P<0.001). The pooled prevalence of HPV16 was 21% in GC tissues, and the pooled prevalence of HPV18 was 7% with an OR of 3.314 (95% CI =1.617, 6.792). HPV16 was 3 times more frequently detected than HPV18.ConclusionHPV could play a potential role in the pathogenesis of GC. A causal relationship can be confirmed only by detecting HPV in the cells of GC precursor lesions (gastric dysplasia or adenoma). In addition, this study might be beneficial for expounding the potential etiologic significance of molecular mechanism of gastric tumorigenesis and providing opinions regarding precautionary measures.

SCHLAFEN 5 expression correlates with intestinal metaplasia that progresses to gastric cancer.

Intestinal metaplasia (IM) is a gastric cancer precursor lesion (GCPL) and an extremely high risk factor for progression to gastric cancer (GC). Clinical guidelines recommend that patients with extensive IM undergo a gastroscopy every 3years. However, protein biomarkers that indicate a transition from IM to GC are lacking. Our group recently identified an interferon-alpha (IFNα)-responsive gene, Schlafen 4 (Slfn4), in immune cells that correlates with metaplastic changes in Helicobacter-infected mice. We therefore tested the hypothesis that a human homolog of Slfn4, namely, Schlafen 5 (SLFN5), correlates with progression of GCPL to GC. Jurkat T-lymphoid and HL-60 myeloid cell lines were treated with IFNα, and SLFN5 mRNA was quantified by quantitative PCR. SLFN5 protein expression in the inflamed gastric mucosa was co-localized to specific immune cell types by immunohistochemistry using CD20, CD2, and MAC2 antibodies. SLFN5 expression was also determined by immunohistochemistry in formalin-fixed paraffin-embedded samples from individuals with non-atrophic gastritis, atrophic gastritis, complete IM, incomplete IM, and GC, respectively. The IFNα treatment of Jurkat and HL-60 cells induced SLFN5 mRNA. SLFN5 protein was expressed mainly by T lymphocytes in inflamed gastric mucosa. The highest level of SLFN5 expression was observed in patients with IM that progressed to GC. Receiver operating characteristic curves demonstrated that correlating SLFN5 expression with the histologic diagnosis of IM significantly increased the probability of identifying patients who may progress to GC. In this study population, elevated SLFN5 protein expression in patients with IM correlated with progression to GC.

Diagnosis and management of gastric dysplasia.

Gastric dysplasia is a neoplastic lesion and a precursor of gastric cancer. The Padova, Vienna, and World Health Organization classifications were developed to overcome the discrepancies between Western and Japanese pathologic diagnoses and to provide a universally accepted classification of gastric epithelial neoplasia. At present, the natural history of gastric dysplasia is unclear. Much evidence suggests that patients with high-grade dysplasia are at high risk of progression to carcinoma or synchronous carcinoma. Therefore, endoscopic resection is required. Although patients with low-grade dysplasia have been reported to be at low risk of progression to carcinoma, due to the marked histologic discrepancies between forceps biopsy and endoscopic specimens, endoscopic resection for this lesion is recommended, particularly in the presence of other risk factors (large size; depressed gross type; surface erythema, unevenness, ulcer, or erosion; and tubulovillous or villous histology). Helicobacter pylori eradication in patients with dysplasia after endoscopic resection appear to reduce the incidence of metachronous lesions.

Gastric Metaplasia Induced by Helicobacter pylori Is Associated with Enhanced SOX9 Expression via Interleukin-1 Signaling.

Histopathological changes of the gastric mucosa after Helicobacter pylori infection, such as atrophy, metaplasia, and dysplasia, are considered to be precursors of gastric cancer, yet the mechanisms of histological progression are unknown. The aim of this study was to analyze the histopathological features of the gastric mucosa in mice infected with H. pylori strain PMSS1 in relation to gastric stem cell marker expression. C57BL/6J mice infected with PMSS1 were examined for histopathological changes, levels of proinflammatory cytokines, and expression of stem cell markers. Histopathological gastritis scores, such as atrophy and metaplasia, and levels of proinflammatory cytokines, such as tumor necrosis factor alpha (TNF-α) and interleukin-1β (IL-1β), were increased after PMSS1 infection. Expression levels of the cell proliferation and stem cell markers CD44 and SOX9 were also significantly increased in PMSS1-infected mice. Importantly, almost all metaplastic cells induced by PMSS1 infection expressed SOX9. When IL-1 receptor (IL-1R) knockout mice were infected with PMSS1, metaplastic changes and expression levels of stem cell markers were significantly decreased compared with those in wild-type (WT) mice. In conclusion, H. pylori infection induced the expression of cytokines and stem cell markers and histopathological metaplasia in the mouse gastric mucosa. SOX9 expression, in particular, was strongly associated with metaplastic changes, and these changes were dependent on IL-1 signaling. The results suggested the importance of SOX9 in gastric carcinogenesis.

Sa1927 Significant Genetic Variability Associated With the Evolution of Gastric Cancer Precursor Lesions in a Spanish Population

Objective Preoperative chemoradiotherapy has recently become common practice in treatment of esophageal cancer with a gain in 5-year survival of 10-15%. However, a significant proportion of patients do not respond well and experiencing unnecessary severe side-effects. Accurate risk-stratification of patients using informative biomarkers before therapy may help to avoid unnecessary morbidity due to ineffective treatment. The aim of this study was to investigate the correlation between the expression of SOX2 and P53 in pre-treatment tumor biopsies and grade of pathological tumor response in resected specimen of patients with esophageal adenocarcinoma (EAC) treated with neoadjuvant chemoradiotherapy (nCRT). Methods All EAC patients who received nCRT according to the CROSS regimen followed by esophagectomy, between January 2003 and July 2011 at the Erasmus University Medical Center, were included. SOX2 and P53 protein expression was visualized by immunohistochemistry on all pre-treatment tumor biopsies and scored independently by two investigators who were blinded for clinical outcome. Aberrant expression was defined as negative expression of SOX2 and overexpression or complete loss of P53 expression. The overall Tumor Regression Grade (TRG) was evaluated using the modified Mandard scoring system. Patients with TRG 1 or TRG 2 were classified as major responders (ie, 10% of tumor cells remaining). Results In total 77 patients were included. Forty (53%) patients had a major pathological response (TRG 1-2) and 37 (47%) a minor response (TRG 3-4). In pre-treatment biopsies aberrant SOX2 and P53 expression was seen in 40% (31/77) and 83% (64/77), respectively. A major response was significantly associated with an aberrant SOX2 expression (OR 3.9, 95% CI: 1.5 10.2, p=0.005) and aberrant p53 expression (OR 4.5, 95% CI: 1.15 18.2, p=0.031). Aberrant expression of both biomarkers increased the probability of a major response in the individual patient (OR of 5.6; 95% CI: 2.1 14.9, p= 0.001), with a sensitivity of 68%, specificity of 73% and a positive predictive value of 73%. Conclusion SOX2 and P53 expression in the pre-treatment biopsies predict response to nCRT in patients with EAC. These biomarkers might help to identify patients who are likely to benefit most from this multimodality treatment.

Risk Factors of Chronic Atrophic Gastritis

Background: Chronic atrophic gastritis is a well-established precursor of gastric cancer. The development of atrophic chronic gastritis is multifactorial, involving the environment as well as host responses to the Helicobacter pylori (H. pylori) infection. The aim of this study is to determine prevalence and risk factors of chronic atrophic gastritis.Method: The study was a cross sectional study on gastritis patients admitted to endoscopy units at Adam Malik General Hospital and Permata Bunda Hospital, Medan, from May-October 2014. A simple random sampling was performed to obtain 50 patients. Data concerning sociodemographic factors and H. pylori status were collected. H. pylori were considered positive from the positive results of the campylobacter like organism (CLO) test. Univariate and bivariate analyses were performed using the SPSS 22 with 95% confidence interval. Bivariat analysis was performed using a Chi-square test. Results: Prevalence of chronic atrophic gastritis was 40%. There were associations between age and chronic atrophic gastritis (95% CI = 1.05-2.80; p = 0.021; OR = 1.73), body mass index and chronic atrophic gastritis (95% CI = 1.1-3.1; p = 0.011; OR = 1.85), and H.pylori infection and chronic atrophic gastritis (95% CI = 1.23-4.88; OR = 2.45; p = 0.001). There were no associations between gender, ethnicity, or rural-urban classification and chronic atrophic gastritis (p 0.05).Conclusion: Elderly status, low BMI, and H. pylori infection are risk factors for the development of chronic atrophic gastritis. Keywords: chronic atrophic gastritis, Helicobacter pylori, gastric atrophy, body mass index