• Journal of Gastric Cancer
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• v.10 no.4
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• pp.149-154
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• 2010

Purpose: Replication error is an important mechanism in carcinogenesis. The microsatellite instability (MSI-H) of colorectal cancers is associated with the development of multiple cancers. The influence of MSI-H on the development of multiple gastric cancers in sporadic gastric cancer patients has not been defined. This study was performed to reveal the association between the clinicopathologic features and MSI in sporadic gastric cancers. Materials and Methods: Between July 2004 and March 2009, the clinicopathologic characteristics, including MSI status, were evaluated in 128 consecutive patients with sporadic gastric cancers. None of the patients had hereditary non-polyposis colorectal cancer of familial gastric cancer. The markers that were recommended by the NCI to determine the MSI status for colorectal cancers were used Results: MSI-H cancers were found in 10.9% of the patients (14/128). Synchronous gastric cancers were shown in 4 patients (3.1%). Synchronous cancers were found in 2 of 14 patients with MSI-H gastric cancer (14.3%) and 2 of 114 patients with MSS gastric cancer (1.8%; P=0.059, Fisher's exact test). Among the patients with synchronous cancer 50% (2/4) had MSI-H cancer, but 9.7% of the patients (12/124) without synchronous cancer had MSI-H cancer. MSI-H (RR, 24.7; 95% CI, 1.5~398.9; P=0.024) was related with to synchronous gastric cancer, but age, gender, family history, histologic type, location, gross morphology, size, and stage were not related to synchronous gastric cancer. Conclusions: MSI is associated with the intestinal-type gastric cancer and the presence of multiple gastric cancers in patients with sporadic gastric cancer. Special attention to the presence of synchronous and the development of metachronous multiple cancer in patients with MSI-H gastric cancer is needed.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.23
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• pp.10489-10493
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• 2015

Background: Gastric cancer is the second most common gastrointestinal cancer and is largely attributed to Helicobacter pylori (H. pylori) infection. In addition, studies have also shown association with Epstein-Barr virus (EBV) in 10% of gastric cancers. This study assessed the characteristics of EBV associated gastric cancers (EBVaGC) in Brunei Darussalam. Materials and Methods: This study included gastric cancers diagnosed between 2008 and 2012, registered with the Department of Pathology RIPAS Hospital, Brunei Darussalam. Clinical case notes were systematically reviewed. Histology specimens were all stained for EBV and also assessed for intestinal metaplasia and H. pylori. Results: There were a total of 81 patients (54 male and 27 females) with a mean age of $65.8{\pm}14.8years$ included in the study. Intestinal metaplasia and active H. pylori infection were detected in 40.7% and 30.9% respectively. A majority of the tumors were proximally located (55.6%), most poorly differentiated (well differentiated 16%, moderately differentiated 30.9% and poorly differentiated 53.1%) and the stages at diagnosis were; stage I (44.4%), stage II (23.5%), stage III (8.6%) and stage IV (23.5%). EBV positivity (EBVaGC) was seen in 30.9%. Between EBVaGC and EBV negative gastric cancers, there were no significant differences (age, gender, ethnic group, presence of Intestinal metaplasia, tumor locations, stages of disease and degree of tumor differentiation). Conclusions: This study showed that a third of gastric cancers in Brunei Darussalam were positive for EBV, higher than what have been reported in the literature. However, there were no significant differences between EBVaGC and EBV negative gastric cancers. This suggests that the role of EBV in gastric cancer may be mostly incidental rather than any causal relation. However, further studies are required.

• Journal of Gastric Cancer
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• v.10 no.3
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• pp.91-98
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• 2010

Purpose: Silent mating-type information regulation 2 homologue 1 (SIRT1) is a nicotinamide adenine dinucleotide-dependent deacetylase. SIRT1 plays an important role in the regulation of cell death/survival and stress response in mammals. The aim of this study was to investigate whether the SIRT1 gene is involved in the development or progression of gastric cancers. Materials and Methods: SIRT1 and p53 genes in 86 gastric cancers were examined for genetic alterations by PCR-single strand conformation polymorphism sequencing, as well as SIRT1 protein expression in 170 gastric cancers by immunohistochemistry. Results: In the genetic analysis, we found SIRT1 and p53 mutations in two and 12 cases, respectively. Two missense mutations, c.599 C>T (T200I) and c.1258 G>A (E420K), were detected in the SIRT1 gene coding region. The SIRT1 and p53 mutation were found in mutually exclusive gastric cancers. The immunohistochemistry revealed that SIRT1 overexpression was found in 95 (55.9%) of 170 gastric cancers. Altered SIRT1 expression was not statistically associated with clinicopathological parameters, including tumor differentiation, location, lymph node metastasis, or p53 expression. Two cases with an SIRT1 mutation showed increased SIRT1 expression. Conclusions: These results suggest that genetic alterations and overexpression of the SIRT1 gene may contribute to gastric cancer development.

• BMB Reports
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• v.40 no.2
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• pp.142-150
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• 2007

Epigenetic alterations, represented by aberrant DNA methylation, are deeply involved in human cancers. In gastric cancers, tumor-suppressor genes are inactivated more frequently by promoter methylation than by mutations. We recently showed that H. pylori infection, a potent gastric carcinogenic factor, induces methylation of specific genes in the gastric mucosae. When the methylation levels were analyzed in the gastric mucosae of healthy volunteers, cases with a single gastric cancer, and cases with multiple gastric cancers, who have increasing levels of risks for gastric cancers, there was a significant increasing trend in the methylation levels among the individuals without current H. pylori infection. This finding unequivocally showed the presence of an epigenetic field for cancerization. The degree of the field defect was measured more conveniently using methylation levels of marker genes than using those of tumor-suppressor genes. The presence of an epigenetic field for cancerization has been indicated for liver, colon, Barrett's esophageal, lung, breast, and renal cancers. Since decreased transcription is involved in the specificity of methylated genes, it is likely that specific genes are methylated according to carcinogenic factors. These findings emphasize the usefulness of DNA methylation as a marker for past exposure to carcinogens and future risk of cancer development.

• Clinical Endoscopy
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• v.51 no.6
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• pp.513-526
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• 2018

White light imaging (WLI) may not reveal early upper gastrointestinal cancers. Linked color imaging (LCI) produces bright images in the distant view and is performed for the same screening indications as WLI. LCI and blue laser imaging (BLI) provide excellent visibility of gastric cancers in high color contrast with respect to the surrounding tissue. The characteristic purple and green color of metaplasias on LCI and BLI, respectively, serve to increase the contrast while visualizing gastric cancers regardless of a history of Helicobacter pylori eradication. LCI facilitates color-based recognition of early gastric cancers of all morphological types, including flat lesions or those in an H. pylori-negative normal background mucosa as well as the diagnosis of inflamed mucosae including erosions. LCI reveals changes in mucosal color before the appearance of morphological changes in various gastric lesions. BLI is superior to LCI in the detection of early esophageal cancers and abnormal findings of microstructure and microvasculature in close-up views of upper gastrointestinal cancers. Excellent images can also be obtained with transnasal endoscopy. Using a combination of these modalities allows one to obtain images useful for establishing a diagnosis. It is important to observe esophageal cancers (brown) using BLI and gastric cancers (orange) surrounded by intestinal metaplasia (purple) and duodenal cancers (orange) by LCI.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.5
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• pp.2027-2029
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• 2015

Background: Laparoscope-assisted gastrectomy in treating patients with gastric cancers developed with a background of highly invasive traditional surgery and is being increasingly performed in the Asian Pacific area. This study systemically investigated the technique and clinical results for comparison with traditional radical subtotal gastrectomy for gastric cancers. Methods: Clinical studies evaluating the effectiveness and side effects of laparoscope-assisted gastrectomy in treating patients with gastric cancers were identified using a predefined search strategy. Summary rates of effectiveness and side effects of laparoscope-assisted gastrectomy were calculated. Results: Thirteen clinical studies which including 1,412 patients with gastric cancer treated by laparoscope-assisted gastrectomy were considered eligible for inclusion. Systemic analysis showed that, for all patients, the pooled resection rate was 100%. Major adverse effects were anastomotic stenosis, abdominal abscess, abdominal bleeding, postoperative ileus. Treatment related death occurred in 0. 71% (10/1412). Conclusion: This systemic analysis suggests that laparoscope-assisted gastrectomy in treating patients with gastric cancers is associated with good curative rate and acceptable complications.

• Journal of Gastric Cancer
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• v.19 no.2
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• pp.139-147
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• 2019

The incidence of esophagogastric junction (EGJ) cancer has been significantly increasing in Western countries. Appropriate planning for surgical therapy requires a reliable classification of EGJ cancers with respect to their exact location. Clinically, the most accepted classification of EGJ cancers is "adenocarcinoma of the EGJ" (AEG or "Siewert"), which divides tumor center localization into AEG type I (distal esophagus), AEG type II ("true junction"), and AEG type III (subcardial stomach). Treatment strategies in western countries routinely employ perioperative chemotherapy or neoadjuvant chemoradiation for cases of locally advanced cancers. The standard surgical treatment strategies are esophagectomy for AEG type I and gastrectomy for AEG type III cancers. For "true junctional cancers," i.e., AEG type II, whether the extension of resection in the oral or aboral direction represents the most effective surgical therapy remains debatable. This article reviews the history of surgical EGJ cancer treatment and current surgical strategies from a Western perspective.

• Molecular & Cellular Toxicology
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• v.5 no.4
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• pp.328-334
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• 2009

TBX3 has demonstrated oncogenic activity as a downstream target of the Wnt/$\beta$-catenin signaling pathway. In this study, the aim was to determine whether overexpression of the TBX3 protein is involved in the development and/or progression of gastric cancers. We analyzed the expression pattern of the TBX3 and $\beta$-catenin proteins in a series of 186 sporadic gastric cancers. Altered expression of the TBX3 and $\beta$-catenin proteins was observed in 54 (29.0%) and 48 (25.8%) of the 186 gastric cancers. Statistically, overexpression of the TBX3 and $\beta$-catenin proteins was not associated with the clinical and pathological parameters studied including: histological type, tumor location, tumor size, and the 5-year survival (P>0.05). However, TBX3 overexpression was closely associated with lymph node metastasis and aberrant $\beta$-catenin expression (P<0.05). In addition, overexpression of the TBX3 protein was confirmed by Western blot analysis of primary gastric cancer tissues and cell lines. These data suggest that TBX3 overexpression may play a role in the development and progression of sporadic gastric cancers.

• Journal of Gastric Cancer
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• v.14 no.2
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• pp.67-86
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• 2014

Gastric cancer is one of the most common cancers in the world. Animal models have been used to elucidate the details of the molecular mechanisms of various cancers. However, most inbred strains of mice have resistance to gastric carcinogenesis. Helicobacter infection and carcinogen treatment have been used to establish mouse models that exhibit phenotypes similar to those of human gastric cancer. A large number of transgenic and knockout mouse models of gastric cancer have been developed using genetic engineering. A combination of carcinogens and gene manipulation has been applied to facilitate development of advanced gastric cancer; however, it is rare for mouse models of gastric cancer to show aggressive, metastatic phenotypes required for preclinical studies. Here, we review current mouse models of gastric carcinogenesis and provide our perspectives on future developments in this field.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.6
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• pp.3491-3497
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• 2013

Background: Gastric and esophageal cancers are among the most lethal human malignancies worldwide. Of all malignancies estimated in Iran (47,100), gastric and esophageal cancers were responsible for 7,800 and 3,500 deaths in 2008 respectively. The present study aimed to provide an image of patho-epidemiological characteristics with their trends during two past decades with emphasis on topographic, morphologic, and some demographic features. Materials and Methods: In a hospital-based retrospective study in 2009, all pathological reports from esophageal endoscopies and gastric biopsies through a 20 years period (1989-2008) were collected and analyzed in four interval periods(five years each). Also, all eligible samples in hospital archives were enrolled for further testing. Besides, demography, topography and morphology of all samples were determined and analyzed by statistical software. Results: No significant statistical difference was seen in frequency of espohageal and gastric tumors throughout the study. Esophageal cancer cases were older than gastric. Sex ratio was 2.33/1 and men had a higher rate of both esophageal and gastric tumors. Stomach cancer included 64.3% of all cases. Inferior third and end of esophagus were common locations for esophageal tumors whereas proximal stomach was common for gastric tumors. Squamous cell carcinoma and adenocarcinoma were common morphological types of tumors in esophagus and stomach respectively. Conclusions: Morphological trends showed an increase of esophageal adenocarcinoma and diffuse/intestinal ratio in stomach cancers. Trends in incidence from gastric cancer decreased based on topographic studies but we could not find a topographical trend toward cadia.