During the past decades, endoscopic resection techniques have gradually improved and gained more importance for the management of premalignant lesions and early cancers. These endoscopic resection techniques can be di...During the past decades, endoscopic resection techniques have gradually improved and gained more importance for the management of premalignant lesions and early cancers. These endoscopic resection techniques can be divided in 3 major groups: snare polipectomy, endoscopic mucosal resection(EMR) and endoscopic submucosal dissection(ESD). The use of submucosal injection is essential for the majority of EMR techniques and is an integral part of ESD,whereas during polipectomy it is not crucial in most cases except to prevent bleeding in large polyps and/or those with large stalks as an alternative to mechanical methods. Injection provides a lifting up effect of the lesion separating it from the muscular layer, thereby reducing thermal injury and the risk of perforation and bleeding while also facilitating en-bloc resection by improving technical feasibility. With this work, we aim to review the most common endoscopic resection techniques and the importance of submucosal injection in each one of them. For that, we present some of the most commonly used submucosal injection solutions, taking into account their advantages and disadvantages. We also discuss, based on current recommendations and our own experience, how and when to preform submucosal injection, depending on lesions features and endoscopic resection technique that′s being used, to assure complete resection and to prevent associated adverse events. Finally, we also present and discuss some new proposed submucosal injection solutions,endoscopic resection techniques and devices that may have a major impact on the future of therapeutic endoscopy.展开更多
AIM： To investigate the relationship between the -765G 〉 C COX-2 polymorphism and the development of different gastric lesions： atrophy or intestinal metaplasia and gastric adenocarcinoma. METHODS： A cross-section...AIM： To investigate the relationship between the -765G 〉 C COX-2 polymorphism and the development of different gastric lesions： atrophy or intestinal metaplasia and gastric adenocarcinoma. METHODS： A cross-sectional study was performed involving 320 Portuguese individuals （210 without evidence of neoplastic disease, 73 patients with gastric adenocarcinomas and 37 with atrophy or intestinal metaplasia） using a PCR-RFLP method.RESULTS： -765C allele was overrepresented in the patients with gastric adenocarcinoma （51%） when compared either with the control group （38%） or patients with atrophy or intestinal metaplasia （27%）. Callele was found to be very common in our population （0.22）, and a multivariate logistic regression analysis revealed nearly 3-fold increased risk for the progression to gastric adenocarcinoma in patients with atrophy or intestinal metaplasia carrying the -765C allele （OR = 2.67, 95% CI = 1.03-6.93; P = 0.04）.CONCLUSION： -765C carrier status should be considered as another susceptibility marker for gastric adenocarcinoma development in patients with atrophy or intestinal metaplasia.展开更多
The accepted paradigm for intestinal-type gastric cancer pathogenesis is a multistep progression from chronic gastritis induced by Helicobacter pylori(H. pylori) to gastric atrophy, intestinal metaplasia, dysplasia an...The accepted paradigm for intestinal-type gastric cancer pathogenesis is a multistep progression from chronic gastritis induced by Helicobacter pylori(H. pylori) to gastric atrophy, intestinal metaplasia, dysplasia and ultimately gastric cancer. The genetic and molecular mechanisms underlying disease progression are still not completely understood as only a fraction of colonized individuals ever develop neoplasia suggesting that bacterial, host and environmental factors are involved. Micro RNAs are noncoding RNAs that may influence H. pylori-related pathology through the regulation of the transcription and expression of various genes, playing an important role in inflammation, cell proliferation, apoptosis and differentiation. Indeed, H. pylori have been shown to modify micro RNA expression in the gastric mucosa and micro RNAs are involved in the immune host response to the bacteria and in the regulation of the inflammatory response. Micro RNAs have a key role in the regulation of inflammatory pathways and H. pylori may influence inflammation-mediated gastric carcinogenesis possibly through DNA methylation and epigenetic silencing of tumor suppressor micro RNAs. Furthermore, micro RNAs influenced by H. pylori also have been found to be involved in cell cycle regulation, apoptosis and epithelial-mesenchymal transition. Altogether, micro RNAs seem to have an important role in the progression from gastritis to preneoplastic conditions and neoplastic lesions and since each micro RNA can control the expression of hundreds to thousands of genes, knowledge of micro RNAs target genes and their functions are of paramount importance. In this article we present a comprehensive review about the role of micro RNAs in H. pylori gastric carcinogenesis, identifying the micro RNAs downregulated and upregulated in the infection and clarifying their biological role in the link between immune host response, inflammation, DNA methylation and gastric carcinogenesis.展开更多
AIM: To investigate the association between epidermal growth factor (EGF) +61A/G polymorphism and susceptibility to gastric cancer, through a cross-sectional study. METHODS: Polymerase chain reaction resctriction frag...AIM: To investigate the association between epidermal growth factor (EGF) +61A/G polymorphism and susceptibility to gastric cancer, through a cross-sectional study. METHODS: Polymerase chain reaction resctriction fragment lenght polymorphism analyses were used to genotype EGF +61 in 207 patients with gastric lesions (162 patients with gastric adenocarcinomas, 45 with atrophy or intestinal metaplasia) and 984 controls. All subjects were Caucasian. RESULTS: Genotype distribution was 23.5% for GG and 76.5% for GA/AA in the control group, 18.4% for GG and 68.6% for GA/AA in the entire group with gastric lesions and 17.9% for GG and 82.1% for GA/AA in the group with gastric adenocarcinoma. No statistically significant associations were found between EGF +61 variants and risk for developing gastric cancer [odds ratios (OR) = 1.41, 95% confidence intervals (CI): 0.90-2.21, P = 0.116]. However, the stratification of individuals by gender revealed that males carrying A alleles (EGF +61A/G or AA) had an increased risk for developing gastric cancer as compared to GG homozygous males (OR = 1.55, 95% CI: 1.05-2.28, P = 0.021). CONCLUSION: In summary, we found that males who were A carriers for EGF +61 had an increased risk for developing gastric cancer. This result may be explained by the suggestion that women secrete less gastric acid than men.展开更多
Toll-like receptors (TLR) are essential for Helicobacter pylori (Hp) recognition and subsequent innate and adaptive immunity responses. TLR2 appears to be the receptor responsible for most of the immunologic reaction ...Toll-like receptors (TLR) are essential for Helicobacter pylori (Hp) recognition and subsequent innate and adaptive immunity responses. TLR2 appears to be the receptor responsible for most of the immunologic reaction against Hp infection. However, TLR4, TLR9 and eventually TLR5 may also have a synergic effect with TLR2 against Hp. It has been shown that gastric Hp infection increases TLR expression in the gastric mucosa. Moreover, recent studies have shown that human gastric carcinogenesis is associated not only with increased expression of TLR but also with decreased expression of their inhibitors such as Toll-Interacting Protein (TOLLIP) and peroxisome proliferator-activated receptor (PPAR)-g. Indeed, gastric dysplasia and adenocarcinoma are associated with high expression levels of TLR and low levels of TOLLIP and PPAR-g, suggesting increased activation of these receptors throughout human gastric carcinogenesis. In this article we discuss how these novels findings could be used not only for the diagnosis and prognosis of gastric lesions associated with Hp infection but also for their treatment. Specifically, we discuss the potential use of TLR agonists in addition to antibiotics to improve eradication rates of Hp and of TLR antagonists to slow the progression of gastric preneoplastic lesions. We also discuss the potential value of TLR signalling blockers and quantification of tumoral TLR expression, respectively, in the treatment and prognosis of gastric cancer. In conclusion, TLRs can be an important link between Hp and the sequence of gastric carcinogenesis and they can be used as biomarkers of gastric carcinogenesis. In this article, future lines of investigation related with these novel scientific findings are proposed and discussed.展开更多
AIM： To study the role of an insertion/deletion polymorphism in the pepsinogen C （PGC） gene, an effective marker for terminal differentiation of the stomach mucosa, in the susceptibility to the development of gastr...AIM： To study the role of an insertion/deletion polymorphism in the pepsinogen C （PGC） gene, an effective marker for terminal differentiation of the stomach mucosa, in the susceptibility to the development of gastric lesions. METHODS： The study was performed with 99 samples of known gastric lesions and 127 samples without evidence of neoplastic disease. PCR was employed and the 6 polymorphic alleles were amplified： Allele 1 （510 bp）, Allele 2 （480 bp）, Allele 3/4 （450/460 bp）, Allele 5 （400 bp） and Allele 6 （310 bp）. RESULTS： Our results revealed that Allele 6 carriers seemed to have protection against the development of any gastric lesion （OR = 0.34; P 〈 0.001）, non-dysplastic lesions associated with gastric adenocarcinoma such as atrophy or intestinal metaplasia （OR = 0.28; P 〈 0.001） or invasive GC （OR = 0.39; P = 0.004）. CONCLUSION： Our study reveals that the Allele 6 carrier status has a protective role in the development of gastric lesions, probably due to its association with higher expression of PGC. Moreover, the frequency of Allele 6 carriers in the control group is far higher than that obtained in Asian populations, which might represent a genetic gap between Caucasian and Asian populations.展开更多
文摘During the past decades, endoscopic resection techniques have gradually improved and gained more importance for the management of premalignant lesions and early cancers. These endoscopic resection techniques can be divided in 3 major groups: snare polipectomy, endoscopic mucosal resection(EMR) and endoscopic submucosal dissection(ESD). The use of submucosal injection is essential for the majority of EMR techniques and is an integral part of ESD,whereas during polipectomy it is not crucial in most cases except to prevent bleeding in large polyps and/or those with large stalks as an alternative to mechanical methods. Injection provides a lifting up effect of the lesion separating it from the muscular layer, thereby reducing thermal injury and the risk of perforation and bleeding while also facilitating en-bloc resection by improving technical feasibility. With this work, we aim to review the most common endoscopic resection techniques and the importance of submucosal injection in each one of them. For that, we present some of the most commonly used submucosal injection solutions, taking into account their advantages and disadvantages. We also discuss, based on current recommendations and our own experience, how and when to preform submucosal injection, depending on lesions features and endoscopic resection technique that′s being used, to assure complete resection and to prevent associated adverse events. Finally, we also present and discuss some new proposed submucosal injection solutions,endoscopic resection techniques and devices that may have a major impact on the future of therapeutic endoscopy.
基金Supported by the Portuguese League Against Cancer (Liga Portuguesa Contra o Cancro-Núcleo Regional do Norte) and AstraZeneca Foundation
文摘AIM： To investigate the relationship between the -765G 〉 C COX-2 polymorphism and the development of different gastric lesions： atrophy or intestinal metaplasia and gastric adenocarcinoma. METHODS： A cross-sectional study was performed involving 320 Portuguese individuals （210 without evidence of neoplastic disease, 73 patients with gastric adenocarcinomas and 37 with atrophy or intestinal metaplasia） using a PCR-RFLP method.RESULTS： -765C allele was overrepresented in the patients with gastric adenocarcinoma （51%） when compared either with the control group （38%） or patients with atrophy or intestinal metaplasia （27%）. Callele was found to be very common in our population （0.22）, and a multivariate logistic regression analysis revealed nearly 3-fold increased risk for the progression to gastric adenocarcinoma in patients with atrophy or intestinal metaplasia carrying the -765C allele （OR = 2.67, 95% CI = 1.03-6.93; P = 0.04）.CONCLUSION： -765C carrier status should be considered as another susceptibility marker for gastric adenocarcinoma development in patients with atrophy or intestinal metaplasia.
文摘The accepted paradigm for intestinal-type gastric cancer pathogenesis is a multistep progression from chronic gastritis induced by Helicobacter pylori(H. pylori) to gastric atrophy, intestinal metaplasia, dysplasia and ultimately gastric cancer. The genetic and molecular mechanisms underlying disease progression are still not completely understood as only a fraction of colonized individuals ever develop neoplasia suggesting that bacterial, host and environmental factors are involved. Micro RNAs are noncoding RNAs that may influence H. pylori-related pathology through the regulation of the transcription and expression of various genes, playing an important role in inflammation, cell proliferation, apoptosis and differentiation. Indeed, H. pylori have been shown to modify micro RNA expression in the gastric mucosa and micro RNAs are involved in the immune host response to the bacteria and in the regulation of the inflammatory response. Micro RNAs have a key role in the regulation of inflammatory pathways and H. pylori may influence inflammation-mediated gastric carcinogenesis possibly through DNA methylation and epigenetic silencing of tumor suppressor micro RNAs. Furthermore, micro RNAs influenced by H. pylori also have been found to be involved in cell cycle regulation, apoptosis and epithelial-mesenchymal transition. Altogether, micro RNAs seem to have an important role in the progression from gastritis to preneoplastic conditions and neoplastic lesions and since each micro RNA can control the expression of hundreds to thousands of genes, knowledge of micro RNAs target genes and their functions are of paramount importance. In this article we present a comprehensive review about the role of micro RNAs in H. pylori gastric carcinogenesis, identifying the micro RNAs downregulated and upregulated in the infection and clarifying their biological role in the link between immune host response, inflammation, DNA methylation and gastric carcinogenesis.
基金Supported by The Portuguese League Against Cancer (Liga Portuguesa Contra o Cancro-Núcleo Regional do Norte) and AstraZeneca Foundation
文摘AIM: To investigate the association between epidermal growth factor (EGF) +61A/G polymorphism and susceptibility to gastric cancer, through a cross-sectional study. METHODS: Polymerase chain reaction resctriction fragment lenght polymorphism analyses were used to genotype EGF +61 in 207 patients with gastric lesions (162 patients with gastric adenocarcinomas, 45 with atrophy or intestinal metaplasia) and 984 controls. All subjects were Caucasian. RESULTS: Genotype distribution was 23.5% for GG and 76.5% for GA/AA in the control group, 18.4% for GG and 68.6% for GA/AA in the entire group with gastric lesions and 17.9% for GG and 82.1% for GA/AA in the group with gastric adenocarcinoma. No statistically significant associations were found between EGF +61 variants and risk for developing gastric cancer [odds ratios (OR) = 1.41, 95% confidence intervals (CI): 0.90-2.21, P = 0.116]. However, the stratification of individuals by gender revealed that males carrying A alleles (EGF +61A/G or AA) had an increased risk for developing gastric cancer as compared to GG homozygous males (OR = 1.55, 95% CI: 1.05-2.28, P = 0.021). CONCLUSION: In summary, we found that males who were A carriers for EGF +61 had an increased risk for developing gastric cancer. This result may be explained by the suggestion that women secrete less gastric acid than men.
文摘Toll-like receptors (TLR) are essential for Helicobacter pylori (Hp) recognition and subsequent innate and adaptive immunity responses. TLR2 appears to be the receptor responsible for most of the immunologic reaction against Hp infection. However, TLR4, TLR9 and eventually TLR5 may also have a synergic effect with TLR2 against Hp. It has been shown that gastric Hp infection increases TLR expression in the gastric mucosa. Moreover, recent studies have shown that human gastric carcinogenesis is associated not only with increased expression of TLR but also with decreased expression of their inhibitors such as Toll-Interacting Protein (TOLLIP) and peroxisome proliferator-activated receptor (PPAR)-g. Indeed, gastric dysplasia and adenocarcinoma are associated with high expression levels of TLR and low levels of TOLLIP and PPAR-g, suggesting increased activation of these receptors throughout human gastric carcinogenesis. In this article we discuss how these novels findings could be used not only for the diagnosis and prognosis of gastric lesions associated with Hp infection but also for their treatment. Specifically, we discuss the potential use of TLR agonists in addition to antibiotics to improve eradication rates of Hp and of TLR antagonists to slow the progression of gastric preneoplastic lesions. We also discuss the potential value of TLR signalling blockers and quantification of tumoral TLR expression, respectively, in the treatment and prognosis of gastric cancer. In conclusion, TLRs can be an important link between Hp and the sequence of gastric carcinogenesis and they can be used as biomarkers of gastric carcinogenesis. In this article, future lines of investigation related with these novel scientific findings are proposed and discussed.
基金Supported by the Portuguese League Against Cancer (Liga Por-tuguesa Contra o Cancro-Nucleo Regional do Norte) and Astra Zeneca Foundation
文摘AIM： To study the role of an insertion/deletion polymorphism in the pepsinogen C （PGC） gene, an effective marker for terminal differentiation of the stomach mucosa, in the susceptibility to the development of gastric lesions. METHODS： The study was performed with 99 samples of known gastric lesions and 127 samples without evidence of neoplastic disease. PCR was employed and the 6 polymorphic alleles were amplified： Allele 1 （510 bp）, Allele 2 （480 bp）, Allele 3/4 （450/460 bp）, Allele 5 （400 bp） and Allele 6 （310 bp）. RESULTS： Our results revealed that Allele 6 carriers seemed to have protection against the development of any gastric lesion （OR = 0.34; P 〈 0.001）, non-dysplastic lesions associated with gastric adenocarcinoma such as atrophy or intestinal metaplasia （OR = 0.28; P 〈 0.001） or invasive GC （OR = 0.39; P = 0.004）. CONCLUSION： Our study reveals that the Allele 6 carrier status has a protective role in the development of gastric lesions, probably due to its association with higher expression of PGC. Moreover, the frequency of Allele 6 carriers in the control group is far higher than that obtained in Asian populations, which might represent a genetic gap between Caucasian and Asian populations.
