Gastric cancer is believed to result in part from the accumulation of multiple genetic alterations leading to oncogeneoverexpression and tumor suppressor loss. Epigenetic alterations as a distinct and crucial mechanis...Gastric cancer is believed to result in part from the accumulation of multiple genetic alterations leading to oncogeneoverexpression and tumor suppressor loss. Epigenetic alterations as a distinct and crucial mechanism to silence a varietyof methylated tissue-specific and imprinted genes, have been extensively studied in gastric carcinoma and play impor-tant roles in gastric carcinogenesis. This review will briefly discuss the basic aspects of DNA methylation and CpGisland methylation, in particular the epigenetic alterations of certain critical genes implicated in gastric carcinogenesisand its relevance of clinical implications.展开更多
AIM:To investigate a classification of endocytoscopy(ECS)images in Barrett’s esophagus(BE)and evaluate its diagnostic performance and interobserver variability.METHODS:ECS was applied to surveillance endoscopic mucos...AIM:To investigate a classification of endocytoscopy(ECS)images in Barrett’s esophagus(BE)and evaluate its diagnostic performance and interobserver variability.METHODS:ECS was applied to surveillance endoscopic mucosal resection(EMR)specimens of BE ex-vivo.The mucosal surface of specimen was stained with 1%methylene blue and surveyed with a catheter-type endocytoscope.We selected still images that were most representative of the endoscopically suspect lesion and matched with the final histopathological diagnosis to accomplish accurate correlation.The diagnostic performance and inter-observer variability of the new classification scheme were assessed in a blinded fashion by physicians with expertise in both BE and ECS and inexperienced physicians with no prior exposure to ECS.RESULTS:Three staff physicians and 22 gastroenterology fellows classified eight randomly assigned unknown still ECS pictures(two images per each classification)into one of four histopathologic categories as follows:(1)BEC1-squamous epithelium;(2)BEC2-BE without dysplasia;(3)BEC3-BE with dysplasia;and(4)BEC4-esophageal adenocarcinoma(EAC)in BE.Accuracy of diagnosis in staff physicians and clinical fellows were,respectively,100%and 99.4%for BEC1,95.8%and83.0%for BEC2,91.7%and 83.0%for BEC3,and95.8%and 98.3%for BEC4.Interobserver agreement of the faculty physicians and fellows in classifying each category were 0.932 and 0.897,respectively.CONCLUSION:This is the first study to investigate classification system of ECS in BE.This ex-vivo pilot study demonstrated acceptable diagnostic accuracy and excellent interobserver agreement.展开更多
文摘Gastric cancer is believed to result in part from the accumulation of multiple genetic alterations leading to oncogeneoverexpression and tumor suppressor loss. Epigenetic alterations as a distinct and crucial mechanism to silence a varietyof methylated tissue-specific and imprinted genes, have been extensively studied in gastric carcinoma and play impor-tant roles in gastric carcinogenesis. This review will briefly discuss the basic aspects of DNA methylation and CpGisland methylation, in particular the epigenetic alterations of certain critical genes implicated in gastric carcinogenesisand its relevance of clinical implications.
文摘AIM:To investigate a classification of endocytoscopy(ECS)images in Barrett’s esophagus(BE)and evaluate its diagnostic performance and interobserver variability.METHODS:ECS was applied to surveillance endoscopic mucosal resection(EMR)specimens of BE ex-vivo.The mucosal surface of specimen was stained with 1%methylene blue and surveyed with a catheter-type endocytoscope.We selected still images that were most representative of the endoscopically suspect lesion and matched with the final histopathological diagnosis to accomplish accurate correlation.The diagnostic performance and inter-observer variability of the new classification scheme were assessed in a blinded fashion by physicians with expertise in both BE and ECS and inexperienced physicians with no prior exposure to ECS.RESULTS:Three staff physicians and 22 gastroenterology fellows classified eight randomly assigned unknown still ECS pictures(two images per each classification)into one of four histopathologic categories as follows:(1)BEC1-squamous epithelium;(2)BEC2-BE without dysplasia;(3)BEC3-BE with dysplasia;and(4)BEC4-esophageal adenocarcinoma(EAC)in BE.Accuracy of diagnosis in staff physicians and clinical fellows were,respectively,100%and 99.4%for BEC1,95.8%and83.0%for BEC2,91.7%and 83.0%for BEC3,and95.8%and 98.3%for BEC4.Interobserver agreement of the faculty physicians and fellows in classifying each category were 0.932 and 0.897,respectively.CONCLUSION:This is the first study to investigate classification system of ECS in BE.This ex-vivo pilot study demonstrated acceptable diagnostic accuracy and excellent interobserver agreement.
