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Background/Aims: Newly developed autofluorescence (AF) imaging (AFI) endoscopy can detect AF emitted by the gastrointestinal wall and may reliably detect tumors or inflammation that block AF. However, the efficacy of AFI endoscopy has not been evaluated for diagnosing the depth of tumor invasion in gastric cancer. Methods: AF endoscopic images were split into three bands (R, G and B) and expressed as grayscale values. AF indices, defined as the ratio of the G band image grayscale value to that of the R band, were calculated preoperatively. Correlations of AF indices with invasion depth and tumor thickness were assessed. AF indices were calculated preoperatively for 72 gastric cancer lesions without ulceration in 67 patients. The invasion grade of the lesions was classified histologically into 5 groups: M, SM, MP, SS and SE. Results: The mean tumor AF indices for each depth stage were 0.99, 0.77, 0.75, 0.74 and 0.61, respectively. A statistically significant difference was found between group M and the other groups. Conclusion: AFI endoscopy may reliably determine the depth of gastric cancer tumor invasion, although an expanded study comprised of larger numbers of subjects and different types of cancers may be required to clearly demonstrate its validity. Copyright © 2010 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background and Aims: Low-grade erosive esophagitis (i.e. Los Angeles grade A) is the most predominant type of esophagitis in Japan. It is unclear whether all the mucosal breaks detected by conventional endoscopy are indicative of esophageal mucosal erosion. Hospital-based, cross-sectional, cross-over, observational study was assigned to investigate the value of magnifying endoscopy for diagnosis of erosive esophagitis. Methods: From August to December 2006, 178 consecutive patients with upper gastrointestinal symptoms were enrolled at three university hospitals and one national medical center in western Japan. Before endoscopy, all participants were requested to answer questionnaires concerning their symptoms. Experienced endoscopists performed an endoscopic diagnosis of each patient first with a conventional standard view and then with a magnifying view. Endoscopic diagnostic concordance between conventional and magnifying endoscopic view for erosive esophagitis was calculated. Relationship between a variety of symptoms and erosive esophagitis was also evaluated. Results: Erosive esophagitis was identified using conventional and magnifying endoscopy in 14.6% and 17.4% of patients, respectively. Eleven false-negative and six false-positive diagnoses using conventional endoscopy occurred among the 178 enrolled patients. The weighted kappa value of diagnostic concordance for erosive esophagitis between the two endoscopic views was 0.76. The prevalence of erosive esophagitis in patients with reflux-, dysmotility-, and ulcer-like symptoms was 20.7%, 24.1%, and 15.2%, respectively. Conclusions: Magnifying endoscopy did not significantly improve the diagnostic sensitivity of erosive esophagitis over non-magnifying, conventional endoscopy. Erosive esophagitis was frequently identified in patients that did not have reflux symptoms. [ABSTRACT FROM AUTHOR]