ENDOSCOPIC DIAGNOSIS OF SUPERFICIAL BARRETT’S ESOPHAGEAL ADENOCARCINOMA

Abstract

The incidence of reflux esophagitis is increasing in Japan along with a gradual rise in esophageal adenocarcinoma cases originating from Barrett’s esophagus, which is closely related to reflux esophagitis. The prognosis of advanced esophageal adenocarcinoma is poor, and early detection using endoscopy is necessary to improve patient prognosis. Our nationwide multicenter survey showed that the endoscopic features of superficial adenocarcinomas were mostly reddish and elevated （or protruded）. More than two-thirds were localized on the anterior to right-side wall, mainly at the 2° position （the triad of superficial cancer）. However, diagnosing early-stage cancers occurring in Barrett’s esophagus with chronic inflammation is challenging using white-light endoscopy alone. Since the 2000s, several advanced endoscopic imaging techniques have emerged, and many reports have demonstrated their utility in the early detection of Barrett’s esophageal adenocarcinoma. This review summarizes the previous reports on practically applicable advanced endoscopic diagnostic techniques in Japan, such as image-enhanced endoscopy （virtual chromoendoscopy） and acetic acid-enhanced endoscopy. These techniques have demonstrated high diagnostic performance and are recommended for use in combination with white-light endoscopy for the surveillance of Barrett’s esophagus in recent Western guidelines. Artificial intelligence-based diagnostic systems have also been developed in recent years, and their usefulness in detecting superficial adenocarcinomas and diagnosing their submucosal invasion has been reported; however, their applicability in general clinical practice remains unclear. We also discuss the differences between Japan and the West, including pathological diagnosis and the recently reported surveillance method based on the incidence of cancer development in Barrett’s esophagus in the Japanese population. Furthermore, we introduce the magnifying endoscopic classification （JES-BE classification） proposed by the Japan Esophageal Society, which provides endoscopic images to support clinical evaluation.