Role of digital chromoendoscopy and confocal laser endomicroscopy for gastric intestinal metaplasia and cancer surveillance

In Japan and countries such as South Korea and Taiwan, China, the standard technique for detecting early gastric cancer (EGC) is chromoendoscopy. This technique involves a magnified endoscope and the use of an indigo-carmine spray to distinguish between EGC and non-EGC areas. However, this technique is not widely adopted in many parts of the world. One important reason for limited use is that this technique needs an experienced endoscopist to interpret the images during the procedure. In addition, the sensitivity for detecting gastric intestinal metaplasia (GIM), a precancerous lesion of EGC, is graded as suboptimal. Moreover, the requirement of a cumbersome spraying method is inconvenient and needs preparation time. Easier digital chromoendoscopy techniques, such as Narrow-band Imaging and Flexible spectral Imaging Color Enhancement, have been reported to facilitate targeted GIM and EGC biopsy. They provide higher sensitivities over conventional white light endoscopy. Recently, the novel technology of confocal laser endomicroscopy has been introduced as a high-magnification (1000 ×) real-time evaluation for many early gastrointestinal (GI) cancers and precancerous GI lesions, including colonic polyp, Barrett’s esophagus, and GIM. The advantage of this technique is that it can be used as an in vivo confirmation of the presence of GIM and EGC during endoscopic surveillance. This review aims to explain the current information on the usefulness of digital chromoendoscopy and confocal laser endomicroscopy for evaluating GIM and EGC during endoscopic surveillance and the possible future role of these techniques for GI cancer screening programs.