Clinical Features of False-Negative Early Gastric Cancers: A Retrospective Study of Endoscopic Submucosal Dissection Cases

BACKGROUND: We frequently encounter early gastric cancer (EGC) that could not be detected in the previous esophagogastroduodenoscopy even if the procedure was annually performed. However, little evidence exists regarding the characteristics of false-negative EGCs. Our aim was to reveal the clinical features of false-negative EGCs. METHODS: We retrospectively reviewed cases of endoscopic submucosal dissection (ESD) for EGCs in Fukuchiyama City Hospital between January 2013 and May 2019. False-negative EGCs were defined as EGCs within 3 years of negative endoscopy. We evaluated the clinical characteristics of false-negative and initially detected EGCs and the difference in the detected and last missed endoscopy in false-negative EGCs. The miss rates of false-negative EGCs were compared between trainees (nonboard-certified endoscopists) and experienced endoscopists (board-certified endoscopists); thereafter, the characteristics of false-negative EGCs missed by trainees were investigated. RESULTS: Of 219 cases, 119 were classified as false-negative EGCs. False-negative EGCs were characterized as smaller lesions, which presented with normal color or gastritis-like appearance, and were diagnosed after ESD and H. pylori eradication (P < 0.01). The rate of trainees in the last missed endoscopy was significantly higher than that in the detected endoscopy. The miss rate of false-negative EGC by trainees was higher than that of experienced endoscopists but not significantly different (0.70% vs. 0.57%, P = 0.08). The false-negative EGCs missed by trainees were characterized as reddish or well-differentiated lesions, which were located in the lower or lesser curvature of the stomach (P < 0.05). CONCLUSION: The characteristics of false-negative EGCs were similar to those of H. pylori-eradicated EGC. Procedures with shortened examination time and those performed by trainees were risk factors of missing false-negative EGCs. Trainees should pay attention to reddish or well-differentiated EGCs located in the lower or lesser curvature of the stomach.