2021 Volume 59 Issue 2 Pages 172-184
Objective: To determine the causes of false-negative diagnoses of gastric cancer to improve the accuracy of endoscopy.
Subjects and methods: At our institution, 1,088 cases of gastric cancer were diagnosed between April 2011 and March 2017. Over a 3-year period after screening endoscopy, we retrospectively analyzed 211 false-negative cases.
Results: Of the enrolled patients, 168 were males and 43 were females. Their mean age was 70±6.0 years. Forty-five, 102, and 64 lesions were observed in the upper, middle, and lower regions of the stomach. The mean tumor diameter was 15±13 mm. Further, 161, 40, and 10 lesions were diagnosed as mucosal cancer, submucosal cancer, and advanced cancer, respectively. The early cancer and mucosal cancer rates were 95.2% and 76.3%, respectively. At the three endoscopy intervals of up to 1 year, 1-2 years, and 2-3 years, the early cancer rates were 99.1%, 97.1%, and 73.1%, respectively, and the mucosal cancer rates were 81.2%, 76.4%, and 53.8%, respectively. The early cancer and mucosal cancer rates at the endoscopy interval of 2-3 years were significantly lower than those at the endoscopy intervals of up to 1 year and 1-2 years. For the upper, middle, and lower regions of the stomach, the early cancer rates were 86.7%, 97.1%, and 98.4%, respectively, and the mucosal cancer rates were 51.1%, 82.4%, and 84.4%, respectively. The early and mucosal cancer rates for the upper region of the stomach were significantly lower than those for the middle and lower regions. After analyzing previous endoscopic images, 50 false-negative cases involving the submucosal and deeper layers were classified as follows: eight cases of poorly observed lesions, 20 cases of poorly detected lesions, and 22 cases of lesions that were difficult to detect. More careful observation and detection were required for lesions in the upper region of the stomach as five lesions were poorly observed and 11 lesions were difficult to detect in this region.
Conclusions: To improve the accuracy of endoscopy, it is important to reassess gastric cancer cases using comprehensive endoscopy.
