Lugol Chromoendoscopy Detects Esophageal Dysplasia With Low Levels of Sensitivity in a High-Risk Region of China

Abstract

Chromoendoscopy with Lugol dye is used to screen for early-stage esophageal squamous dysplasia (ESD) and esophageal cancer. However, the sensitivity with which Lugol chromoendoscopy detects ESD or esophageal cancer has not been fully assessed in large populations in China. From 2012 to 2016, a total of 15,264 residents in rural Hua County, Henan Province, which is a high-incidence area of esophageal cancer in China, were screened by Lugol chromoendoscopy. Biopsies were collected from endoscopically visualized lesions, identified before and after Lugol chromoendoscopy, and analyzed histologically. Biopsies were also collected from standard sites in the esophagus (28 and 33 cm distal to the incisors) if no abnormalities were found. We calculated the sensitivity with which Lugol chromoendoscopy detects esophageal dysplasia and carcinoma, using findings from biopsy analysis as the reference standard. A total 586 participants were found by biopsy analysis to have ESD or more severe lesions. After endoscopy images were reviewed twice, Lugol chromoendoscopy sensitivity values for the detection of mild, moderate, and severe dysplasia, and esophageal cancer, were 45.9%, 55.3%, 87.0%, and 97.7%, respectively. ESDs were most frequently missed by Lugol chromoendoscopy in younger patients and men with moderate levels of dysplasia. In a screening analysis of a general population in China, we found Lugol chromoendoscopy to identify individuals with ESD with lower levels of sensitivity (46%-87%) than previously believed, although it identified patients with esophageal cancer with almost 98% sensitivity. Prospective studies are needed to evaluate the clinical significance of esophageal lesions that are not detected by endoscopy.