BACKGROUND: In previous studies in the high-risk population of Linxian, China, high-grade (moderate + severe) squamous dysplasia (HGD) and invasive squamous cancer (CA) of the esophagus have been associated with endoscopically visible lesions that could be targeted for biopsy. This study asked whether spraying the mucosa with Lugol's iodine solution, which stains normal epithelium brown but leaves dysplasia and cancer unstained, could improve endoscopic detection and localization of these lesions. METHODS: 223 Linxian adults were endoscoped. All visible lesions were described and photographed before and after staining with 1.2% Lugol's iodine solution. All unstained lesions (USLs) and representative control areas of stained mucosa were biopsied. RESULTS: 253 USLs and 255 control sites were biopsied. 91 biopsy sites contained HGD and 20 contained CA. Before staining, the sensitivity of visible lesions for identifying HGD and CA was 63%, and the specificity was 79%. After staining, the sensitivity of USLs for identifying HGD and CA was 96%, and the specificity was 64%. 100/111 (90%) of the HGD and CA lesions were larger or more clearly defined after staining. The diagnostic lesions in 16/30 (53%) of the patients with moderate dysplasia, 8/34 (24%) of the patients with severe dysplasia, and 0/19 (0%) of the patients with invasive cancer were identified only after staining. CONCLUSIONS: Lugol's iodine staining improved endoscopic detection and localization of HGD and CA in these patients. This simple technique is highly sensitive for identifying these precursor and early invasive squamous lesions. IMPLICATIONS: Accurate visualization of HGD and CA may allow endoscopic screening of high-risk individuals and may enable focal endoscopic therapies to eradicate these lesions. Such visualization may also allow endoscopic protocols to accurately evaluate intervention studies that use squamous dysplasia as an intermediate endpoint.
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging