Clinical and Histopathological Features of the Differentiated Type of Early Gastric Cancer with an Unclear Lateral Demarcation

Abstract

<b><i>Introduction:</i></b> Magnifying endoscopy with narrow-band imaging (M-NBI) is useful for determining lateral demarcation of early gastric cancers; however, this is sometimes difficult. Features related to an unclear lateral demarcation remain unknown. We evaluated the clinical and histopathological features of early gastric cancers with unclear lateral demarcation on M-NBI. <b><i>Methods:</i></b> This single-center, retrospective, cohort study analyzed early gastric cancer treated by endoscopic submucosal dissection between January 2013 and August 2015. We evaluated the clinicopathological and immunohistochemical features using anti-p53, anti-Ki-67, anti-MUC5AC, anti-MUC6, anti-MUC2, and anti-CD10 antibody staining. We compared the lateral demarcation between the demarcation clear (DC) and the demarcation unclear (DU) lesions by using M-NBI. <b><i>Results:</i></b> A total of 224 differentiated adenocarcinomas (DU group: 18 lesions; DC group: 206 lesions) were analyzed. A history of successful <i>Helicobacter pylori</i> eradication was significantly more frequent in the DU group (<i>p</i> = 0.001). We examined the tissues of 72 lesions (DU group: 18 lesions, DC group: 54 lesions [randomly selected]) immunohistochemically. The nonneoplastic superficial epithelium was observed more frequently in the DU group as compared to in the DC group (<i>p</i> = 0.006). Additionally, compared to the DC group, the DU group showed a significantly higher expression of the gastric phenotype markers (<i>p</i> = 0.023) and had lower p53 scores (<i>p</i> < 0.001) and Ki-67 labeling indexes (<i>p</i> = 0.029). Multivariate analysis revealed the nonneoplastic superficial epithelium and a low p53 score as the significant independent variables associated with an unclear lateral demarcation on M-NBI. <b><i>Conclusions:</i></b> The nonneoplastic superficial epithelium and a low p53 score were associated with difficulties in determining the lateral demarcation in early gastric cancers on M-NBI.