Occurrence of metachronous or synchronous lesions after endoscopic treatment of gastric epithelia dysplasia- impact of histologic features of background mucosa

Aims: Endoscopic resection is a safe and effective method to treat gastric epithelia dysplasia (GED). However, the development of metachronous and synchronous lesions after treatment has become a major concern. In this study, we investigated clinicopathologic features of 105 GED lesions from endoscopic resections between January 2008 and December 2009. Our goal is to find histologic factors that predict synchronous and metachronous lesions after ESD treatment. We assessed the degree of intestinal metaplasia (IM) and atrophy, type of IM, presence of gastritis cystica profunda, and crypt dysplasia in the adjacent mucosa. Methods and results: We divided 105 GED lesions into three groups: a single group without metachronous or synchronous GED or adenocarcinoma (n = 35); a multiple synchronous group (n = 30, group with synchronous occurrence of GED or adenocarcinoma after treatment); and a multiple metachronous group (n = 40, group with metachronous occurrence of GED or adenocarcinoma after treatment). The multiple metachronous and synchronous groups showed larger sizes (p = 0.003) and higher grades (p = 0.021) as compared with the single group. Furthermore, marked IM and atrophy in adjacent mucosa were more easily seen in the multiple metachronous and synchronous groups as compared with the single group (p < 0.0001). Interestingly, the presence of incomplete type of IM (p = 0.025) and crypt dysplasia (p < 0.0001) in background mucosa was associated with occurrence of metachronous and synchronous lesions following endoscopic resection of GED. Conclusions: The histological features of background mucosa, such as intestinal metaplasia, atrophy, and crypt dysplasia could be used as indicators of occurrence of metachronous and synchronous lesions after endoscopic treatment of GED.