Low prevalence of submucosal invasive carcinoma at esophagectomy for high-grade dysplasia or intramucosal adenocarcinoma in Barrett's esophagus: a 20-year experience - Wang,V.S.; Hornick,J.L.; Sepulveda,J.A.; Mauer,R.; Poneros,J.M. (Gastrointest Endosc, 2009)