METHODS
Patients were identified by searching for “intramucosal carcinoma” from single-center hospital-wide pathology specimen database. Institutional ethics committee approval was sought and obtained. Results were hand-searched to identify all consecutive patients either undergoing EMR treatment or esophagectomy for intramucosal carcinoma from July 2005 to July 2013. Patients with invasive disease not amenable to endoscopic treatment (deeper than T1sm1 or node positive) were excluded. Results were then cross-referenced with a prospectively collected endoscopic procedures database (Clinical Outcomes Research Initiative (CORI), Portland, OR). This was supplemented with retrospective patient chart review from electronic records for endoscopy, operative, pathological, and clinic reports up to a total follow up time of 5 years.