Vertical tumor-positive resection margins and the risk of residual neoplasia after endoscopic resection of Barrett's neoplasia: a nationwide cohort with pathology reassessment

Background This study evaluated the proportion of patients with residual neoplasia after endoscopic resection(ER) for Barrett's neoplasia with confirmed tumor-positive vertical resection margin (R1v). Methods This retrospective cohort study included patients undergoing ER for Barrett's neoplasia with histologically documented R1v since 2008 in the Dutch Barrett Ex-pert Centers. We defined R1v as cancer cells touching vertical resection margins and Rx as nonassessable margins. Re-assessment of R1v specimens was performed by experienced pathologists until consensus was reached regarding vertical margins. Results 101/110 included patients had macroscopically complete resections (17 T1a, 84 T1b), and 99/101 (98%)ER specimens were histologically reassessed, with R1v con-firmed in 74 patients (75%), Rx in 16%, and R0 in 9%. Presence/absence of residual neoplasia could be assessed in 66/74 patients during endoscopic reassessment (52) and/or in the surgical resection specimen (14), and 33/66 (50%) had residual neoplasia. Residual neoplasia detected during endoscopy was always endoscopically visible and biopsies from a normal-appearing ER scar did not detect additional neoplasia. Of 25 patients who underwent endoscopic follow-up (median 37 months [interquartile range 12-50]), 4developed local recurrence (16.0%), all detected as visible abnormalities. Conclusions After ER with R1v, 50% of patients had no residual neoplasia. Histological evaluation of ER margins appears challenging, as in this study 75% of documentedR1v cases were confirmed during reassessment. Endoscopic reassessment 8-12 weeks after ER seems to accurately detect residual neoplasia and can help to determine the most appropriate strategy for patients with R1v.