Cancer Burden on Piecemeal Endoscopic Resection of Early Adenocarcinoma in Barrett's Oesophagus Correlates With the Risk of Neoplastic Recurrence.

BACKGROUND AND STUDY AIMS: Endoscopic resection (ER) is curative for early-stage oesophageal adenocarcinoma (OAC) without high-risk features. Piecemeal endoscopic mucosal resection (pEMR) prevents assessment of lateral margins, complicating risk estimation for neoplastic recurrence. We investigated the risk factors for residual and recurrent OAC post-pEMR. METHODS: We performed a longitudinal study of two independent patient cohorts: the test cohort who underwent piecemeal or en-bloc ER (n = 140) and the validation cohort who underwent pEMR only (n = 89). Inclusion criteria were: OAC stage T1a or low-risk T1b, no lympho-vascular invasion, and R0 resection. The primary outcome was residual OAC at first post-ER endoscopy, and secondary outcomes were residual neoplasia (high-grade dysplasia and/or OAC), recurrence of neoplasia at any post-ER endoscopy, and remission of neoplasia, dysplasia and metaplasia at most recent endoscopy. RESULTS: In the test cohort, the incidence of neoplastic recurrence was higher in patients treated with pEMR (n = 54, 49%) versus en-bloc ER (n = 7, 23%) (p = 0.021). The percentage of pEMR specimens with OAC was an independent risk factor for residual OAC at the first post-pEMR endoscopy (OR for a 10% increase = 1.24, CI = 1.03-1.51, p = 0.025). A 50% cut-off of pEMR specimens with OAC was optimal to predict residual OAC (specificity = 0.68, sensitivity = 0.63). Rates of residual (p = 0.039) and recurrent (p = 0.0052) OAC were higher when > 50% of pEMR specimens were involved by OAC. In the validation cohort, recurrent OAC was also more frequent when cancer burden was > 50% (p = 0.013). CONCLUSIONS: High cancer burden on pEMR specimens correlates with the risk of residual OAC. Post-pEMR site check before endoscopic ablation is recommended if more than 50% of pEMR specimens show OAC.