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

## TL;DR

Piecemeal endoscopic resection of early esophageal cancer is linked to higher recurrence risk, especially when over half the resected tissue contains cancer.

## Contribution

Identified a 50% cancer burden threshold in piecemeal resection specimens as a predictor of residual/recurrent cancer.

## Key findings

- Piecemeal resection (pEMR) was associated with higher recurrence rates compared to en-bloc resection.
- Cancer burden over 50% in pEMR specimens predicted residual/recurrent OAC in two cohorts.
- A 50% cutoff can guide post-resection follow-up and ablation decisions.

## Abstract

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.

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.

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).

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.

Summarize the established knowledge on this subject.◦Endoscopic resection (ER) is the standard curative treatment for early‐stage oesophageal adenocarcinoma (OAC), with piecemeal resection often performed for lesions larger than 15 mm without suspicion of submucosal invasion◦Piecemeal mucosal resection (pEMR) prevents confident assessment of lateral margins, making estimation of the risk of residual disease difficult◦Use of a piecemeal resection technique has been shown to correlate with the risk of recurrence of OAC◦Current guidelines recommend ablation of remaining Barrett's oesophagus post‐ER; however, ablation of residual undetected flat cancer can reduce chances of cureWhat are the significant and/or new findings of this study?◦Patients treated with pEMR have increased rates of recurrent neoplasia compared with those treated with en‐bloc resection◦The percentage of specimens containing cancer is an independent risk factor for residual and recurrent OAC following pEMR◦In two independent cohorts, patients with OAC in more than 50% of pEMR specimens showed increased rates of residual and recurrent OAC over follow‐up◦A cut‐off of 50% of pEMR specimens with OAC can be used to risk stratify patients and inform which patients should receive more careful follow up prior to ablation of the remaining Barrett's epithelium

Summarize the established knowledge on this subject.

Endoscopic resection (ER) is the standard curative treatment for early‐stage oesophageal adenocarcinoma (OAC), with piecemeal resection often performed for lesions larger than 15 mm without suspicion of submucosal invasion

Piecemeal mucosal resection (pEMR) prevents confident assessment of lateral margins, making estimation of the risk of residual disease difficult

Use of a piecemeal resection technique has been shown to correlate with the risk of recurrence of OAC

Current guidelines recommend ablation of remaining Barrett's oesophagus post‐ER; however, ablation of residual undetected flat cancer can reduce chances of cure

What are the significant and/or new findings of this study?

Patients treated with pEMR have increased rates of recurrent neoplasia compared with those treated with en‐bloc resection

The percentage of specimens containing cancer is an independent risk factor for residual and recurrent OAC following pEMR

In two independent cohorts, patients with OAC in more than 50% of pEMR specimens showed increased rates of residual and recurrent OAC over follow‐up

A cut‐off of 50% of pEMR specimens with OAC can be used to risk stratify patients and inform which patients should receive more careful follow up prior to ablation of the remaining Barrett's epithelium