Prospective Endoscopic Follow-up of Patients With Submucosal and High Risk Mucosal Esophageal Adenocarcinoma

Aim of this prospective multicenter study is to evaluate the safety of an endoscopic follow-up strategy in patients treated with endoscopic resection (ER) for submucosal or high-risk mucosal esophageal adenocarcinoma (T1bN0M0 or HR T1aN0M0 EAC).

Traditionally, the risk of lymph node metastasis associated with submucosal EAC was considered too high to offer patients endoscopic follow-up. Only in elderly patients with comorbidity, more often an endoscopic protocol is selected. However, the risk of lymph node metastasis associated with submucosal EAC is mainly based on surgical series. Recently a number of studies, which included patients treated endoscopically, were published indicating that the risk of lymph node metastasis may be much lower than generally assumed (1-5). Therefore, a less invasive and organ preserving approach may not only be an option in the frail and elderly, but for all patients with submucosal EAC's. Yet, no data exists on the risk of lymph node metastasis in high risk T1a EAC. The risk is assumed to be lower than for EACs invading into the submucosal layer. However, a recent retrospective analysis from our own research group shows that this risk may be higher than previously assumed (6). In this nationwide retrospective study, we analyzed lymph node metastasis rates and EAC related mortality rates concerning patients with high risk T1a, low risk T1b or high risk T1b EAC who received endoscopic treatment. The study was performed in 9 Barrett Expert Centers in the Netherlands (2008-2019). 120 patients were included in the analysis, and results showed the highest lymph node metastasis risk in the high risk T1a patient group. Aim of this multicenter study is to prospectively evaluate the safety of endoscopic follow-up in patients treated by endoscopic resection for submucosal (T1bN0M0) and high risk mucosal (T1aN0M0) EAC. High-resolution upper endoscopy with white-light endoscopy and narrow-band imaging supplemented with an EUS are performed every three months during the first two years after ER. After 1 year, a CT-thorax/abdomen will be performed to check for distant metastasis. During the third and fourth year of follow-up, EUS and upper endoscopy are performed every six months. From the fifth year on, EUS and upper endoscopy are performed annually.

Inclusion Criteria: * Patients with submucosal or high-risk mucosal EAC diagnosed in an ER specimen, by an expert gastrointestinal (GI) pathologists. * Signed informed consent. Exclusion Criteria: * Prior history of high-risk mucosal or ≥T1sm. * Synchronous esophageal squamous cell carcinoma. * Suspicion on lymph node metastasis or distant metastasis on EUS, ultrasound of the neck or CT-thorax-abdomen performed six weeks after ER during baseline measurement. * Tumor-positive deep resection margin (R1) in ER specimen. * Patients unable to give signed informed consent.