RFA to Prevent Metachronous Squamous Neoplasia Recurrence After Complete Endoscopic Submucosal Dissection

Preemptive Radiofrequency Ablation for Esophageal Speckled Lugol Background Mucosa to Prevent Metachronous Neoplastic Recurrence After Complete Endoscopic Submucosal Dissection ~A Randomized Controlled Study

Esophageal cancer is a highly lethal disease, and its incidence is still increasing in the world. Recent advances in image-enhanced techniques such as Lugol chromoendoscopy and narrow band imaging, the number of patients with early esophageal squamous cell neoplasias (ESCNs) detected has markedly increased. Endoscopic submucosal dissection (ESD) enables en bloc resection of the neoplasia, and the resected specimen allows for a pathological assessment to evaluate the curability. However, the patients who received complete ESD for early ESCNs frequently developed metachronous recurrence. The cumulative metachronous recurrence rate at 5 years was 50%, and the mean annual incidence of newly diagnosed metachronous tumors was 10%. Among them, those with "speckled" lugol staining pattern over the esophageal background mucosa have the highest risk and should be seen as a precancerous lesion of ESCCs. This issue is gaining attention in the era of endoscopic treatment, but currently there was no appropriate strategy to prevent the tumor recurrence in these high-risk subjects.

Endoscopic radiofrequency ablation (RFA) is a rapidly evolving therapeutic modality, and recent studies have shown its efficacy and safety for eradicating for flat type early ESCNs. To search a best strategy for the prevention of ESCNs, the investigators thus propose a hypothesis that the preemptive RFA for esophageal "speckled" lugol background mucosa may prevent the metachronous neoplastic recurrence after complete endoscopic resection.

Inclusion Criteria:

• Adults with early stage ESCNs (squamous high grade dysplasia, carcinoma in situ, or T1N0M0 SCC) who were treated by endoscopic submucosal dissection.
• Lugol staining showed "speckled" (>10 small lugol-unstained lesions) pattern of background mucosa.

Exclusion Criteria:

• Having a history of incomplete endoscopic treatment, or complications during/after treatment (perforation, stricture).
• Having history of systemic chemotherapy or radiation therapy for esophagus or post esophagectomy.
• Life expectancy <2 yr.
• Decompensated cirrhosis (Child score B, C).
• Having large esophageal varices.
• Poor performance status (ECOG>2).