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.