Patients with MGIN, HGIN or flat-type early SCCA of the esophagus will be treated on 3 month intervals with Radiofrequency Ablation (RFA) until complete eradication (CR: no MGIN or worse in the biopsies) will be achieved. All patients will undergo an endoscopy at 12 months after baseline, and the patients with CR will undergo annual endoscopy with biopsies for 5 years.