Patients with Barrett's esophagus (BE) have a change in the lining of the esophagus. The normal one the lining of the esophagus changes to a lining similar to that of the intestine. The new mucosa has increased the risk of developing cancer. Usually this type of cancer is detected in a late phase and the patients' survival is low (less than 25% at 5 years). In daily practice, we strive to detect early cancerous lesions in order to treat them and cure them the patients. It has been widely demonstrated in BE patients that if cancer or precursor lesions are detected in an early phase, patients can be cured with endoscopic treatment. Endoscopic treatment of BE is based on endoscopic resection of the lesions / early cancer. After resection, patients have a 20-47% risk of developing cancer later in the remaining Barrett's esophagus. So there is a need to remove the remaining Barrett's mucosa that has not been resected. Several techniques can be used for removal of remaining BE: radiofrequency ablation, argon plasma, cryotherapy or endoscopic resection. The goal is to after resection of cancer and removal of residual Barrett's mucosa, a normal esophageal epithelium will cover the esophagus and dramatically reduce the risk for cancer development. The most widely used strategy for removal of residual Barrett's mucosa is radiofrequency ablation. It is an easy technique to perform, but it is hindered by some factors: 1) it requires several treatment sessions; 2) is associated with complications in 11% of patients, such as severe pain, bleeding, stricture and perforation 3) Barrett's mucosal glands may grow under the new epithelium after treatment; 4) there is no histological assessment of what is ablated; 5) there is a need for continuous follow-up; 6) it there are high costs associated with this strategy; 7) This approach may cause physical and physiological burdens on patients due to continuous follow-up and lack of complete histological assessment. Endoscopic submucosal dissection (ESD) is an advanced endoscopic technique that enables resection of lesions or cancer in one piece and has been used extensively along the gastrointestinal tract. Studies have showed good effect of ESD for neoplastic BE. Karolinska has a lot of experience with ESD and has one of the largest the cohorts of ESD on BE patients. ESD of BE can be associated with complications such as bleeding and perforation in 2-3% in most published studies and in less than 1% each in our series. Another complication that can occur is narrowing of the the esophagus during the healing process after ESD. That risk was historically high and increased with the increase in the size of the resected specimen. The high risk of crowding out was the main inhibiting factor the development of ESD in the esophagus. With the introduction of steroid therapy to prevent narrowing a paradigm shift was formed and the corresponding narrowing risk was drastically reduced to between 2-33% in according to the size of the resections. In our series of 132 ESDs on Barrett's esophagus, 103 cases corresponded resections up to 75% of the luminal(?) circumference of the esophagus, in these only 4/103 (3.9%) had strictures and all were successfully treated with endoscopic balloon dilatation. In the remaining 29 ESDs: included resection more than 75% of the luminal circumference. In these, there was narrowing in 10/29 cases, all patients was successfully treated with endoscopic treatment. So preventive measures and thorough follow-up are associated with good results and safety profile, even in large ESD on BE. Several years ago did not perform ESD for the treatment of BE, due to the need for skilled endoscopists and the potential the risks of this procedure such as bleeding, perforation and strictures. Full resection of the BE mucosa allows complete resection of all mucosa at risk, with complete histological assessment and virtually no risk of lesion presence in the margins or development of buried glands. It leads to complete removal of BE and may lead to the need for additional follow-up. With this study, we want to test the efficacy and safety of ESD for the removal of all Barrett's mucosa, instead of the more common approach of resection of Barrett's cancer followed by ablation of the remaining BE.