Barrett's esophagus is a premalignant condition where the normal squamous epithelium of the esophagus is replaced by columnar epithelium, usually as a result of chronic gastroesophageal reflux disease. It is a risk factor for esophageal adenocarcinoma. Screening for Barrett's esophagus is recommended for men over 50 with chronic GERD symptoms. Treatment options for dysplasia include endoscopic ablation or resection. Esophageal cancer is often diagnosed via endoscopy and has a poor prognosis depending on stage. Risk factors include tobacco, alcohol, GERD, and obesity.