Since the esophagus is easily accessible with endoscopy, early diagnosis and curative treatment of esophageal cancer is possible. However, diagnosis is often delayed because symptoms are not specific during early stages of tumor development. The onset of dysphagia is associated with advanced disease, and fewer than 15% of patients survive for 5 years. Population screening by endoscopy is not cost effective, but a number of alternative imaging and cell analysis technologies are under investigation.