Achalasia is a relatively rare esophageal motility disorder characterized by incomplete relaxation of the lower esophageal sphincter (LES) and lack of esophageal peristalsis.1 The disorder has an incidence of approximately 1 to 1.6 per 100,000 people.2 Men, women, and all races are affected equally. Most patients will clinically present with dysphagia, regurgitation of solids or liquids, aspiration, and/or heartburn between the ages of 30 and 60.
http://www.cancertherapyadvisor.com/gastrointestinal-cancers/esophageal-cancer-risk-achalasia-treatment/article/548159/
Achalasia and the Risk for Esophageal Cancer