Achalasia and esophageal cancer: risks and links

Esophageal cancer affects more than 4,50,000 persons worldwide, and its incidence has increased in recent years. It is the eighth most common cancer across the globe. The main histologic types are esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EA), and their associated risk factors are well known. Achalasia, an idiopathic esophageal disorder that conditions aperistalsis and the absence of lower esophageal sphincter relaxation, stands out among them. The prevalence of ESCC in subjects with esophageal achalasia is 26 in every 1,000 cases, whereas the prevalence of EA is 4 in every 1,000. Patients with achalasia have a 50 times higher risk of presenting with ESCC than the general population, and the disease manifests 20-25 years after achalasia symptom onset. Multiple mechanisms are related to the development of ESCC in achalasia, and they include bacterial overgrowth, food stasis, genetic alterations, and chronic inflammation. Regarding the risk of EA in achalasia patients, most cases are associated with Barrett's esophagus, due to uncontrolled chronic acid reflux. Given that achalasia is a well-established factor for ESCC/EA, clinicians must be aware of said associations to enable the development of programs for the prevention and opportune detection of these cancers in patients with achalasia.