Achalasia and Risk of Esophageal Squamous Cell Carcinoma and Adenocarcinoma in a Multinational Study.

Achalasia is strongly linked to esophageal squamous cell carcinoma, with an odds ratio of 9.46, but its connection to adenocarcinoma is weaker and largely explained by GERD.

• Why it matters: Understanding these associations is crucial because previous studies lacked sufficient adjustment for main risk factors like smoking, alcohol, and GERD, leading to uncertain conclusions about achalasia's role in esophageal cancers.
• What they did: A large multinational case-control study analyzed 35,604 esophageal cancer cases and over 350,000 controls from five Nordic countries, using national health registry data and adjusting for key risk factors.
• The result: Achalasia significantly increases the risk of squamous cell carcinoma, especially after treatment, while its link to adenocarcinoma diminishes after accounting for GERD, informing targeted prevention strategies.