Risk factors for oesophageal cancer.

The two main histological subtypes of oesophageal cancer, squamous cell carcinoma and adenocarcinoma, have distinct risk factor profiles. For oesophageal squamous cell carcinoma, tobacco smoking and excess alcohol use are the main risk factors. For adenocarcinoma, gastro-oesophageal reflux disease and obesity are main risk factors, whereas tobacco smoking is a moderately strong risk factor and infection with Helicobacter pylori decreases the risk. Dietary factors may influence the risk of both types of oesophageal cancer. Genetic factors are involved in the aetiology, but their influence is generally low. The striking male predominance in oesophageal adenocarcinoma is unexplained, although sex hormones may play a role. Risk prediction models combining information on multiple risk factors have shown promising potential in identifying high-risk individuals for targeted prevention and early detection, which should prompt further studies. More high-quality research efforts are warranted for better understanding of the aetiology of oesophageal cancer, particularly in developing countries.