[Increased incidence of adenocarcinoma of the esophagus and cardia. Reflux and obesity are strong and independent risk factors according to the SECC study].

In a Swedish nationwide case-control study, gastroesophageal reflux and obesity were identified as strong and independent risk factors for esophageal adenocarcinoma. A moderately strong association was found with adenocarcinoma of the gastric cardia. No significant association was found with squamous cell carcinoma of the esophagus. With increasing duration and severity of reflux symptoms and with increasing body mass index (BMI) the risk increased in a dose-dependent manner. When combined, reflux symptoms and obesity entailed greatly increased risk estimates, with relative risks exceeding 100 compared with persons with neither reflux symptoms nor obesity. However, because adenocarcinoma of the esophagus and gastric cardia are rarities, the absolute risk of developing these tumors was still not high. Our calculations revealed that even in the group with the highest risk, endoscopic surveillance is not readily recommended. Possible reasons for the increasing incidence of adenocarcinoma of the esophagus include 1) a suspected increase in the prevalence of reflux disease; 2) the increasing prevalence of obesity reported in western populations; and 3) the widespread use of medications that relax the lower esophageal sphincter and might cause reflux. All of these hypotheses suffer from inconsistencies that need to be solved before any firm conclusions can be drawn concerning the reasons for the increasing incidence of esophageal adenocarcinoma.