RT Journal Article SR Electronic T1 Combined effects of obesity, acid reflux and smoking on the risk of adenocarcinomas of the oesophagus JF Gut JO Gut FD BMJ Publishing Group Ltd and British Society of Gastroenterology SP 173 OP 180 DO 10.1136/gut.2007.131375 VO 57 IS 2 A1 D C Whiteman A1 S Sadeghi A1 N Pandeya A1 B M Smithers A1 D C Gotley A1 C J Bain A1 P M Webb A1 A C Green A1 for the Australian Cancer Study YR 2008 UL http://gut.bmj.com/content/57/2/173.abstract AB Objective: To measure the relative risks of adenocarcinomas of the oesophagus and gastro-oesophageal junction associated with measures of obesity, and their interactions with age, sex, gastro-oesophageal reflux symptoms and smoking.Design and setting: Population-based case–control study in Australia.Patients: Patients with adenocarcinomas of the oesophagus (n = 367) or gastro-oesophageal junction (n = 426) were compared with control participants (n = 1580) sampled from a population register.Main outcome measure: Relative risk of adenocarcinoma of the oesophagus or gastro-oesophageal junction.Results: Risks of oesophageal adenocarcinoma increased monotonically with body mass index (BMI) (ptrend <0.001). Highest risks were seen for BMI ⩾40 kg/m2 (odds ratio (OR) = 6.1, 95% CI 2.7 to 13.6) compared with “healthy” BMI (18.5–24.9 kg/m2). Adjustment for gastro-oesophageal reflux and other factors modestly attenuated risks. Risks associated with obesity were substantially higher among men (OR = 2.6, 95% CI 1.8 to 3.9) than women (OR = 1.4, 95% CI 0.5 to 3.5), and among those aged <50 years (OR = 7.5, 95% CI 1.7 to 33.0) than those aged ⩾50 years (OR = 2.2, 95% CI 1.5 to 3.1). Obese people with frequent symptoms of gastro-oesophageal reflux had significantly higher risks (OR = 16.5, 95% CI 8.9 to 30.6) than people with obesity but no reflux (OR = 2.2, 95% CI 1.1 to 4.3) or reflux but no obesity (OR = 5.6, 95% 2.8 to 11.3), consistent with a synergistic interaction between these factors. Similar associations, but of smaller magnitude, were seen for gastro-oesophageal junction adenocarcinomas.Conclusions: Obesity increases the risk of oesophageal adenocarcinoma independently of other factors, particularly among men. From a clinical perspective, these data suggest that patients with obesity and frequent symptoms of gastro-oesophageal reflux are at especially increased risk of adenocarcinoma.