Dr Whiteman and colleagues from Australia measured the relative risks of adenocarcinomas of the esophagus and gastro-esophageal junction.
The researchers recorded measures of obesity, and their interactions with age, sex, gastro-esophageal reflux symptoms and smoking.
The team compared 367 patients with adenocarcinomas of the esophagus, 426 with adenocarcinoma of the gastro-esophageal junction, and 1580 control participants sampled from a population register.
|Risks associated with obesity were higher among men than women|
The team calculated the relative risk of adenocarcinoma of the esophagus or gastro-esophageal junction.
The researchers found that risks of esophageal adenocarcinoma increased monotonically with body mass index. Highest risks were seen for body mass index 40 kg/m2, compared with a body mass index of 18.5 to 24.9 kg/m2.
The team of researchers found that adjustment for gastro-esophageal reflux and other factors modestly attenuated risks.
The team observed that risks associated with obesity were substantially higher among men than women, and among those aged less than 50 years than those aged 50 years.
The researchers found that obese people with frequent symptoms of gastro-esophageal reflux had significantly higher risks than people with obesity but no reflux.
In addition, obese people with frequent reflux symptoms had higher risks than people with reflux but no obesity, consistent with a synergistic interaction between these factors.
Similar associations, but of smaller magnitude, were seen for gastro-esophageal junction adenocarcinomas.
Dr Whitemans' team concluded, "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."