That's according to a new Australian study published in tomorrow's advance online edition of the journal Gut.
The study included nearly 800 patients with esophageal cancer and 1,580 adults without esophageal cancer.
The researchers included David Whiteman, MBBS, PhD, of Australia's Brisbane Hospital.
They tracked BMI (body mass index, which compares height to weight) among people with and without esophageal cancer.
Compared with people with a normal BMI, esophageal cancer was up to six times as common among very obese people (BMI of at least 40) and about twice as likely among obese people (BMI of 30 or more).
Obesity and esophageal cancer were more strongly related in men than women and in people younger than 50 than in older adults.
The study doesn't prove that obesity directly causes esophageal cancer. But that possibility deserves further study, according to Whiteman and colleagues.