By Robert Preidt
The findings suggest that in the United States, a third of esophageal cancer cases -- that's about 5,600 per year -- could be prevented if people maintained a healthy weight and didn't drink.
"Obesity is now linked to 11 types of cancer and alcohol links to six," she said in an institute news release. "We want individuals to know you can take important lifestyle steps to reduce risk for many kinds of cancer."
In the new report, experts at the AICR and the World Cancer Research Fund reviewed 46 studies involving more than 15 million adults, including 31,000 who developed esophageal cancer.
The analysis showed that for every 5-point increase in body mass index (BMI, an estimate of body fat based on weight and height), there is a 48 percent increased risk of esophageal adenocarcinoma, which generally develops in the lower esophagus. About 60 percent of esophageal cancer cases in the United States are adenocarcinomas.
To better understand BMI, a 5-foot-9 man weighing 150 pounds has a BMI of 22, but at 210 pounds his BMI rises to 31 -- over the threshold for obesity.
One cancer specialist wasn't surprised by the new findings.
"The tremendous rise in esophageal cancer has paralleled the obesity epidemic," said Dr. Anthony Starpoli, who helps direct esophageal endotherapy at Lenox Hill Hospital in New York City. "This study offers support to this observation."
Squamous cell esophageal cancer, which develops from the cells that line the esophagus, accounts for one-third of esophageal cancers in the United States, but is the most common type of esophageal worldwide.
"Alcohol could have a direct carcinogenic effect, or it could be that reflux being worsened by alcohol leads to more damage to the lining or inner wall of the esophagus," speculated Starpoli. Chronic acid reflux is a risk factor for esophageal cancer.
"And of course, the empty calories from alcohol contribute to obesity," Starpoli added.
Bender said these risks can be reduced.
"Making smart choices like limiting alcoholic drinks, eating more vegetables, beans and other plant foods, and boosting your activity with walking breaks are all ways to get on a path to lower cancer risk," Bender said.
Esophageal cancer is the sixth most common cause of cancer death worldwide, and the seventh leading cause of cancer death among U.S. men, the AICR said. Survival rates for this cancer are poor, because it's often diagnosed at a late stage.