MADISON, Wis. -- People who drink two or more sodas each week can increase their risk of pancreatic cancer almost two-fold, according to a new study in Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research.

Pancreatic cancer is one of most deadly forms of cancer. Only 5 percent of those with the disease survive more than five years beyond diagnosis.

Mark Pereira, study author and associate professor at the University of Minnesota, said people who have soft drinks on a regular basis already tend to have a poor behavioral profile, but sugary soft drinks may have a unique effect on pancreatic cancer.

"The high levels of sugar in soft drinks may be increasing the level of insulin in the body, which we think contributes to pancreatic cancer cell growth," he said in a statement on the University of Minnesota’s web site.

The study followed more than 60,000 people in Singapore for 14 years. There were 140 cases of pancreatic cancer in the group during that time, less than 2 percent of the people studied. But the rate of pancreatic cancer was 87 percent higher among people who drank at least two soft drinks a week, with most averaging five soft drinks per week.

Pereira’s study found no association between cancer rates and the amount of fruit juice a person drank. Although the study was done in Singapore, Pereira said the results would likely apply to people in the United States because Singapore is a wealthy country with good health care.

But not everyone agrees with the study’s conclusion. Susan Mayne of the Yale Cancer noted that those who drank more soda were also likely to eat red meat and smoke, so the link between soda and pancreatic cancer could be a casual one.

Dr. Emily Winslow, assistant professor of surgery at UW Hospital, agreed that soda intake should be limited but didn’t think it’s the biggest factor in limiting cancer risk.

“The question is: should you reduce your intake of sugar-containing soda products? And I think the answer to that is yes. Overall, most people probably should, particularly if they have a body mass index of higher than 25. And that's for health reasons in general, probably not specifically for having to do with pancreas cancer,” said Winslow.

Instead, Winslow said Americans should be more concerned with other health issues like obesity and smoking, rather than soda intake. She said these two behaviors have stronger links to pancreatic cancer than soda.