NEW YORK (Reuters Life!) - People with diabetes are at higher risk for certain cancers than those without the blood sugar disease, including colon and pancreatic cancer for men and breast cancer for women, according to a U.S. study.
Based on a telephone survey of nearly 400,000 adults, the study -- whose findings appear in "Diabetes Care" -- found that 16 out of every 100 diabetic men and 17 out of every 100 diabetic women said they had cancer.
That compares to 7 per 100 men and 10 per 100 women without diabetes.
"The significant association between cancer and diabetes does not surprise us," said Chaoyang Li, an epidemiologist at the Centers for Disease Control and Prevention in Atlanta, George, the lead author.
Li told Reuters Health that other studies have also found a link between diabetes and cancer, although there is no proof that one causes the other.
According to the CDC, nine percent of U.S. adults have diabetes.
After taking into account things such as age, race, smoking and drinking habits, the researchers concluded that diabetic men and women were 10 percent more likely to have had a cancer diagnosis of any kind.
Compared to people without diabetes, diabetic men were more likely to report having colon, pancreas, rectum, urinary bladder, kidney or prostate cancer. Diabetic women had more cases of breast cancer, leukemia or a type of uterine cancer.
For men, the greatest increase in risk was for pancreatic cancer, with 16 per 10,000 cases among diabetics and just two per 10,000 among non-diabetics. -- a four-fold difference after other factors are taken into consideration.
Women's risk of leukemia also rose sharply. One per 1,000 women without diabetes said they had been diagnosed with the blood cancer, compared to three per 1,000 women with diabetes.
The study is just a snapshot of peoples' medical history and does not follow them over time.
"It shows there's a substantial pool of American adults who have diabetes and cancer," said Fred Brancati, a professor at Johns Hopkins University in Baltimore.
"The authors rightly point out that these two conditions go together beyond chance alone, so it pays to think about them together."
Brancati's own research has shown that the risk of death from cancer among diabetics is about 40 percent higher than among non-diabetics.
Li said it's still unclear why diabetes is tied to cancer. High blood sugar levels or excess blood insulin -- a hormone that helps ferry sugar into the cells -- might increase the risk, but that has not been proven.
Reporting by Kerry Grens at Reuters Health; editing by Elaine Lies