People With Diabetes May Need Earlier Colon Screen
40-Somethings With Diabetes Have About the Same Risk of Precancerous Growths as 50-Somethings Without Diabetes
Study: Diabetes Appears to Affect Polyp Risk continued...
Still, the study does not prove that diabetes causes or directly contributes to polyp growth.
People with diabetes may have other risk factors for adenomas and colon cancer that weren't measured, says John Petrini, MD, a gastroenterologist at the Sansum Clinic in Santa Barbara, Calif.
Vu says there is a possible explanation for a link between diabetes and colon cancer. People with diabetes have abnormally high levels of insulin in their blood, and insulin can fuel the growth of cells, including precancerous and cancer cells, she says.
The findings are intriguing, Petrini says. But until there is a large, well-designed study confirming the finding, it's too early to talk about changing guidelines, he says.
But should people with diabetes in their 40s go in for early screening if they are concerned? They could, Petrini says. But without guidelines, insurers are unlikely to cover the cost of the test -- about $1,000 in the case of colonoscopy, he says.
On the other hand, a person might opt for a less expensive flexible sigmoidoscopy, which is a good way of identifying people who need a full colonoscopy, Petrini says.
About 25 million Americans have diabetes, and that number is expected to double in the next 25 years. Over 1.1 million have colorectal cancer, according to the American Cancer Society.
These findings were presented at a medical conference. They should be considered preliminary as they have not yet undergone the "peer review" process, in which outside experts scrutinize the data prior to publication in a medical journal.