May 22, 2012 -- Should people with diabetes be screened for colon cancer at younger ages than is usually recommended?
That may very well be the case, say researchers who found that people in their 40s with type 2 diabetes are about as likely to have precancerous colon growths called adenomas as people in their 50s without diabetes.
"It's almost as is if having diabetes advances your age by 10 years in this regard," says researcher Susan Hongha Vu, MD, a clinical gastroenterology fellow at Washington University School of Medicine in St. Louis.
If the findings are confirmed in a larger, more robust study, the guidelines should be changed so that people with diabetes start colon cancer screening at age 40, she tells WebMD.
Vu presented the study at the Digestive Disease Week conference in San Diego.
Current guidelines call for men and women at average risk to undergo regular colon cancer screenings beginning at age 50. Colonoscopy, which allows the doctor to view the entire colon and remove any abnormal growths, is the gold standard. There are several other screening options, though, such as flexible sigmoidoscopy and fecal occult blood tests.
But people at high risk of colon cancer should begin screening earlier, according to the recommendations.
Research suggests diabetes may be another such risk factor, Vu says.
"A lot of studies have shown an association between type 2 diabetes and an increased risk of colon cancer," she says.
"Studies also show that diabetes increases the risk of precancerous lesions in the colon," Vu says.
"But as far as we know, no one had taken the next logical step -- that is, to determine whether people with type 2 diabetes should be screened earlier," she says.
Study: Diabetes Appears to Affect Polyp Risk
So the researchers examined the medical records of three groups of people having a colonoscopy over a six-year period at their institution: 125 people ages 40-49 with type 2 diabetes, 125 people 40-49 without diabetes, and 125 people ages 50-59 without diabetes.
Colonoscopy found at least one precancerous polyp in: