my personal edition > colorectal cancer > news


  E-Mail this DGDispatch to a colleague

DGDispatch

Diabetics Face Increased Risk of Colorectal Cancer: Presented at ACG

By Paula Moyer

HONOLULU, HI -- November 2, 2005 -- Colorectal cancer occurs significantly more frequently in people with diabetes than in healthy people, according to investigators who presented their findings here at the 70^th annual meeting of the American College of Gastroenterology (ACG).

"Because we had seen an indication in smaller studies that people with diabetes faced a higher risk [of colorectal cancer], we wanted to see whether this was true," said principal investigator Donald Garrow, MD, MS, Clinical Instructor of General Internal Medicine, Medical University of South Carolina, Charleston, South Carolina, United States.

"We used 7 years' worth of data from a large national database, and our findings confirmed this concern," Dr. Garrow said during his presentation on November 1^st.

A further rationale for the study was based on several in vitro studies, which had shown that hyperinsulinemia and hyperglycemia promote the growth of colorectal cancer, and that both insulin and insulin-like growth factor-1 (IGF-1) receptors are found in these tumors. And high levels of circulating IGF-1 have been linked to both certain benign polyps and to cancer, he added.

The investigators obtained the responses to the National Health Interview Survey (NHIS) of 226,953 subjects who participated during 1997 to 2003. Among these subjects, 5.9% (n = 13,399) reported a history of diabetes.

The analysis controlled for factors that are associated with both diabetes and colorectal cancer, including obesity, race, and smoking status, as well as age and gender.

Subjects with diabetes were 1.4 times more likely to develop colorectal cancer than non-diabetics. The rate of colorectal cancer among those with diabetes was 1.39% and 0.47% among those without diabetes (P < .001). The odds ratio (OR) for colorectal cancer in diabetics was 1.39 (confidence interval [CI] = 1.15-1.67).

The OR for people who were older than 50 years was 13.9 (CI = 10.66-18.14), a predictable finding, Dr.Garrow said. However, the OR for white respondents was 1.29 (CI = 1.29-1.58). Obese respondents had an OR of 0.79 (CI = 0.66-0.93), while former smokers and users of alcohol had increased risks, with ORs of 1.43 (CI=1.22-1.69) and 1.10 (CI=0.90-1.34), respectively.

Current guidelines recommend that colorectal cancer screening start at the age of 50 years old in diabetics. However, Dr. Garrow said that if future studies corroborate the findings from this study, it may be necessary to recommend that diabetics receive more aggressive screening.


[Presentation title: Individuals with Diabetes Have an Increased Risk of Colorectal Cancer. Abstract 887]

E-Mail this DGDispatch to a colleague

To print, use this version