Cancers of the colon and rectum pose an added threat for men and women with diabetes. Swedish researchers reached this conclusion following an analysis of data from 15 studies, which included >2.5 million participants. Nearly all of the studies had shown an association between diabetes and colon cancer. Some inconsistencies were present, however, including whether the link was seen in both men and women.
Reporting in the Journal of the National Cancer Institute (November 16, 2005), the researchers found that diabetes raised the risk of colorectal cancer by 30%. Further investigation found no major difference between men and women. Diabetes increased the risk of colon and rectal cancers to a similar extent, by 43% and 33%, respectively.