High levels of certain protein in blood associated with development of colon cancer


Having elevated concentrations of C-reactive protein (CRP) in the blood is linked to an increased risk for developing colon cancer, according to a study in the February 4 issue of The Journal of the American Medical Association (JAMA).

According to background information in the article, CRP is a protein produced primarily in the liver and is a marker of inflammation. It has been hypothesized that inflammation could play a role in the development of colorectal cancer.

To examine this hypothesis, Thomas P. Erlinger, M.D., M.P.H., of the Johns Hopkins Medical Institutions, Baltimore, and colleagues determined the risk of colon and rectal cancer associated with elevated CRP levels in a prospective study, which included 22,887 adults enrolled between May and October 1989 and followed up through December 2000. A total of 172 colorectal cancer cases were identified through linkage with cancer registries. Up to two controls (n = 342) were selected from the cohort for each case and matched by age, sex, race, and date of blood draw.

The researchers found that plasma CRP concentrations were higher among all colorectal cases combined than controls. "The highest concentration was found in persons who subsequently developed colon cancer vs. matched controls. Among rectal cancer cases, CRP concentrations were not significantly different from controls. The risk of colon cancer was higher in persons in the highest vs. lowest quartile of CRP [2.5 times increased risk]. In nonsmokers, the corresponding association was stronger," the authors write.

"In summary, this study demonstrates that elevated concentrations of CRP are strongly associated with the development of colon cancer in individuals believed to be free of this disease at baseline. This finding is consistent with literature that supports the role of chronic inflammation in the pathogenesis of colon cancer. Additional studies are needed to confirm these findings and to determine the implications on screening and prevention of colon cancer," the researchers conclude.

Source: Eurekalert & others

Last reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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