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.
Editor's Note: This study was supported by a grants from the Maryland Cigarette Restitution Fund, the National Institutes of Health, and the American Institute for Cancer Research.
EDITORIAL: IS C-REACTIVE PROTEIN AN INFLAMMATION MARKER THAT SIGNALS COLON CANCER RISK?
In an accompanying editorial, Boris Pasche, M.D., Ph.D., of the Northwestern University Feinberg School of Medicine, and Contributing Editor, JAMA, Chicago, and Charles N. Serhan, Ph.D., of Brigham and Women's Hospital and Harvard Medical School, Boston, point out that the future of CRP as a marker of colon cancer risk remains to be further defined.
"The provocative findings of Erlinger et al are likely to stimulate basic scientists and epidemiologists alike to further explore the relationship between inflammation and colon cancer. More than 70 years after being discovered in patients with pneumonia, CRP is now linked with one of the most common forms of cancer.
(JAMA. 2004;291:623-624. Available post-embargo at JAMA.com.)
Editor's Note: This work is supported in part by grants from the National Institutes of Health. Dr. Pasche is the recipient of a Career Development Award from the Avon Foundation.
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