Circulating C-reactive protein (CRP), a marker of low-grade systemic inflammation, is associated with an increased risk of colon cancer, according to data presented at the American Association for Cancer Research 101st Annual Meeting 2010.
"Elevated CRP levels may be considered as a risk marker, but not necessarily a cause, for the carcinogenic process of colon cancer," said Dr. Gong Yang, research associate professor at Vanderbilt University, Nashville, Tenn.
CRP is a protein found in the blood; levels rise in response to inflammation throughout the body. Yang and colleagues at the Vanderbilt-Ingram Cancer Center evaluated the link between CRP levels and colon cancer risk, and the potential effect of time on CRP measures.
Using the Shanghai Women's Health Study, the researchers conducted a case-control study of 338 cases of colorectal cancer and 451 individually matched controls with up to 10 years of follow-up.
CRP levels were positively associated with colon cancer risk in an analysis of 209 cases of colon cancer and 279 controls, according to Yang. Women in the highest quartile of CRP had a 2.5-fold increased risk of colon cancer compared to those in the lowest quartile. This risk was, however, much greater for women with higher levels of CRP measured in blood samples collected close in time to disease diagnosis.
"The positive association between circulating CRP and colon cancer observed in this and some previous studies may be partly explained by cancer-induced inflammation," Yang said.