An inflammation marker in the blood that is already known to predict heart disease may also indicate an increased risk of colon cancer, according to a new Johns Hopkins study.
C-reactive protein, or CRP, is produced primarily in the liver. Higher levels of CRP have been linked to higher risks of several, distinct chronic diseases, such as heart disease, stroke, and diabetes. Researshers hypothesized that inflammation could play a role in developing colorectal cancer. They examined the records of more than 22,000 adults who participated in the CLUE II study -- named for the 1989 "Give Us a Clue to Cancer and Heart Disease" campaign. Study volunteers provided a blood sample and completed a brief health questionnaire. The patients were then followed up with additional questionnaires and tracking data.
Researchers compared the health records of volunteers who developed colon or rectal cancer from the time of the initial blood draw through December 2000 to volunteers who did not develop cancer. They found that CRP levels were higher among people who subsequently developed colon cancer than among those who remained free from disease. However, CRP levels were not significantly different between rectal cancer patients and healthy volunteers.
Researchers also found the higher the CRP levels, the higher the odds are of developing colorectal cancers. Specifically, people in the highest quarter of CRP had more than two-times the risk of developing colon cancer than those in the lowest fourth.
The study also shows those who had taken either aspirin or non-steroidal anti-inflammation agents within 48 hours prior to blood draw had a reduced risk of colorectal cancer, and the association of inflammation with colon cancer was unrelated to diabetes, going against the belief that diabetes acts as the mediator between inflammation and cancer risk.
Specialists however say that It's not clear yet how or whether measuring C-reactive protein would fit into current screening and prevention strategies for colorectal cancer but they say further studies are needed to help clarify the mechanism by which inflammation increases the risk of cancer.