Tuesday, September 25, 2007

Colorectal Tumor Risk Greater For People With Coronary Artery Disease

Colorectal Tumor Risk Greater For People With Coronary Artery Disease

25 Sep 2007

People with coronary artery disease have nearly twice the risk of developing colorectal tumor cancers, compared to people without the disease - the link is even stronger for people with coronary artery disease (CAD) who also smoke(d) or have metabolic syndrome, says a report in the Journal of the American Medical Association (JAMA).

Approximately one in every twenty people worldwide will develop colorectal cancer; it is the second most common cancer. CAD is the foremost cause of death in industrialized countries, write the authors as background to the article. Precancerous tumors or cancer (colorectal neoplasm) or CAD share similar risk factors, therefore their co-occurrence may be linked.

Annie On On Chan, M.D., Ph.D., of the University of Hong Kong, China, and team wanted to see how close the link between colorectal cancer and colorectal neoplasms was in patients who had recently been diagnosed with CAD.

The study participants, all from Hong Kong, were recruited for screening colonoscopy after undergoing coronary angiography for suspected CAD during the period November 2004 to June 2006. They defined CAD as a narrowing of 50% or more in any one of the major coronary arteries - otherwise, the subjects were considered CAD-negative. 206 were CAD-positive, while 208 were CAD negative. A control group of 207, matched for age and sex was recruited from the general population.

Below is what the researchers found:

CAD-Positive Group
-- prevalence of colorectal neoplasms - 34%
-- prevalence of advanced lesions - 18.4%
-- prevalence of cancer - 4.4% (half were early stage)

CAD-Negative Group
-- prevalence of colorectal neoplasms - 18.8%
-- prevalence of advanced lesions - 8.7%
-- prevalence of cancer - 0.5%

Control Group
-- prevalence of colorectal neoplasms - 20.8%
-- prevalence of advanced lesions - 5.8%
-- prevalence of cancer - 1.4%

It was also found that a history of smoking and/or metabolic syndrome were significant independent predictive factors for the positive link between advanced lesions and CAD.

The authors wrote "Both colorectal neoplasm and CAD probably develop through the mechanism of chronic inflammation. Inflammation is now recognized as being pivotal in the pathogenesis of atherosclerosis and, hence, CAD. Colorectal cancer is also thought to progress through the pathway of inflammation." JAMA2007;298(12):1412-1419

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