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Does Coronary Artery Disease Increase Risk for Colorectal Neoplasia?

Some studies support an association, but many questions remain.

Some studies suggest that coronary artery disease (CAD) is a risk factor for colorectal neoplasia, but the association has never been established fully. To explore this possible link further, investigators conducted a cross-sectional study among 621 patients at three Hong Kong hospitals: 206 patients who had undergone coronary angiography and had 50% diameter stenosis in at least one of the major coronary arteries (the CAD-positive group); 208 patients who had undergone coronary angiography but did not have CAD (the CAD-negative group); and 207 patients who were seen for epigastric pain, had not undergone coronary angiography, and were matched with CAD-positive patients for age and sex (the "general population").

All three groups underwent screening colonoscopy. The prevalence of colorectal neoplasia was 34.0% in the CAD-positive group, 18.8% in the CAD-negative group, and 20.8% in the general population. Advanced lesions were found in 18.4%, 8.7%, and 5.8% of the groups, respectively. The prevalence of cancer was 4.4%, 0.5%, and 1.4%, respectively. History of smoking and presence of metabolic syndrome were independent predictors of colorectal neoplasia. After adjustment for age and sex, CAD was associated significantly with colorectal neoplasia (odds ratio, 1.88; 95% CI, 1.25–2.70) and with advanced lesions (OR, 2.51; 95% CI, 1.43–4.35).

Comment: A growing body of evidence indicates that cigarette use, diabetes, and metabolic syndrome are each associated with an increased risk for colorectal adenomas and cancer and that patients with these risk factors might require earlier or more-frequent screening. However, I would prefer to see the results of the present study corroborated before I reach any conclusions about CAD as a possible independent risk factor. The most important limitation of this report is the lack of detail about whether the patients with CAD were indeed asymptomatic for colorectal disease, given that symptoms are a risk factor for advanced neoplasia. Although the authors did not clarify which pathologic criteria they used to define colorectal cancer, a prevalence of 4.4% in an asymptomatic population is virtually unheard of. Clearly, additional study is required if we are to understand any possible association between CAD and colorectal neoplasia.

— Douglas K. Rex, MD

Published in Journal Watch Gastroenterology October 26, 2007

Citation(s):

Chan AOO et al. Prevalence of colorectal neoplasm among patients with newly diagnosed coronary artery disease. JAMA 2007 Sep 26; 298:1412.

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