Patients newly diagnosed with coronary artery disease appear to have nearly two times the prevalence of benign and malignant colorectal tumors, according to an article in the September 26 issue of the Journal of the American Medical Association.

Annie On On Chan, MD, PhD, of the University of Hong Kong, China, and colleagues investigated the prevalence of colorectal cancer and colorectal neoplasms in patients with newly diagnosed coronary artery disease. Participants were from Hong Kong and were recruited for screening colonoscopy after undergoing coronary angiography for suspected vascular disease from November 2004 to June 2006.

Presence of coronary artery disease (206 patients) was defined as at least 50 percent diameter narrowing in any one of the major coronary arteries; otherwise, patients were considered disease-negative (208 patients). An age- and sex-matched control group was recruited from the general population (207 patients).

Colorectal neoplasms and advanced lesions were more prevalent (34.0 percent and 18.4 percent, respectively) in the group with coronary artery disease than in the group without it (18.8 percent and 8.7 percent) and the general population (20.8 percent and 5.8 percent).

The prevalence of cancer was 4.4 percent, 0.5 percent, and 1.4 percent, in the groups with vascular disease, without vascular disease, and the general population, respectively. Fifty percent of the cancers in participants with coronary artery disease were early stage.

The researchers also found that both metabolic syndrome and history of smoking were strong independent predictive factors for the positive association between advanced lesions and coronary artery disease.

Regarding the association between these two diseases, the authors speculated: “Both colorectal neoplasm and coronary artery disease probably develop through the mechanism of chronic inflammation. Inflammation is now recognized as being pivotal in the pathogenesis of atherosclerosis and, hence, coronary artery disease. Colorectal cancer is also thought to progress through the pathway of inflammation.”