A prospective cross-sectional study has shown an association between colorectal cancer and coronary artery disease (CAD), with elevated rates of both diseases in patients who are smokers and have the metabolic syndrome.
Colorectal cancer and CAD share some risk factors. This cross-sectional study from Hong Kong investigated patients having coronary angiography for suspected CAD who were invited to have a screening colonoscopy. Hong Kong has a similar incidence and mortality from colorectal cancer and CAD as in Western countries.
CAD, defined as at least 50% stenosis in any of the major coronary arteries, was found in 206 patients and 208 were found to be negative. Age- and sex-matched controls for those with CAD were obtained from the general population, as adequate matching within the CAD-negative group was not possible. Patients were excluded if they had more than one year use of aspirin or statins, a personal history of colonic disease, or had a colonoscopy in the previous 10 years.
Colorectal cancer was found in 34% of patients with CAD, 19% of those without CAD, and 21% of the general population group (p < 0.001). The incidence of advanced colorectal lesions was 18%, 9%, and 6% (p < 0.001) respectively. The researchers said the high rate of advanced lesions in CAD patients was “remarkable”.
The mean age and family history of colorectal cancer was similar in all groups. As expected, CAD patients were more likely to be male, to have the metabolic syndrome, to have higher waist circumference, fasting glucose, triglycerides, and blood pressure, to have low HDL cholesterol and to smoke.
After adjusting for age and sex, there was a significant association between the presence of CAD and both colorectal cancer (odds ratio, 1.88) and advanced colorectal lesions (OR, 2.51). The metabolic syndrome and a history of smoking were independent risk factors for an association between advanced colonic lesions and CAD.
Reference
Chan, A. Jim, M. et al, 2007, ‘Prevalence of colorectal neoplasm among patients with newly diagnosed coronary artery disease.’ Journal of the American Medical Association, vol. 298, pp. 1412-1419.
Abstract