Prevention of disease with pharmaceuticals

The idea that diseases such as cardiovascular disease and cancer can be prevented by taking a 'pill' is attractive to many people. Chemoprevention is an established method in the primary and secondary prevention of cardiovascular disease such as myocardial infarct and stroke. Clinical trials have demonstrated beyond reasonable doubt that both fatal and non-fatal coronary events and strokes can be prevented. Antihypertensive drugs have been shown to be effective through clinical trials in preventing myocardial infarctions, stroke and other cardiovascular morbidity and mortality. Statins are commonly used to lower the blood cholesterol concentration, and aspirin is widely used to prevent occlusive vascular disease. Aspirin and other non-steroidal antiinflammatory agents have shown promise in the chemoprevention of colorectal cancer. While observational epidemiological studies have consistently suggested that diets rich in antioxidants such as beta-carotene might be useful in preventing coronary heart disease and cancer, the published reports of randomized trials clearly indicate that beta-carotene supplements are of no value in persons of high risk for such conditions. Although the chemoprevention of cancer is decades behind that of cardiovascular disease, there is no reason to believe that progress in cancer chemoprevention will differ substantially from that in cardiovascular disease. Better understanding of the molecular steps critical to carcinogenesis should open new avenues for cancer chemoprevention.