Aspirin in the Prevention of Colorectal Cancer

In 1993, there were approximately 152 000 new cases of and 57 000 deaths from colorectal cancer, making this disease one of the most prevalent and lethal malignancies in the United States [1]. A person older than 50 years has about a 5% chance of developing colorectal cancer and a 2.5% chance of dying of the disease. Although slightly more common in men, it is a major health risk for both sexes. Early lesions have an excellent cure rate, but advanced, metastatic disease remains incurable. Thus, the most promising approaches to decreasing the morbidity and mortality from colorectal cancer lie in early detection and prevention.

A recent randomized, controlled trial [2] involving 46 551 participants, showed that screening with fecal occult blood testing can lead to decreases in the number of deaths from colorectal cancer. A 33% cumulative decrease was observed at 13 years in the group having annual screening when compared with the control group. However, a large percentage of the screened group had at least one colonoscopy during the follow-up, thereby raising the possibility that colonoscopy, rather than fecal occult blood screening, was the effective intervention. Sigmoidoscopy and colonoscopy, with removal of precursor adenomas, decrease the incidence of colorectal cancer and its mortality [3, 4]. Nevertheless, widespread use of endoscopy remains impractical and expensive; future advances depend on developing methods for targeted screening in identifiable high-risk persons [5].

Primary prevention of this disease is another promising approach. Fairly consistent epidemiologic data [6, 7] suggest links between diet—those high in fat and low in fiber, certain …