In the United States, colorectal carcinoma (CRC) is the fourth most frequently diagnosed and the second most common cause of cancer-specific death for both men and women (1). The lifetime risk of developing CRC is approximately 6% (2), and treatment costs nearly $6 billion annually (3). As for most epithelial cancers, CRC age-specific incidence increases continuously with biologic aging, with the greatest risk occurring in those individuals aged 80 years or older (2) (Fig. 1 ). Of the more than 148 000 estimated new CRC cases in the year 2002 (4), approximately 40% are expected to die within 5 years (2). Death from CRC is especially unfortunate, given that CRC prevention often can be achieved through screening (5).