ABSTRACT
Worldwide, colorectal cancers (CRC) occur in approximately 8.1 million people and cause 5.2 million deaths each year. Nearly 150 000 new cases of colon and rectal cancer are diagnosed each year in the US, and it is the second leading cause of cancer death in this country 1 . These include approximately 106 000 colon cancers with the remainder being rectal cancers. Of sporadic CRC 90% occur in people after their fifth decade and it is uncommon before the age of 40. There has been an overall decrease in the incidence rates over the past 20 years which is attributed to increased screening and prevention with the more widespread use of colonoscopy. During this time, however, the incidence of right-sided colon cancers has been increasing in the US and Europe. The overall incidence is higher in patients who have an inherited predisposition to CRC. This occurs in fewer than 10% of patients with CRC and these cases are subdivided according to whether or not colonic polyps are a major disease manifestation.
