Colon cancer and rectal cancer are often referred to as one because the rectum is part of the colon. It is the second most common cancer in the United States. In 1992, it affected more than 156,000 Americans and caused 58,000 deaths. It is the third leading cause of cancer deaths in the United States. Densely populated, industrialized regions seem to have more cases than rural areas.
Colorectal cancer is rare in less developed areas such as Africa, most of Asia, and Latin America.
However, the rates are very high in North America and northern and western Europe. Rectal cancer occurs in half as many people as colon cancer. The majority of the cases occur in people between the ages of 50 and 75. The average age at the time of diagnosis is 60 years old. People with chronic ulcers, women with a history of breast cancer, and people with a family history of colorectal cancer are at high risk.