Excluding skin cancers, colorectal cancer is the third most common cancer diagnosed in men and women in the United States. The American Cancer Society estimates that about 98,200 new cases of colon cancer (46,200 men and 52,000 women) and 37,200 new cases of rectal cancer (21,100 men and 16,100 women) will be diagnosed in 2001.

Colon cancer is expected to be responsible for about 48,100 deaths (23,000 men and 25,100 women) during 2001. About 8,600 people (4,700 men and 3,900 women) will die from rectal cancer during 2001.

The death rate from colorectal cancer has been going down for the past 20 years. This may be because there are fewer cases, they are found earlier, and treatments have improved.

The 5-year relative survival rate is 90% for people whose colorectal cancer is found and treated in an early stage, before it has spread. But, only 37% of colorectal cancers are found at that early stage. Once the cancer has spread to nearby organs or lymph nodes, the 5-year relative survival rate goes down to 65%. For people whose colorectal cancer has spread to distant parts of the body such as the liver or lungs, the 5-year relative survival rate is 8%.

The 5-year survival rate refers to the percent of patients who live at least 5 years after their cancer is diagnosed. Many of these patients live much longer than 5 years after diagnosis, and 5-year rates are used to produce a standard way of discussing prognosis. Five-year relative survival rates exclude from the calculations patients dying of other diseases, and are considered to be a more accurate way to describe the prognosis for patients with a particular type and stage of cancer. Of course, 5-year rates are based on patients diagnosed and initially treated more than 5 years ago. Improvements in treatment often result in a more favorable outlook for recently diagnosed patients.