About Screening, Early Detection, and Treatment for Colorectal Cancer Q and A About Screening, Early Detection, and Treatment for Colorectal Cancer 1. Colorectal cancer occurs when cells in the colon or rectum become abnormal and divide without control or order. Cancer cells can invade and destroy the tissue around them. They can also break away from the tumor and spread to form new tumors in other parts of the body. The exact causes of colorectal cancer are not known.
Colorectal cancer is more likely to occur as people get older.
Most people who develop colorectal cancer are over the age of 50. However, the disease can occur at any age. The development of colorectal cancer seems to be associated with a diet that is high in fat and calories and low in foods with fiber, such as whole grains, fruits, and vegetables. Researchers are exploring how these and other dietary components play a role in the development of colorectal cancer. They are relatively common in people over age 50.