Colorectal cancer is a disease in which malignant (cancerous) cells appear in the tissues of the colon or rectum.
The colon is part of the body’s digestive system. The digestive system absorbs and processes nutrients from food (including vitamins, minerals, carbohydrates, fats, proteins, and water) and excretes metabolic wastes from the body. The digestive system includes the mouth, pharynx, esophagus, stomach, small intestine and large intestine. The colon (large intestine) is about 1.5 meters long and is the first part of the large intestine. The last part of the large intestine consists of the rectum and the anal canal, which is about 15-20 cm long. The anal canal ends in the anus (the opening at the end of the large intestine to the outside of the body).
Anatomy of the lower digestive system; shows the colon and other organs.
Cancer that begins in the colon is called colon cancer, and cancer that begins in the rectum is called rectal cancer. Those that involve either of these organs may also be called colorectal cancer.
For more information about colorectal cancer, see the following PDQ overview:
Colorectal cancer is the third leading cause of cancer death in the United States.
In adults ≥55 years of age, the number of new cases and deaths from colorectal cancer has declined slightly each year. However, among adults younger than 55 years, the number of new colorectal cancer cases has been slowly increasing in recent years. The number of new cases and deaths from colorectal cancer is higher among African Americans than among other racial groups.
Early detection and treatment of colorectal cancer can reduce colorectal cancer mortality. Colorectal cancer can be detected through screening tests.