Colorectal cancer is a disease in which malignant (cancer) cells form in the tissues of the colon or the rectum.
The colon is part of the body's digestive system. The digestive system removes and
processes nutrients (vitamins, minerals, carbohydrates, fats, proteins, and
water) from foods and helps pass waste material out of the body. The digestive
system is made up of the mouth, throat, esophagus,
stomach, and the
small and large intestines. The first 6 feet of the
large intestine are called the large bowel or colon. The last 6 inches are the
rectum and the anal canal. The anal canal ends at the
anus (the opening of the large intestine to
the outside of the body).
Cancer that begins in the colon is called colon cancer, and cancer that begins in the rectum is called rectal cancer. Cancer that affects either of these organs may also be called colorectal cancer.
See the following PDQ summaries for more information about colorectal cancer:
Colorectal cancer is the second leading cause of death from cancer in the United States.
The number of new colorectal cancer cases and the number of deaths from colorectal cancer are both decreasing a little bit each year. However, in adults younger than 50 years, the number of new colorectal cancer cases has slowly increased since 1998.
Finding and treating colorectal cancer early may prevent death from colorectal cancer. Screening tests may be used to help find colorectal cancer.