Colorectal cancer (CRC) develops in the colon or the rectum (known as the large bowel or large intestine). Most colorectal cancer begins as an abnormal growth that develops on the lining of the colon or rectum. These growths can be surgically removed to reduce cancer risk. Colonoscopy plays an important role in colorectal cancer prevention because these growths, called polyps, can be detected and removed during the same exam they are discovered. Beginning at age 50, both men and women at average risk for developing CRC should have a colonoscopy every 10 years.
Why Screen for CRC?
The majority of CRC can be prevented with proper screening, early detection and removal of growths. While a colonoscopy is the screening procedure that most people are aware of, in fact there are other methods for screening as well, such as stool-based (fecal) testing, which looks for signs of blood that may be a warning sign of cancer. (A colonoscopy would still be needed if the test results are abnormal.)
Screening helps prevent CRC by finding precancerous growths so they can be removed before they turn into cancer. The five-year survival rate for people with CRC discovered early is greater than 90 percent. But only 39 percent of CRCs are found at that early stage. Five-year survival rates go down when the cancer has spread to nearby organs or lymph nodes.
Men and women should begin screening earlier and more often if they have any CRC risk factors: a family history of CRC or polyps, a known family history of inherited CRC syndromes, a personal history of CRC, or a personal history of chronic inflammatory bowel disease (ulcerative colitis or Crohn's disease).
Currently, only about 50 percent of adults who should have colonoscopies get them. That means cancers are being missed and people are getting sick who don’t have to. If you’re due for a colonoscopy, you can use the Community Checkup to see which providers and health plans score well in colon cancer screening.