Colon Cancer Screening

Colorectal cancer is cancer that occurs in the colon or rectum. The rectum is the passageway that connects the colon to the anus.

Sometimes abnormal growths, called polyps, form in the colon or rectum. Over time, some polyps may turn into cancer. Screening tests, such as a colonsocopy, can find polyps so they can be removed before turning into cancer. Screening also helps find colorectal cancer at an early stage, when treatment often leads to a cure.

Your risk of getting colorectal cancer increases as you get older. More than 90% of cases occur in people who are 50 years old or older. There are other risk factors for colon cancer, including:

Inflammatory bowel disease, Crohn’s disease, or ulcerative colitis.
A personal or family history of colorectal cancer or colorectal polyps.
A genetic syndrome such as familial adenomatous polyposis (FAP) or hereditary non-polyposis colorectal cancer (Lynch syndrome).

Lifestyle factors that may contribute to an increased risk of colorectal cancer include:

Lack of regular physical activity.
Low fruit and vegetable intake.
A low-fiber and high-fat diet.
Overweight and obesity.
Alcohol consumption.
Tobacco use.

What Can I Do to Reduce My Risk of Colorectal Cancer?

Almost all colorectal cancers begin as precancerous polyps (abnormal growths) in the colon or rectum. Such polyps can be present in the colon for many years before invasive cancer develops. They may not cause any symptoms. Colorectal cancer screening with colonoscopy is the best way to find precancerous polyps, so they can be removed before they turn into cancer. In this way, colorectal cancer is prevented. Screening with a colonoscopy can also find colorectal cancer early, when there is a greater chance that treatment will be most effective and lead to a cure. A screening colonoscopy at the age of 50 is recommended to check for and remove polyps. If you have a family history of colon cancer or colon polyps, you may need to have a screening colonoscopy at a younger age.

Research is underway to find out if changes to your diet can reduce your colorectal cancer risk. Medical experts don’t agree on the role of diet in preventing colorectal cancer, but often recommend a diet low in animal fats and high in fruits, vegetables, and whole grains to reduce the risk of other chronic diseases, such as coronary artery disease and diabetes. This diet also may reduce the risk of colorectal cancer. Also, researchers are examining the role of certain medicines and supplements, including aspirin, calcium, vitamin D, and selenium in preventing colorectal cancer.

Some studies suggest that people may reduce their risk of developing colorectal cancer by increasing physical activity, limiting alcohol consumption, and avoiding tobacco.

Overall, the most effective way to reduce your risk of colorectal cancer is by having regular colorectal cancer screening beginning at age 50. A colonoscopy is the most complete and accurate test available to diagnose polyps and remove them.

What Are the Symptoms of Colorectal Cancer?

Colorectal polyps and colorectal cancer don't always cause symptoms, especially at first. Someone could have polyps or colorectal cancer and not know it. That is why getting screened regularly for colorectal cancer is so important.

If you have symptoms, they may include:

Blood in or on your stool (bowel movement).
Stomach pain, aches, or cramps that don’t go away.
Losing weight and you don’t know why.

If you have any of these symptoms, talk to your doctor. They may be caused by something other than cancer. The only way to know what is causing these symptoms is to see your doctor.