One of the most powerful weapons in preventing colorectal cancer is regular colorectal cancer screening or testing. Regular colorectal cancer screening can, in many cases, prevent colorectal cancer altogether. This is because most colorectal cancers start as polyps, which are non-cancerous growths in the lining of the colon or rectum. From the time the first abnormal cells start to grow, it usually takes years for them to develop into colorectal cancer. Testing often finds these polyps, and allows them to be removed before they have the chance to turn into cancer. Screening can also result in finding colorectal cancer early, when it may be curable.
Most people with early colon cancer don’t have symptoms. Symptoms usually appear with more advanced disease.
Most of these symptoms are more likely to be caused by something other than colorectal cancer. Still, if you have any of these problems, it's important to see your doctor right away so the cause can be found and treated, if needed. Detecting colorectal cancer early may save your life.
There are several tests used to screen for colorectal cancer in those with an average risk of colorectal cancer. Ask your doctor which tests are available and which option is best for you. People who have no identified risk factors (other than age) should begin regular screening at age 50. Those who have a family history or other risk factors for colorectal polyps or cancer should talk with their doctor about starting screening at a younger age and/or getting screened at more frequent intervals.
According to the American Society of Colon and Rectal Surgeons (ASCRS), all men and women aged 50 and older should be screened for colorectal cancer. There are five different colorectal cancer-screening procedures available, but the frequency of screening varies depending upon a person's medical history. Patients should talk to their colorectal surgeon or other healthcare provider about which procedures are right for them and how often they should be screened.
Fecal Occult Blood Test (FOBT)
An FOBT is a simple chemical test that can detect hidden blood in the stool, which may be a symptom of colorectal cancer. Patients can perform this test in the privacy of their own home by using a small stick from a test kit to apply to a test card a thin layer of stool from three consecutive bowel movements. After the samples have been collected, the patient sends the test card to the physician's office where it is checked for hidden blood. If blood is found, the colorectal surgeon may recommend a follow up colonoscopy.
Recommended testing: Beginning at age 40, all adults should have an FOBT once every year.
Flexible Sigmoidoscopy
A flexible sigmoidoscopy is a visual examination of the rectum and lower portion of the colon, where most colorectal polyps and cancers occur. To perform the test, a physician inserts a thin flexible tube with a tiny camera on the end into the rectum and up into the colon to look for abnormalities or polyps. Although tissue samples and polyps can be removed with the endoscope, a follow-up colonoscopy generally is necessary if polyps or other abnormalities are found. Flexible sigmoidoscopy exams usually are performed in a hospital or doctor's office.
Recommended testing: Beginning at age 50, a flexible sigmoidoscopy should be conducted every 5 years.
Double-contrast Barium Enema (DCBE) or Barium X-ray
The DCBE is an x-ray examination of the rectum and entire colon performed in a hospital or clinic. With this procedure, the colorectal surgeon gives the patient an enema containing white dye or barium followed by an injection of air. The barium outlines the intestine and enables the surgeon to take x-rays of the lower intestine.
Recommended testing: Beginning at age 50, all adults should have a DCBE once every 5-10 years.
Colonoscopy
A colonoscopy is a visual examination of the rectum and entire colon, performed by a colorectal surgeon in a hospital or clinic. This exam is similar to the flexible sigmoidoscopy, except that the thin tube is inserted into the rectum and through the entire length of the colon. If polyps are found, they can be removed during this procedure. Because this exam is more invasive than the flexible sigmoidoscopy, sedation is given the patient before performing the procedure. The bowel must be completely empty for this visual examination, so patients must adhere to a colon-cleansing prep.
Recommended testing: A screening colonoscopy is performed once every 10 years on adults 50 years and older.
Digital Rectal Examination
This is an examination where the colorectal surgeon inserts a finger (digit) covered with a lubricated glove into the rectum to feel for abnormalities. It is a simple test that is not painful and can detect many rectal cancers.
Recommended testing: Beginning at age 50, all adults should have a digital rectal exam once every year.