Colorectal cancer screening is vital

Colorectal cancer is one of the most common cancers in the United States, with over 135,000 new cases diagnosed annually. Unfortunately, it can be very lethal, and currently over 50,000 Americans die each year of colorectal cancer, which accounts for 8 percent percent of all cancer deaths.

Risk factors for colorectal cancer include older age, family history, inflammatory bowel disease, race, physical inactivity, unhealthy diet (a diet high in fat and red or processed meats, and low in fiber, fruits, and vegetables), smoking, diabetes, excessive consumption of alcohol and obesity. Age is one of the strongest risk factors, with the incidence increasing sharply after the age of 50. Unfortunately, recent data show that the number of cases of colorectal cancer seems to be increasing in younger patients, for unknown reasons.

The good news about colorectal cancer is that it is potentially curable if caught early, and there are several effective screening methods that allow it to be detected early. Colorectal cancer screening recommendations are modified for persons with a family history of the diease, and in patients with inflammatory bowel disease. Colon cancer screening works, because most colorectal cancer develops from precancerous polyps, which are growths in the colon. These polyps may take up to 10 years to become cancerous. If these polyps are detected early and removed, the risk of developing colorectal cancer can be drastically reduced. If the early detection of colorectal cancer is achieved, the chances of dying of are much reduced as well.

There are several types of tests available for screening. They include: colonoscopy, sigmoidoscopy, CT colonography (virtual colonoscopy), stool guaiac (blood) test, and stool DNA testing. In an average risk individual, screening should begin at age 50 in Caucasians and at age 45 in African-Americans. Only 66 percent of adults in Georgia over the age of 50 have had colon cancer screening. The goal set by the American Cancer Society is to reach 80 percent screening by the year 2019.

Colonoscopy is the most effective method of colorectal cancer screening. This allows your physician to see the lining of the rectum and the entire colon. It does require you to do a laxative prep prior to the procedure and then to be sedated during the procedure. Colonoscopy also allows the physician to potentially remove any polyps if discovered during the procedure.

Sigmoidoscopy will allow the physician to view the lining of the rectum and the lower part of the colon, and can be done without sedation and with less laxative prep. The disadvantage is that it only allows the physician to see part of the colon, and not the upper part of the colon.

CT colonography or virtual colonoscopy is an X-ray test performed by a radiologist. It can visualize the colon and determine if polyps or cancers are present. It too requires a laxative prep, but does not require sedation. However if a growth is detected, then the patient will need to be referred for a colonoscopy for biopsy or removal.

There are two types of stool tests available for colorectal cancer screening. The first is guaiac testing, which checks for blood in the stool. Many times polyps or cancers will bleed small amounts that are too small to be noticed by the patient. Guaiac tests may reveal this bleeding, and then the patient can be referred for additional testing, usually a colonoscopy. The guaiac test may be falsely negative, though, if the polyp or cancer is not bleeding, or if it is only bleeding intermittently. The other type of stool testing is a DNA test (“Cologuard”) that looks for specific DNA markers that may indicate that colon cancer is present, and that also looks for blood in the stool. Again, if this test is positive, the patient will need to be referred for a colonoscopy.

The bottom line is to undergo colorectal cancer screening according to your risk. Any type of screening is better than no screening, and, in most experts’ opinions, colonoscopy is the preferred screening method. Certainly any type of rectal bleeding or change in stool characteristics should be evaluated by your physician. Even if you do not meet the age recommendations for screening, do not ignore the symptoms, as they may or may not indicate colorectal cancer or some other type of serious colon disease.

This story was originally published April 14, 2017 at 1:00 PM with the headline "Colorectal cancer screening is vital."