March is National Colorectal Cancer Awareness Month. Colon cancer refers to cancer of the large intestine and rectum.
According to data from the National Center for Health Statistics, each year in the United States 140,000 people are diagnosed with colon cancer and 50,000 die from the disease.
This makes colon cancer the second-leading cause of cancer death among both men and women in the United States. Nearly 1 in 20 Americans will be diagnosed with colon cancer.
More importantly, colon cancer is preventable and curable through screening and early detection. Risk factors for colon cancer include: family history of the disease, tobacco use, obesity and certain health conditions such as inflammatory bowel disease.
In many instances, colon cancer arises from the growth of precancerous polyps along the inner mucous membrane lining of the colon.
These polyps often grow slowly over a period of years and over time may undergo cancerous transformation.
At no point, from the initial formation of the polyp to early cancerous transformation, are symptoms common. In fact, symptoms of colon cancer typically do not occur until its later stages, when treatment options are more limited. For this reason, screening is important.
Screening for colon cancer is generally recommended beginning at age 50. Screening may need to start earlier for persons with high-risk conditions or a family history.
For instance, if you have a first-degree relative such as a parent or sibling with colon cancer, you should start being screened at age 40, or 10 years before the age of your relative’s diagnosis, whichever comes first.
The U.S. Preventive Services Task Force recommends screening by a number of methods, including stool testing yearly, sigmoidoscopy every 5-10 years or a colonoscopy every 10 years.
Sigmoidoscopy involves insertion of a camera on a scope into the rectum and partially into the colon, whereas colonoscopy involves advancing the scope into the entire colon. These procedures require a prior-colon cleanse regimen. Usually, the procedure is performed under anaesthesia.
Stool testing involves the patient collecting samples of stool at home which are submitted to the lab to test for signs of cancer.
Colonoscopy not only permits detection of polyps or early cancer, it permits the removal of precancerous polyps, thus preventing cancer from occurring in the first place.
A recent study demonstrated the advantages of full colonoscopy as a screening method. Researchers determined that when the procedure resulted in removal of precancerous polyps, the risk of colon cancer-related death was cut by more than one-half. Partly for this reason, colonoscopy is the preferred colon cancer screening method according to many experts.
If you are age 50 or older or if you believe you may be at high risk for colorectal cancer, talk to your health-care provider, who can help you decide what screening strategy is best for you.
Dr. Matthew A. Clark is a board-certified physician in internal medicine and pediatrics practicing at the Ute Mountain Health Center in Towaoc.