Colon cancer: what you need to know

Which health trend is grabbing your attention? Gluten-free diets, weight training, Zumba, protein supplements -- the list is endless of fad diets and exercise regimens for improving your health. What about other preventative services? Now is a great time to think about preventative screenings.

One very valuable tool is a colon cancer -- or colorectal cancer -- screening, which can catch pre-cancerous changes in the colon. Colorectal cancer is the second-leading cause of death from cancer, according to the U.S. Centers for Disease Control and Prevention (CDC), though the rates are declining as screening methods are increasingly more common. One third of patients diagnosed with colorectal cancer will lose their life due to the disease.

What is colorectal cancer?

Colorectal cancer is a disease in which cells in the colon or rectum grow out of control. Sometimes it is called colon cancer, for short. The colon is the large intestine or large bowel. 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.

Who should be screened?

Routine screening begins at age 45 for both men and women. If someone has an increased risk, the screening could start earlier. For example, if a parent or sibling has a history of colorectal cancer, the recommended screening should start at age 40 or 10 years before the age of onset for the family member, whichever comes first. Risk factors include: family history of colorectal cancer, Crohn's disease, ulcerative colitis, previously found colon polyps, increased age (more than 50 years), tobacco use, high-fat diet, low physical activity, lifestyle, alcohol use, and obesity.

How is screening done?

There are several screening methods, including colonoscopy, flexible sigmoidoscopy, CT colonography, stool DNA test, and blood stool test. However, colonoscopy is the most sensitive screening method.

• Colonoscopy: A thin tube is inserted in the colon, allowing the clinician to visualize the tissue of the entire colon, identify any precancerous changes, and take a biopsy if any suspicious tissue or polyps are present. If polyps are present, they might be removed. This screening is repeated every 10 years unless a polyp is identified, then it's done in 3-5-year intervals.
• Flexible sigmoidoscopy: Similar to the colonoscopy, a thin tube is inserted into the last portion of the large colon (sigmoid colon) that allows the clinician to visualize the rectal and last portion of the colon, identify any concerning changes, and take a biopsy if needed. This test, however, does not allow for screening of the entire colon. It is repeated every 5 years, and a stool test is performed as well every year.
• CT colonography: Also called a virtual colonoscopy, this test uses X-rays and computers to produce images of the entire colon, which are displayed on a computer screen for the doctor to analyze. It is repeated every 5 years.
  
• Stool DNA test: A stool sample is sent to a laboratory for evaluation to screen for abnormal DNA markers that might indicate cancerous changes. Cologuard is one example. These tests are repeated every 3 years.
• Stool blood test: Cancer might result in microscopic blood passing in the stool that could be identified by the collection of a stool sample. Although this test might indicate colon irritation related to cancer, it also could be the result of blood thinners, NSAIDs (ibuprofen), hemorrhoids, or other conditions. This test is repeated every year.

If you are over the age of 50 or have any of the risk factors, please talk with your healthcare provider about your risk and screening options. Encourage friends and family to take action in preventing colon cancer. These measures could save your life. If you have any questions, feel free to contact our office or visit the CDC website for more information (cdc.gov/cancer/colorectal/basic_info/what-is-colorectal-cancer.htm).

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