When Should You Start Screening for Colorectal Cancer?

If you’re of a “certain age,” you may already know how important regular screenings are in the fight to prevent cancer. Colorectal cancer screenings are especially important if you’re over the age of 45. For those with a high risk of developing this type of cancer, your doctor may want you to start screening even earlier.

Colorectal cancer develops in the colon, rectum, or both. It usually starts in a polyp – a small group of cells that develops on the lining of the colon or rectum. Some polyps are not cancerous, some are pre-cancerous and can turn into cancer, and some are found at an early-stage cancer.  

Colorectal Cancer Screening is the Best Path to Prevention

Finding cancer, or pre-cancerous cells, early and treating it promptly gives you the best chance for a long healthy life. Early treatment is easier on you (and less expensive) compared to late-stage cancer treatment.

The American Cancer Society (ACS) has recently issued an update on when to start colon and rectal cancer screening. Previously, the ACS’ recommended that screening starts at age 50. Based on comprehensive research, they now recommend starting at age 45. Screening sounds a little bit unpleasant, but the benefits are really worth it. Plus, screening for most people can start with a stool sample rather than an outpatient medical procedure. 

Screening for colorectal cancer is important because there aren’t many early warning signs or symptoms. If you have symptoms, it could mean that cancer has already developed or even spread to other organs. Screening must be done regularly to be effective. Always follow your doctor’s recommendations about what tests you need and how often you need them. 

What is Considered High Risk for Developing Colorectal Cancer?

Your doctor will recommend screening methods based on your individual needs and your personal level of risk.  But how do you know your risk category for colorectal cancer?

Average risk means you have a healthy lifestyle and no family history of colorectal cancer. With average risk, you should start screening at age 45 and continue to receive screenings until age 75. Your doctor will discuss whether it's appropriate to continue with screenings after age 75. Most people of average risk are able to start with the at-home stool test given to you by your physician and sent to a lab of their preference. 

High risk means you have certain conditions or factors that may put you at a greater risk of developing cancer. High risk for colorectal cancer can include

• a personal or family history of colon or rectal cancer
• previous radiation of the pelvic region
• a history of inflammatory bowel disease 

High-risk people should start screenings before age 45 and have more frequent screenings than the average-risk group. If you’re over 45 and fall into the high-risk category, but haven’t started screenings, schedule an appointment as soon as you can with your doctor to talk about what tests would be best for you. Just because you’re high risk does not mean you’ve developed cancer. And if you do, the earlier it’s found the better the outcome!  

How to Lower Your Risk for Colorectal Cancer

Some people younger than age 45 may be at a higher risk of developing colorectal cancer. Researchers estimate that colorectal cancer rates will increase by 90% among people in the 20- to 34-year-old age group and by 28% for those between the ages of 35 to 49 over the next ten years. This pattern of increasing rates of colorectal cancer among younger adults is why the ACS lowered its recommended age to start screening to age 45.

The choices you make about how you live your life – lifestyle choices – can determine your chances of getting colorectal cancer. The key lifestyle choices related to cancer include:

• What you eat is important. If you eat a lot of red meat, or processed meats like cold cuts or hot dogs, try substituting fish, chicken, and protein options like cheese, cottage cheese, nuts, and beans. Be sure to include vegetables, fruits, and whole grains (instead of white bread or refined grains). How you cook your food is important, too. Frying, broiling, or grilling meats at high temperatures creates chemical changes in the meat that raises cancer risk. Eating a balanced diet will ensure that your diet has plenty of vitamin D3. Low vitamin D levels can contribute to increased cancer risk.
• How physically active you are is a factor in determining risk. You certainly don’t have to be a super athlete to lower your risk. Just try to do some activity for 30 minutes to an hour, most days of the week. Walking, gardening, dancing, window washing, or hand-washing your car are great ways to get moving.
• Your weight is directly related to colorectal cancer risk, especially for men. Ask your doctor about the best ways to lose weight, or ask for a referral to a dietitian.
• If you smoke, stop or cut back as soon as you can. Tobacco smoke is known to cause cancer. Talk with your doctor about patches, pills, and other quit-smoking methods.
• How much alcohol you drink contributes to a high risk of cancer and at a younger age. Men should limit their daily alcohol to no more than two drinks; women should limit it to one per day. 
• Sugary soft drinks contribute to an unhealthy diet and weight gain. Opt for water, with or without flavorings. Start slowly if you’re not a water drinker, working up to about 100 ounces per day. 

Types of Screening for Colon & Rectal Cancer 

Screening can be done either at home with a stool test or with a visual inspection by a doctor. For most people of average risk, stool tests are the first type of screening recommended. These tests are prescribed by your doctor and done at home. They include:

• Fecal occult blood test (FOBT) looks for hidden blood in the stool, which may indicate polyps, cancer, or other conditions. FOBTs are recommended once a year.
• High sensitivity guaiac-based fecal occult blood test (HSgFOBT) is almost the same as the FOBT. It uses a different chemical to test the stool sample for blood. The ACS recommends it once a year.
• Immunochemical fecal occult blood test (also called fecal immunochemical test, or FIT) checks for antibodies that can indicate blood in the stool. 
• DNA stool test checks the DNA in your stool for genetic changes that can indicate colorectal cancer. The ACS recommends it every three years. 

Visual tests require you to completely empty your colon before the test, allowing the doctor to more accurately see the colorectal lining. It’s important to take all of the prescribed medication to clear the colon so that your doctor can see clearly.

Visual colorectal screening tests include: 

• Sigmoidoscopy lets your doctor look inside your rectum and lower colon for polyps or other abnormal areas. A thin tube with a light and lens for viewing is inserted through the rectum. Your doctor may recommend this every three to five years, depending on the results. It can be done every 5 to 10 years if you also have an annual FOBT or FIT test. A sigmoidoscopy only examines the lower part of your colon. 
• Virtual colonoscopy, also called computed tomographic colonography (CTC), uses specialized x-ray equipment to provide a series of images of the colon and the rectum from outside the body. It is recommended every five years.
• Colonoscopy is considered another screening method that allows the doctor to inspect all six feet of the colon. You’ll be sedated, and a flexible, lighted tube with a viewing lens and a tool for removing polyps is inserted through the rectum. It is usually recommended every ten years if the first one was normal. Any of the above tests that detect an abnormal area must be followed up with a colonoscopy. 

Be Proactive in Your Health and Screen for Colorectal Cancer

At Minnesota Oncology, we stress the importance of early detection. Speak with your doctor about your recommended colorectal screening schedule so that you know your status. Remember, early detection provides your very best options for treatment.