The Latest Colorectal Cancer Screening Guidelines

With colon cancer incidence rates in the United State increasing, as well as cancer diagnoses occurring at a younger age, the need for earlier screening is clear. To help meet this ongoing need, the American Cancer Society’s new colorectal screening guidelines lowered the recommended age for testing from 50 to 45.

As a way to promote awareness for colorectal cancer in March, we’ve covered some of the recent changes in preventive screening, outlined what you need to know if you fall in an at-risk category for colorectal cancer and touched on the importance of scheduling a colonoscopy. 

When should you start colon cancer screenings?

Previous ACS guidelines recommended people at average risk for colon cancer — meaning you have no known risk factors — should receive a colon cancer screening at age 50. That number recently dipped to 45 (with follow-up screenings recommended every 10 years) due to colorectal cancer rates in adults younger than 50 more than doubling since the 1990s.

Once you start screening at age 45, you should continue to receive regular screenings every 10 years until the age of 75. 

Talk to your healthcare provider about screenings if you’re between 76 and 85, as individual situations and personal preferences will differ. Currently, the American Cancer Society doesn’t recommend screening after the age of 85.

Colon cancer screening and family history

Inherited disorders such as familial adenomatous polyposis syndrome, juvenile polyposis and Lynch syndrome, as well as inflammatory bowel disease, put patients at an increased risk of colon cancer at a younger age. But inherited factors only cause 10 to 20 percent of early-onset colorectal cancers, suggesting environmental factors, such as poor diet, inactivity and a rise in smoking in younger adults, are to blame.

In certain cases, colon cancer screenings should start before the age of 45. This mainly applies to those with a family history of colon cancer, genetic syndromes or a medical history that includes certain types of bowel diseases.

Knowing your family history is important as some cancers tend to carry an increased risk within families. This can be from known, or even unknown, genetic disorders. For example, the American Cancer Society suggests early screening for people with a family history of familial adenomatous polyposis (FAP) or Lynch syndrome, two hereditary syndromes that increase your risk of colon cancer. 

If you fall into this category, how early you should begin receiving colon cancer screenings depends on your risk factors. Screening may be required as early the teenage years if genetic syndromes are present. As for family history, having a first-degree relative who developed colon cancer at a young age (less than 45) means you should be screened 10 years before their age at diagnosis, according to the U.S. Multi-Society Task Force of Colorectal Cancer (MSTF). In other words, you should be screened at 30 if your mother, father, brother or sister received a colon cancer diagnosis at 40.

Patients with inflammatory bowel disease, such as ulcerative colitis or Crohn’s disease, are at an increased risk of colon cancer and should undergo routine screening. You will also need more frequent screening if you’ve had abnormal growths called polyps or if you’ve had cancer that required radiation in your abdomen or pelvic area as radiation exposure can lead to the development of other forms of cancer.

The following outlines how often people with certain risk factors should be screened:

• People with genetic syndromes — As early as your teenage years
• People with a previous colon or rectal cancer diagnosis — Every year
• People who have had polyps removed during a previous colonoscopy — Every three years
• People who have been treated with radiation in the abdomen or pelvic area — Five years after radiation or at age 30
• People with inflammatory bowel disease — No later than eight years after diagnosis with follow-ups every one to three years

What is a colonoscopy screening?

Colon cancer affects the large intestine, a 5-foot-long organ at the end of your digestive tract that absorbs water to change liquid waste into solid stool. 

The large intestine is so big in size that it’s made up of four sections. The ascending colon runs vertically and travels up the right side of your midsection where it turns into the transverse colon. This section runs horizontally across your midsection to the left side of your body. There, it turns into the descending colon and travels vertically down to an s-shaped part of the large intestine called the sigmoid colon. 

Because of the large intestine’s length and complexity, a colonoscopy screening is the preferred and most accurate method to test for colorectal cancer. A colonoscopy involves a colonoscope, a long, flexible tube with a light and camera, that allows your doctor to see inside your large intestine. The main purpose of the procedure is to screen for cancer, but it can also be used to check for the following problems:

• Bulging pouches (diverticula)
• Cancerous tumors
• Inflammation
• Narrowing of the color (strictures) 
• Polyps (a clump of cells)
• Ulcers that cause ulcerative colitis

During a colonoscopy, your provider may remove tissue or polyps for further testing. They also have the ability to treat any problems found during the procedure. 

Should you decide on a colonoscopy, don't fear your screening. Any inconvenience involved in the preparation required for a colonoscopy will pay off by increasing your chances of a future clean bill of health. This first-person account of a colonoscopy provides details on what you can expect.

Is there an alternative to a colonoscopy?

Yes. CT colonography and flexible sigmoidoscopy are additional visual exams available for preventive screening, although a colonoscopy is still the preferred method.

Other than visual exams, there are three types of stool studies that act as noninvasive colon cancer screenings: a guaiac-based fecal occult blood test (gFOBT);  fecal immunochemical test (FIT); and a multi-targeted stool DNA test (MT-sDNA). 

However, the noninvasive methods of screening aren’t as accurate as a colonoscopy. They test your stool for blood or DNA to evaluate for the possibility of cancer, but they don’t provide a tissue biopsy which your doctor needs to confirm a cancer diagnosis. If the noninvasive tests return positive, you will still need a colonoscopy to confirm results. Therefore, it makes sense to get a colonoscopy up front if you’re able. 

The importance of colon health and regular screenings

Colon cancer is unique from other types of cancer in that you can generally prevent it and stay ahead of the curve with recommended screenings. Colon cancer is preventable because benign polyps are easy to spot and remove before they turn cancerous.

Colon cancer has a 91 percent five-year localized survival rate, and rectal cancer has an 89 percent five-year survival rate, according to the American Cancer Society. Localized survival rate simply means a cancer diagnosis that hasn’t spread outside the colon or rectum.

You can do your own part to lower your risk of colorectal cancer by modifying a few lifestyle changes. As with most cancers, obesity, lack of physical activity, poor diet and smoking are common risk factors.

Start by maintaining a healthy weight and incorporate moderate to intense physical activity to help lower your risk of cancer. Strive for a daily intake of fruits, vegetables and whole grains high in fiber. A study by the American Cancer Society found low dietary fiber accounted for 10 percent of colorectal cancer cases.

Contact an INTEGRIS Health gastroenterologist if you have questions about your colorectal health or need to inquire about colon cancer screening. If you currently or previously had colorectal cancer and want more information about a specific procedure, contact the INTEGRIS Health Colon and Rectal Surgery Clinic.