What is the recommended screening frequency for colon cancer using Cologuard (Multitarget Stool DNA test)?

From the Guidelines

Cologuard screening for colon cancer is recommended every 3 years for average-risk individuals aged 45 to 75. This recommendation is based on the American Cancer Society's (ACS) updated guideline for CRC screening in individuals at average risk, which suggests that adults aged 45 years and older with an average risk of CRC undergo regular screening with either a high-sensitivity stool-based test or a structural (visual) exam, depending on patient preference and test availability 1. The multi-target stool DNA test (mt-sDNA), such as Cologuard, is one of the options for CRC screening, and it is recommended to be performed every 3 years.

When considering Cologuard as a screening option, it is essential to note that it is less sensitive than colonoscopy at detecting precancerous polyps, which is why it needs to be repeated more frequently than the ten-year interval recommended for colonoscopy. The test works by detecting altered DNA and blood in the stool that might indicate the presence of cancer or precancerous lesions. Some key points to consider when deciding on a screening schedule include:

• The ACS recommends that average-risk adults in good health with a life expectancy of greater than 10 years continue CRC screening through the age of 75 years 1.
• Clinicians should individualize CRC screening decisions for individuals aged 76 through 85 years, based on patient preferences, life expectancy, health status, and prior screening history 1.
• If you receive a positive Cologuard result, you should follow up with a diagnostic colonoscopy promptly.
• If you have risk factors for colorectal cancer, a colonoscopy rather than Cologuard may be more appropriate as your primary screening method.

It is crucial to consult with your healthcare provider to determine the most suitable screening schedule based on your personal health history. The ACS guideline development group applied the Grades of Recommendations, Assessment, Development and Evaluation (GRADE) criteria in developing and rating the recommendations, which provides a strong foundation for the recommended screening schedule 1.

From the Research

Screening Interval for Colorectal Cancer using Cologuard

• The US Preventive Services Task Force recommends screening for colorectal cancer starting at age 45 for average-risk individuals, but does not specify the screening interval for Cologuard 2.
• Cologuard is a multi-target stool DNA (mt-sDNA) test, which is one of the recommended screening strategies for colorectal cancer.
• The optimal screening interval for Cologuard is not explicitly stated in the provided studies, but the studies discuss the effectiveness of different screening strategies, including colonoscopy, flexible sigmoidoscopy, and fecal immunochemical tests (FITs).
• A study comparing the diagnostic yields of colonoscopy, flexible sigmoidoscopy, and FITs found that mailed multiple-round FITs detect significantly more advanced neoplasia on a population level compared with once-only flexible sigmoidoscopy or colonoscopy screening 3.
• Another study found that screening flexible sigmoidoscopy reduces incidence and mortality of colorectal cancer, with a significant reduction in mortality limited to the distal colon 4.
• The American College of Gastroenterology recommends screening for colorectal cancer using a combination of tests, including colonoscopy, flexible sigmoidoscopy, and FITs, but does not specify the screening interval for Cologuard.

Factors to Consider for Screening Interval

• The screening interval for Cologuard may depend on various factors, including the individual's risk level, family history, and previous screening results.
• The US Preventive Services Task Force recommends considering factors such as the invasiveness of the test, test performance, screening interval, accessibility, and cost when selecting a screening strategy 2.
• A study found that the reduction in colorectal cancer incidence and mortality from flexible sigmoidoscopy screening is sustained over the long term, with differences by sex and age 4.
• The optimal screening interval for Cologuard may need to be determined based on individual patient characteristics and risk factors, as well as the results of further studies comparing the effectiveness of different screening strategies.