American Cancer Society Adds Blood and Stool Tests to Colon Cancer Screening Guidelines

The American Cancer Society announced new recommendations on Wednesday that add three screening tests for colorectal cancer. The tests include a blood test called Shield and two stool tests, Cologuard Plus and ColoSense. The organization said the changes aim to increase screening rates among adults aged 45 to 75.

Current data show less than half of adults aged 45 to 49 have completed recommended screenings.

Shield, manufactured by Guardant Health, received FDA approval in 2025. Studies indicate it detects about 83 percent of colorectal cancers found during colonoscopy. Cologuard Plus and ColoSense detect cancer more than 90 percent of the time when performed every three years. Both tests examine stool for DNA or RNA markers associated with tumors.

Colonoscopy remains the most effective method because it allows doctors to remove precancerous polyps during the procedure. The American Cancer Society continues to recommend it as the preferred option. Robert Smith, senior vice president of early cancer detection science at the American Cancer Society, said any screening is better than none.

He noted that positive results from blood or stool tests require follow-up colonoscopy. Dr. Andrea Cercek of Memorial Sloan Kettering Cancer Center said patients should not substitute newer tests for colonoscopy if they are able to undergo the procedure.

She cited the risk that undetected polyps could progress to cancer between screenings. Medicare covers Shield and Cologuard Plus. ColoSense coverage remains under review. Most major insurance plans cover the new tests for eligible adults.