The future of colorectal cancer screening: Are we ready for a simple blood test?

Colonoscopy and stool-based DNA tests always have been standard options for colorectal cancer screening. Yet despite being one of the most cost-effective noninvasive screening methods, annual immunochemical stool testing sees poor adoption because of the inconvenience of collecting a stool sample.

In fact, only 45% of eligible individuals undergo any form of stool-based screening, and adherence to these tests remains especially low in certain populations.

In July 2024, the Food and Drug Administration approved the first blood-based test for colorectal cancer screening – the Shield Test. This test detects specific DNA changes in the blood associated with colorectal cancer, offering 83% sensitivity and 90% specificity for advanced cancers.

The test is now covered by many insurance providers, including Medicare. The Shield Test presents an accessible option, particularly for underserved populations and those in remote areas as it can be easily administered by primary care physicians and midlevel providers.

While colonoscopy remains the gold standard, the simplicity, affordability and accessibility of blood-based screening make it a promising alternative. Over time, as these tests evolve and improve in sensitivity, they could become a major noninvasive screening tool.

However, at this time, they should not replace the traditional methods such as colonoscopy and stool DNA testing.

The good news: Since 2000, the incidence of colorectal cancer has declined by 40% in adults older than 59, thanks in part to public awareness campaigns that have led to increased screenings and advancements in treatment. Yet we can do better. Colorectal cancer is largely preventable, but cases are rising in younger populations.

My message to everyone: Now is the time for action. Live a healthy lifestyle with a balanced diet, exercise regularly and avoid weight gain. If you are 45 or older, or at high risk, get a colorectal cancer screening because early detection saves lives.

Prevention is always better than cure. Let us work together to eradicate colorectal cancer once and for all.

• Pankaj Vashi, MD, AGAF, FASPEN, is the medical director of gastroenterology/nutrition and metabolic support at City of Hope Chicago. Dr. Vashi works in the Chicago Gastrointestinal Cancer Center as part of a multidisciplinary team of cancer experts.