The $30 million Shield test gets FDA approval

The American Cancer Society has added the Shield blood test to its colorectal cancer screening recommendations for average-risk adults aged 45 and older who decline other screenings.

Colonoscopies remain the gold standard, but blood-based tests offer a new option to increase screening rates.

In a significant update to its colorectal cancer screening guidelines,the American Cancer Society has for the first time included a blood-based test as a recommended option for average-risk adults aged 45 and older who have not completed or have declined other screening methods.

The test, known as Shield, is manufactured by Guardant Health and received FDA approval in 2024.

Two new stool-based tests join the fray

The updated guidelines, released Wednesday, also include two new stool-based tests: Cologuard Plus, an upgraded version of the existing Cologuard test, and ColoSense, developed by Geneoscopy.

These at-home tests detect molecuular markers associated with colorectal cancer and are intended to provide more accessible options for screening.

Who is the reluctant patient?

According to the American Cancer Society , blood-based tests should be recommended only to individuals who decline or do not complete preferred screening tests such as colonoscopy or stool-based tests.

Dr. William Dahut, chief scientific officer for the American Cancer Society, explained that while the blood test is not as sensitive as other methods in detecting precancerous polyps, it is a suitable option for patients who cannot or will not undergo other screenings .

'Having more options hopefully will allow more people to be screened to find cancers earlier on, and we will be able to cure more patients,' he said.

A growing awareness of the rise in colorectal cancer cases

Screening dramatically improves survival rates; more than 90% of people diagnosed with colorectal cancer at stages I and II survive at least five years.

In contrast, cancer detected at advanced stages is more difficult to treat and has lower survival rates.

Additionally, screening can help prevent colorectal cancer by identifying and removing precancerous polyps during colonoscopy or through follow-up after a positive stool test.

What auditors flagged in the May filing?

The updated guidelines reflect a growing awareness of the rise in colorectal cancer cases among younger adults.

Colorectal cancer is now the ledaing cause of cancer-related death for both men and women under age 50 in the United States.

Dr. Ursina Teitelbaum, a gastrointestinal oncology professor at the University of Pennsylvania , praised the guidelines as 'forward thinking and reality-based.'

She noted that while blood-based testing is imperfect and may miss early-stage cancers and precancerous lesions, the new recommendations acknowledge the need to broaden screening access, particularly for younger and vulnerable populations.

Dr. Scott Kopetz of MD Anderson Cancer Center added that more blood-based tests could be on the horizon, offering even more options for early detection.

The American Cancer Society emphasizes that the key is to increase overall screening rates, as many people continue to skip screening altogether due to discomfort or inconvenience.

By expanding the range of acceptable tests, the organization hopes to reduce colorectal cancer mortality.