Blood test added to colorectal cancer screening options by cancer group

Health newsBlood test added to colorectal cancer screening options by cancer groupThe updated guidelines from the American Cancer Society are meant to increase the number of people screened for colorectal cancer.Listen to this article with a free account00:0000:00The American Cancer Society added Guardant Health's Shield blood test to its list of colorectal cancer screening options.Business WireShareAdd NBC News to GoogleMay 27, 2026, 7:00 AM EDTBy Erika EdwardsFor the first time, a blood test has been added to the list of the American Cancer Society’s recommended screenings for colorectal cancer. It’s not meant to replace colonoscopies, aiming instead at catching people who might not get screened otherwise. Subscribe to read this story ad-free Get unlimited access to ad-free articles and exclusive content.“About a third of Americans are not up to date with colorectal cancer screening,” said Dr. William Dahut, chief scientific officer for the American Cancer Society. Adding a new type of test could “dramatically increase” the number of people screened for colorectal cancer, which is the nation’s top cause of cancer death in people under age 50, he said. The blood test, called Shield, from California-based Guardant Health, was approved by the Food and Drug Administration in 2024. It works by detecting DNA fragments released by cancerous tumors. The American Cancer Society recommends it only for people who can’t or won’t undergo more effective screenings like colonoscopies or stool tests.While studies have found the Shield blood test is 83% effective in finding colorectal cancers, it works best at finding more advanced disease and is significantly less effective at detecting early signs of the cancer, when it’s most treatable. Precancerous polyps don’t release those DNA fragments. And there isn’t any data yet showing whether the test can save lives in the long run. “It won’t be as good at picking up the pre-cancer areas or stage 1 cancers,” Dahut said, “but it’s...