American Cancer Society adds blood test to colorectal cancer screening options

28 May 2026 · Source balance: Centre

The American Cancer Society updated its colorectal cancer screening guidelines this week to include blood testing as a screening option for the first time. The guideline recommends blood tests only for people who decline or can't complete preferred screening methods like colonoscopy or stool-based tests. The Shield blood test, approved by the FDA in 2024, detects tumor DNA in blood but is less effective than colonoscopy at finding precancerous polyps. About one in three eligible adults aren't screened, so the Cancer Society hopes expanding testing options will increase participation. Screening should begin at age 45 for average-risk adults and continue through age 75. Experts emphasize colonoscopy remains the gold standard, and any positive blood test result must be confirmed with colonoscopy within six months. Over 108,000 new colon cancer cases and nearly 50,000 rectal cancer cases are expected this year in the US.