
Blood Test Joins Colorectal Cancer Screening to Reach the Underscreened
The American Cancer Society added the Shield blood test as a recommended option for colorectal cancer screening for people who can’t or won’t have colonoscopies or stool tests. It’s not a replacement for colonoscopy; it’s intended to increase screening among the under-screened. The Shield test detects DNA fragments from tumors and, while about 83% effective at detecting existing cancer, is less reliable for early-stage disease and precancerous polyps. It costs $895 out of pocket and insurance coverage isn’t guaranteed. Most doctors stress that colonoscopy remains the gold standard and screening options vary (stool tests, Cologuard/ColoSense) with follow-up colonoscopy required if a test is positive. Experts say expanding options could boost uptake, since screening should start at 45 for average risk.













