Misses most precancersFinds only 13.7% of advanced precancerous lesions, so unlike colonoscopy it rarely prevents cancer.
Guideline and payer statusA $500M milestone hinges on a USPSTF A or B rating; ACS lists blood tests only for people who decline other tests.
Physics limits
Too little tumour DNA early onSmall, early tumours and polyps shed almost no DNA into blood, so blood tests are physically limited in catching the earliest, most curable lesions.
Specificity costs colonoscopiesAt 90% specificity, about 1 in 10 healthy people screened gets a false alarm and a colonoscopy, a trade-off that grows with population screening.
How it works
4 parts
Shed DNA
Tumours leak DNA into blood
Dying cancer cells release DNA fragments; a few copies circulate among billions from healthy cells.
Methylation
Read the chemical tags
Cancer DNA carries distinctive methyl marks; the test reads them at single-letter resolution.
Multiomics + AI
Combine signals
Machine-learning models weigh DNA and other blood markers to call a sample positive or negative.
Follow-up
Positive means colonoscopy
The test triages; a colonoscopy confirms and removes polyps or cancer.
Blood tests for cancer screening, SimpleScreen CRC
Brisbane, California company that reads DNA methylation and other signals in blood to screen for cancer. Its colorectal test SimpleScreen won FDA approval in July 2026 and is sold by Abbott.
SimpleScreen CRC: FDA approved 27 Jul 2026 for average-risk adults 45+, the second blood test after Guardant's Shield.
Abbott (which bought Exact Sciences) sells it in the US; deal worth up to $885M to Freenome.
Listed on Nasdaq (FRNM) in July 2026 via a SPAC, raising about $310M.