How Do Novel CRC Blood Tests Fare Against Established Tests?

TOPLINE:
Novel first-generation cell-free DNA blood (cf-bDNA) tests for colorectal cancer (CRC) cost more and are less effective than colonoscopy or stool tests, a new analysis suggests.
METHODOLOGY:
Researchers estimated the clinical and economic impacts of emerging blood- and stool-based CRC screening tests with established alternatives in average-risk adults aged 45 years and older.
The established screening tools were colonoscopy, a fecal immunochemical test (FIT), and a multitarget stool DNA test (MT-sDNA, Exact Sciences Cologuard).
The four emerging screening methods were two cf-bDNA tests (Guardant Shield and Freenome); an enhanced, a next-generation multitarget stool test (ngMT-sDNA), and a novel FIT-RNA test (Geneoscopy ColoSense).
TAKEAWAY:
Assuming 100% participation in all screening steps, colonoscopy and FIT yielded reductions of more than 70% in CRC incidence and 75% in mortality vs no screening.
The MT-sDNA test reduced CRC incidence by 68% and mortality by 73%, with similar rates for the ngMT-sDNA and FIT-RNA tests vs no screening. The cf-bDNA tests yielded CRC incidence and mortality reductions of only 42% and 56%.
Colonoscopy and FIT were more effective and less costly than the cf-bDNA and MT-sDNA tests, and the MT-sDNA test was more effective and less costly than the cf-bDNA test.
Population benefits from blood tests were seen only in those who declined colonoscopy and stool tests. Substituting a blood test for those already using colonoscopy or stool tests led to worse population-level outcomes.
IN PRACTICE:
“First-generation novel cf-bDNA tests have the potential to decrease meaningfully the incidence and mortality of CRC compared with no screening but substantially less profoundly than screening colonoscopy or stool tests. Net population benefit or harm can follow incorporation of first-generation cf-bDNA CRC screening tests into practice, depending on the balance between bringing unscreened persons into screening (addition) vs shifting persons away from the more effective strategies of colonoscopy or stool testing (substitution),” the authors concluded.
SOURCE:
The study, with first author Uri Ladabaum, MD, MS, Stanford University School of Medicine, California, was published online in Annals of Internal Medicine.
LIMITATIONS:
Limitations included test-specific participation patterns being unknown over time. 
DISCLOSURES:
Disclosure forms for the authors are available with the article online. Funding was provided by the Gorrindo Family Fund.
 
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