Geriatrician, Hospitalist, Patient Advocate, Healthcare Educator

Blood Test for Colorectal Cancer Screening

Per Allison Aubrey in NPR “A simple blood test can detect colorectal cancer early, study finds”.

“At a time when colorectal cancer is on the rise, a new study finds the disease can be detected through a blood test.

The results of a clinical trial, published Wednesday, in The New England Journal of Medicine, show that the blood-based screening test detects 83% of people with colorectal cancer. If the FDA approves it, the blood test would be another screening tool to detect the cancer at an early stage.

The test, developed by Guardant Health, can be done from a blood draw. The company says its test detects cancer signals in the bloodstream by identifying circulating tumor DNA. “

This study showed the blood test is less effective in detecting the earliest signs of colorectal cancer and only found 13% percent of earlier stage polyps. It would be nice if it could pick up on earlier stages but the test works by detecting tumor DNA making it harder to detect precancerous polyps. Regardless, this would be a much more easier test to get than what we have available. Although the gold standard for screening is colonoscopy, this blood test, if gets FDA approval, may provide an alternative to colonoscopy and stool testing in some individuals.