KNOXVILLE - Colorectal cancer is the second leading cause of cancer-related deaths in the U.S., despite a high survival rate when detected early. More than 50 million Americans do not complete screening, putting them at risk for fatal outcomes. So why do so many skip out on necessary screening with so much at stake?

The reason patients give is clear and across-the-board: current screening methods are invasive, disruptive, and downright unpleasant.

But that is about to change.

A medical breakthrough has led to the first FDA-approved blood test for primary screening for colorectal cancer. The test, known as Shield, is a simple but effective test that your primary care physician can administer to detect colorectal cancer before it spreads.

Guardant Health is the company behind the Shield test. Sam Asgarian, VP of Clinical Development for Screening, says this breakthrough didn’t come overnight. “Guardant Health started off a little over 12 years ago as a company focused on curing cancer with data. Recently, we researched, can we actually start detecting cancer in blood before the diagnosis? And we focused on colorectal cancer.”

About one in three Americans do not complete screening, even though the survival rate is above 90% when caught early. Three out of four people who die from colorectal cancer are not up to date on their recommended screening.

“If a tumor is in the colon, that tumor is multiplying and has to shed some of its DNA when it’s multiplying into the bloodstream,” Asgarian said. “We can pick up that signal, even though it’s a small signal, because the tumor DNA is different from normal cellular DNA.”

The test achieved FDA approval following a comprehensive study involving more than 10,000 participants, with results published in the New England Journal of Medicine. The trial cleared performance benchmarks for Medicare and the U.S. Department of Veterans Affairs (VA) Community Care Network coverage, meaning even more people will be able to access this lifesaving screening.

The test is now available in Tennessee. Anyone interested in the test should ask their physician for more information.