FDA Approves Blood Test for Colon Cancer

The US Food and Drug Administration (FDA) has approved a new blood test to detect colon cancer, which could have significant implications for increasing screening for a form of cancer that increasingly is being diagnosed in younger individuals who will subsequently require treatment by surgeons.

The blood test, Guardant Health's Shield, does not replace colonoscopies, but could provide an early warning sign that patients need to follow up with medical professionals for more definitive testing. Previously, Shield was available to physicians for approximately $900, out of pocket, but with the FDA approval, Medicare and private insurance companies are much more likely to cover the cost of the blood test.

Research published in March showed Shield was 83% effective in finding colorectal cancers through the DNA traces that the cancer leaves in the bloodstream. The test would need to be given at least every 3 years, starting at age 45, the same age it is now recommended to begin colorectal screening.

Colonoscopy is by far the most accurate way to detect colorectal cancer; however, screening rates are low, with less than 60% of eligible people having had their recommended screening. If this test increases the number of people getting screened, it could have a notable impact on detection.

In recent years, there has been a troubling rise in colon cancer in people younger than 55, with rates increasing by 1% to 2% per year in that age group. In the past 20 years, the average age of diagnosis has decreased to 66, down from 72. 

The ACS has taken note of the increased incidence of early onset colorectal cancer, dedicating this year’s Colorectal Cancer Awareness Month to the topic while following the developed in peer-reviewed literature.