US Gives Green Light to First Blood Test for Colon Cancer. How Does It Work? – National

US health authorities on Monday approved a unique blood test for colorectal cancer, offering a new way to detect a leading cause of cancer deaths.

Test maker Guardant said the Food and Drug Administration has approved its Shield test for screening adults 45 and older at average risk for colorectal cancer. The test is not a replacement for colonoscopies, but offers a noninvasive approach to screening.

2:12
Health Affairs: Reason for rising cancer rates among young people unclear, American Cancer Society reports

Doctors can already prescribe Shield to patients as a lab test, with an $895 co-pay. But the FDA approval is expected to lead to increased coverage by private and government insurance plans.

The test looks for DNA fragments shed by tumor cells and precancerous growths. In a study published in March, the test found 83% of cancers but only a few of the precancerous growths found by colonoscopy, the gold standard for colorectal cancer screening. The test missed 17% of cancers, a performance comparable to that of stool tests.

4:42
Colorectal cancer screening

In addition to detecting tumors, a colonoscopy can also prevent the disease by removing precancerous growths, also called polyps.

Receive weekly health news

Receive the latest medical news and health information every Sunday.

By submitting your email address you indicate that you have read and agree to the Global News terms and conditions. Conditions And Privacy Policy.

But some people avoid the test because of the hassle of getting off work or the preparations it entails the day before, which include drinking a strong laxative to empty the bowels. In the U.S., screening is recommended for healthy adults ages 45 to 75 who are at average risk for colorectal cancer.

Doctors can administer the Shield test after a simple blood draw, Guardant said in a statement. The company plans to launch its product “in the near future.”

In the United States, the annual screening rate for colorectal cancer is nearly 60 percent. That is well below the goal of the American Cancer Society and others, which is 80 percent of eligible adults.

The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Science and Educational Media Group. The AP is solely responsible for all content.