INDIANAPOLIS (WISH) – This week, the United States Food and Drug Administration approved Guardant’s Shield blood test to screen for colon cancer in average-risk Americans 45 to 75 years old.

Average-risk individuals are those without a personal or family history of colon cancer.

The test costs almost $900 out-of-pocket but recent FDA approval is expected to make it more affordable with insurance coverage.

During Guardant’s study, the test caught 83% of cancers, similar to stool testing; however, it does not detect precancerous growths or polyps.

Precancerous growths can be caught during a colonoscopy, which allows for direct visualization, biopsy and removal of polyps. Unfortunately, many people are reluctant to get a colonoscopy due to the time away from work, the large volume of liquid laxative prep drunk the day before the exam and the need for a driver on exam day. Fortunately, Guardant’s test, similar to stool testing, offers a less invasive alternative. 

Has screening decreased rates of colon cancer? 

Over 150,000 Americans are diagnosed annually and over 50,000 will die each year. Rates have been decreasing since the 1980s but young adults have the highest increasing rate of disease, according to the Colorectal Cancer Alliance. Rates are also higher in Black Americans, who are 15% more likely to be diagnosed and 35% more likely to die from disease. For this reason, Black Americans should be screened starting at 40 years old.

Despite screening increasing the rate of early detection and preventing disease, only 60% of eligible Americans are routinely screened. The hope is that Guardant’s test can help improve this.  

How often should one be screened for colon cancer? 

Colonoscopies are performed every 10 years, if normal. Stool DNA testing should be performed every three years, if normal. Guardant’s Shield blood test should also be performed every three years. If either of the latter two tests are abnormal, follow-up colonoscopy is recommended. Individuals should know that this scenario could lead to more out of pocket expenses.  

How can the risk of colon cancer be reduced? 

• Eating a diet high in fiber: vegetables, fruits, whole grains (if tolerable), beans 

• Reducing intake of red meat and processed meats like bacon, sausage and deli meat 

• Limiting alcohol intake 

If you are interested in having the Guardant Shield blood test performed or an alternative colon cancer screening exam, please speak with your primary health care professional.