New Colon Cancer Blood Test: Is It an Effective Alternative to a Colonoscopy?

Nothing beats a colonoscopy for colon cancer prevention. But for people without easy access or who are reluctant to undergo the procedure, a blood test has now been added as an acceptable screening option.

To be clear, a blood test is not a replacement for a colonoscopy, which remains the gold standard for detecting and preventing colon cancer. But it is estimated that a third or more of the U.S. population is not following recommended screening guidelines. Many of them may live in rural, underserved areas.

This screening gap is particularly troubling in the fight against colon cancer. Despite being largely preventable with early detection, the disease is the second-leading cause of cancer-related deaths in the U.S., claiming more than 50,000 lives every year.

How the Colon Cancer Blood Test Works

Hoping to reduce the screening shortfall, the American Cancer Society has revised its guidelines. A colonoscopy is still the top recommendation, followed by stool-based tests. But for those who opt against those options, a blood test represents a chance to catch colon cancer that might otherwise be missed until it has progressed significantly.

The blood test is a relatively new option, approved in 2024 by the FDA. The test involves collecting a small sample of your blood, which is tested for the presence of DNA changes that could indicate cancer or pre-cancerous cells.

The blood test is a less desirable option because it isn’t as effective at detecting those precancerous growths – polyps that develop on the lining of your large intestine. This dampens the chances of catching colon cancer before it can start or during its earliest stages, when it is much easier to treat.

New Colorectal Cancer Screening Guidelines: When Should You Start?

In general, the U.S. has done a solid job of lowering colon cancer rates in recent decades. Death rates have dropped by about 1.5 percent each year during the past ten years. This effort has been boosted both by lifestyle improvements and better screening.

Yet all is not well. Going against the overall positive trend has been a disturbing increase in colorectal cancers in adults under the age of 50. That group represents more than 10 percent of new colon cancer cases each year. Researchers aren’t sure what’s driving this trend, though it is suspected to be a combination of factors, including lifestyle and diet.

Hoping to counter the increase, the U.S. Preventive Services Task Force – charged with making recommendations for screenings and preventive medicine – changed its guidelines on colon cancer screening. Adults are now urged to start regular colon cancer screenings at age 45, continuing until age 75.

How often you should get screened varies, based on your screening tool and your colon cancer risk factors. Talk with your doctor to get a better understanding of how you should approach your screening schedule.

Comparing Your Options: Colonoscopy vs. Stool Tests vs. Blood Tests

·      Colonoscopy: The colonoscopy remains the top choice because of its effectiveness at finding and removing polyps, which can be analyzed in the lab. The procedure allows your doctor to carefully examine the lining of your large intestine, using high-definition video. These tests are recommended once every 10 years, unless you are at high risk for colon cancer. If you have a family history of colon cancer or have a large number of polyps, your doctor may recommend more frequent screenings.

·      Stool-based test: These tests involve collecting a sample of your stool and sending it in for analysis. These tests look for signs of blood or changes in your DNA that could be related to colon cancer. Depending on the test type, these need to be repeated every one to three years. And if anything abnormal shows up, you will need to follow up with a colonoscopy.

·      Blood test: This newest option is recommended to be repeated every three years. As with stool-based tests, a colonoscopy will be needed if there are abnormalities. This option is less likely to prevent cancer from gaining a foothold in your colon. But it can help catch cancer before it grows substantially.

It is unclear how health insurers will react to the American Cancer Society’s new guidelines. Officially, insurers are only required to cover services deemed important by the U.S. Preventive Services Task Force, which currently does not include blood tests for colon cancer screening.

This content is not AI generated.