Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community


    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

Colorectal Cancer Health Center

Font Size

Highly Accurate At-Home Colon Cancer Test Approved

DNA analysis of stool boosts accuracy rate of Cologuard to more than 90 percent, researchers say


Commonly used stool tests such as FIT (fecal immunochemical testing) rely on detecting blood in the stool. The new Cologuard test checks for blood as well as abnormal DNA, "with the advantage that some lesions, even cancers, don't bleed very much," Itzkowitz explained.

But the Cologuard test also features a DNA analysis not included in other fecal exams.

"By increasing the pick-up rate in this way," said Itzkowitz, "we found that the new test had a 92 percent sensitivity for detection of colorectal cancer. That kind of result is really unprecedented for a noninvasive stool-based screening."

The research was funded by Exact Sciences Corp., which is based in Madison, Wisc.

To assess the potential of the DNA method, nearly 10,000 men and women aged 50 and older were screened for colon cancer and precancerous polyps at one of 90 sites across the United States and Canada. All were considered at average risk for colon cancer.

Each patient was screened three ways: by means of a standard colonoscopy; a commercially available fecal test (FIT); and the new DNA test, which requires patients to collect their own stool sample at home and mail it in for laboratory analysis.

In the end, colonoscopy screenings -- considered the gold standard of colon cancer screening -- revealed colon cancer in 65 participants, while another 757 were found to have advanced precancerous lesions.

The new DNA test accurately detected 60 of those 65 cancers. The FIT test spotted only 48 cancers, with an accuracy rate of 74 percent compared to 92 percent for the new test.

The DNA test was less accurate with respect to precancerous lesions, spotting about 42 percent of cases. Yet that still topped FIT, which detected roughly 24 percent of precancerous lesions. Cologuard's sensitivity was 69 percent for precancerous polyps most likely to progress to cancer versus 46 percent for the FIT test.

However, the DNA test was more likely to falsely suggest the presence of cancer than either a colonoscopy or FIT testing.

"It [the DNA test] is not a perfect test," Itzkowitz acknowledged. "But neither is a colonoscopy. Also, I don't think we're saying that this test should be done as a replacement for a colonoscopy, but rather as an adjunct. Certainly if a person who does this test comes out with a positive reading then they will need to do a colonoscopy afterwards to confirm it."

Today on WebMD

Colorectal cancer cells
The right diagnosis is the most important factor.
man with a doctor
Our health check will steer you in the right direction.
sauteed cherry tomatoes
Fight cancer one plate at a time.
bladder cancer x-ray
Do you know the warning signs?
Colon vs Rectal Cancer
New Colorectal Treatments
can lack of sleep affect your immune system
Cancer Facts Quiz
Virtual Colonoscopy
Picture of the Colon
Vitamin D