Cologuard Test: How It Works, vs. Colonoscopy, Cost, and More

Cologuard is the only stool-DNA screening test for detecting colon cancer that is approved by the Food and Drug Administration (FDA). Cologuard looks for changes in your DNA that could indicate the presence of colon cancer. Cologuard also checks for precancerous polyps that might be present in your colon.

Cologuard is gaining popularity because it's far less invasive, and more convenient, than the traditional colonoscopy test.

There are certainly some benefits to the Cologuard test for cancer screening, but there are drawbacks, too, including concerns about its accuracy. Keep reading to found out if you should consider the Cologuard test to screen for colon cancer.

Colon cancer is the third most common cancer in the United States, with the American Cancer Society (ACS) estimating that over 100,000 new cases will be diagnosed this year.

Even if you have no symptoms or family history of colorectal cancer, which puts you at an 'average' risk, doctors typically suggest you start screening at age 45 (ACS recommendation) or 50 (U.S. Preventive Services Task Force [USPSTF] recommendation).

Cologuard tests for colon cancer by identifying abnormal DNA and traces of blood that precancerous polyps and colon cancer can cause.

Your doctor will need to prescribe the test for you before you're able to order a Cologuard kit. You can fill out a form on the company's website that generates a customized order form for you to bring to your doctor.

If you're taking the Cologuard test, here's what to expect.

1. You'll receive a kit that includes all that you need to collect a stool sample with minimal contact with your stool. The kit includes: a bracket and collection bucket, a probe and lab tube set, a preservative solution that will preserve your sample during shipping, and a pre-paid shipping label for sending the box back to the lab.
2. Using a special bracket and collection bucket that comes with the kit, have a bowel movement on the toilet that goes directly into the collection container.
3. Using a plastic probe enclosed with the kit, also collect a swab sample of your bowel movement and place that in a special sterilized tube.
4. Pour the preservative solution included in the kit into your stool sample, and screw its special lid on tightly.
5. Fill out the form that asks for your personal information, including the date and time your sample was collected.
6. Put all collected samples and information back in the Cologuard box and ship it back to the lab as soon as possible.

Cologuard is covered by many health insurance companies, including Medicare. If you're eligible (between the ages of 50 and 75) for colon cancer screening, you may be able to get Cologuard without any out-of-pocket expense.

If you don't have insurance, or if your insurance won't cover it, the maximum cost of Cologuard is $649.

The target demographic for the Cologuard test is people who have an average risk and should be getting tested for colon cancer on a regular basis.

The USPSTF recommends that adults in the United States between the ages of 50 and 75 get screened regularly for colon cancer. The ACS recommendation is to begin screening at age 45.

If you're at an increased risk for colon cancer because of your ethnicity or family history, speak with your doctor about beginning screening even earlier.

After the lab evaluates your stool sample, Cologuard test results are sent to your doctor. Your doctor will go over the results with you and address any next steps for further testing if you need it.

Cologuard test results simply show a 'negative' or a 'positive.' Negative test results indicate that there was no abnormal DNA or 'hemoglobin biomarkers' found in your stool sample. In plain English, that just means that there's no reason to suspect colon cancer or precancerous polyps are in your colon at this time.

If you get a positive Cologuard result, something abnormal was present in the test. False positives happen in Cologuard tests frequently — in fact, up to 10 percent of positive results from Cologuard may be false. If you have a positive result, your doctor will recommend following up with a colonoscopy test.

While Cologuard and a colonoscopy test for similar things, they take two different approaches. Cologuard tests for the symptoms of colon cancer and polyps. When your doctor performs a colonoscopy, they're trying to find the polyps themselves.

Colonoscopy does carry a low risk of complications, like reactions to sedatives or possible puncturing of your bowel. Cologuard carries no such risks.

On the other hand, Cologuard can sometimes miss precancerous polyps in its screening, which is called a false negative. It also carries a high risk of false positives, which a colonoscopy does not.

Cologuard and a colonoscopy can be used together to screen for colon cancer. Cologuard works as a noninvasive, first-line test for people at risk for colon cancer. Positive results from Cologuard indicate that further testing is needed, while people with a negative test result can choose to avoid a colonoscopy.

The Cologuard test has several obvious benefits over other kinds of tests.

It can be done at home, which cuts back on time in waiting rooms or in the hospital having an exam.

Some people are hesitant about the colonoscopy procedure because it may require general anesthesia. Cologuard allows you to be screened without having any anesthesia. However, if your Cologuard tests abnormal it should be followed up with a colonoscopy.

Cologuard also doesn't require any preparation. You don't need to stop taking medications or fast before you take a Cologuard test. The important point is that you're getting screened.

There are some drawbacks to the Cologuard test, mostly involving its accuracy.

Stool sample tests are not as accurate as a colonoscopy when it comes to detecting precancerous polyps and lesions.

Eating certain foods prior to a Cologuard test, such as red meat, horseradish, or turnips, can result in a false positive result. False positives can create a lot of unnecessary stress and worry while you wait for follow-up testing. The high levels of false positives associated with Cologuard make some doctors wary of them.

Since Cologuard testing is somewhat new, there's not any long-term data available as to how this screening method will impact your long-term outlook if you do end up having colon cancer.

The cost of Cologuard is quite a substantial obstacle if you don't have insurance coverage that includes this type of screening.

Colon cancer is treatable, but early detection is an important part of survival rates for people who have it. Colon cancer that's detected at its earliest stage has a 90 percent survival rate five years after diagnosis.

Once colon cancer has progressed to stage 3 or later, positive outcomes decline sharply. For these reasons, the CDC recommends screening tests every three years for people over 50.

You may want to address concerns, fears, and questions you have about both the colonoscopy and Cologuard screening methods at your next routine visit.

Don't be shy when it comes to speaking up about colon cancer prevention and screening. Start the conversation by asking about your overall risk for colon cancer based on your health history, or by directly asking your doctor's thoughts on Cologuard and its accuracy.