New at-Home Test for Detecting Colon Cancer Available

There’s a new at-home colon cancer test on the market, Cologuard. The test, which involves sending a stool sample via a collection kit to a lab for testing, is almost as simple as going to the bathroom, but it’s leaving many people wondering: Is it effective?

“This particular test has a 92 percent sensitivity rate for detecting cancer, but only 45 percent for detecting polyps. It’s almost a coin flip as to whether it will detect polyps or not, so that’s a huge negative,” Allan Peck MD, of the TriHealth Digestive Institute, explains. “We’d rather detect polyps before you got to the cancer stage.”

On the flip side, if the test does detect polyps or other abnormalities, you’ll still need a colonoscopy screening. It also tends to generate a lot of false positives, “So it’s not a huge step forward,” he adds.

Colon Cancer Screening: An Ongoing Battle

While a colonoscopy is the most effective screening tool for detecting precancerous polyps, which are growths on the lining of the colon or rectum, Dr. Peck says only about 60 percent of people who should get their colonoscopy actually do.

Colon cancer screening is recommended if you fit the following criteria:

  • If you’re age 50 or older, unless you have a family history of colon cancer, and then you should start at age 40.
  • If you’re African American, start getting screened at age 45. 

Note: As long as nothing is detected, you should get a colonoscopy every 10 years. Your physician may recommend more frequent testing if polyps are detected.

How Does Cologuard Compare to Other Less Invasive Screening Options?

Another relatively new test for colon cancer, the Fecal Immunochemical Test (FIT), tests for hidden blood in the stool, which can be an early sign of cancer. While this test is significantly cheaper than Cologuard, which costs about $600, there’s a downside: It only detects abnormalities in the stool about 25 percent of the time.

If you do, however, decide – regardless of guideline recommendations – against a colonoscopy, Dr. Peck says to have the FIT test annually. “With this newer test at about $600 a year, I’m not sure it’s worth it.” The FIT test costs about $30 and is covered by most insurance plans.

The Bottom Line: A Colonoscopy is the Most Effective Test

A colonoscopy is about 97 percent to 98 percent effective in detecting polyps and other abnormalities. “When we do a colonoscopy, we quote a miss rate – meaning to miss something significant – 1 percent of the time,” Dr. Peck points out.

If you haven't warmed to the idea of a colonoscopy yet and are interested in an at-home test, check with your doctor to decide if it's right for you.

Tags: Cancer

Last Updated: November 5, 2014