Improved stool DNA test

Currently available stool DNA testing creates the possibility of false-negative results — results that indicate no cancer is present when it actually is. That's because tests screen for a limited number of DNA mutations in your stool.

While a negative stool DNA test could mean you don't have colon cancer, it could also mean that you have DNA changes that haven't yet been attributed to colon cancer. However, as researchers learn more about the types of DNA changes that are involved in colon cancer, this type of colon cancer screening may become more effective.

The effectiveness of stool DNA testing kits has varied in clinical trials. Studies found stool DNA test kits to be 62 percent to 97 percent effective in detecting cancers and 27 percent to 82 percent reliable in detecting large precancerous (adenomatous) polyps. One large clinical trial revealed that the stool DNA test is more effective at detecting colon cancer than is the FOBT.

Still, it's hoped that such noninvasive testing will prompt more people to seek colon cancer screening. So researchers are continuing to look for ways to improve the accuracy of stool DNA testing.