Is there a role for a new blood test for colorectal cancer? Elizabeth Tracey reports

Podcast: Download (Duration: 1:07 — 1.5MB)

Subscribe: RSS

A blood test can identify the majority of colorectal cancers, a new study finds, when compared with the gold standard, colonoscopy, for screening. Yet whether this test can be trusted when it says cancer is NOT present is another matter, and it isn’t good at detecting very early lesions that may develop into cancers. That’s according to Kimmel Cancer Center director William Nelson at Johns Hopkins.

Nelson: The reason we screen is to try and find not advanced colorectal cancer, we're trying to find cancers that are in a very limited stage, even some of the advanced precursors the polyps that might grow into cancers. Colonoscopy clearly sees them and it clearly saw them in this study as well. The sensitivity for those was only about 13%. What's the benefit? The colonoscopy and the tests of the stool for human blood they call fit testing, it's a very good test. Those tests have a pretty high negative predictive value even for the precursor question.            :33

For now Nelson says, stick with the tried and true for colorectal cancer screening. At Johns Hopkins, I’m Elizabeth Tracey.