Gut Check on Gastroenterology Archive

Last week, the Centers for Medicare and Medicaid Services (CMS) announced that they are not likely to cover virtual colonoscopy (CT colonography or CTC) for colorectal cancer screening in Medicare beneficiaries. The announcement came just months after the U.S. Preventive Services Task Force declined to recommend the test, citing insufficient evidence. Not surprisingly, the radiology community responded to both decisions with a firestorm of opposition, arguing that the ACRIN trial data proved the merits of CTC.

Is this a turf issue, or is the CMS simply taking a conservative stance pending more data? I think it’s the latter. The ACRIN study demonstrated that, although CTC is impressive in detecting larger polyps and cancer, it is not very reliable for smaller lesions (≤6 mm). Until we know for sure whether detecting and removing those lesions is important, some guideline panels will simply not be comfortable recommending CTC.

The larger issue, though, in my mind, is that CTC is being marketed as a noninvasive screening test that can accurately determine which patients should be referred for colonoscopy, and I don’t think it delivers on that promise. CTC is neither noninvasive nor inexpensive, and it is not accurate enough to be used population-wide as an initial screening test. Furthermore, it is associated with radiation exposure. Overall, it is a poor substitute for the type of screening test we really need, and I doubt that the Medicare population will be harmed in any way if the CMS decides not to cover it.

My hope is that the power of proteomics will soon be harnessed to assay for proteins produced by neoplasms and thus direct patients to colonoscopy by a simple stool or blood test.