To the Editor: Dr Regge and colleagues1 stated that because CT colonography is less invasive and thus more tolerable, it may increase adherence to colorectal cancer screening. However, this may not be true.
Assume that one 10-year cycle would require 2 CT colonography screenings vs 1 optical colonoscopy, 20% of CT colonography-screened patients need an optical colonoscopy after CT colonography for each 5-year cycle, and 1 half-day of work would be lost for CT colonography and 1 day lost for optical colonoscopy. In that case, total time off work would be 1.4 days for those screened with CT colonography vs 1 day with colonoscopy; those screened by CT colonography would experience 2.4 colon cleansing procedures vs 1 for optical colonoscopy. It seems unlikely that patients would adhere better to CT colonography screening. Prospective studies are required to answer this question.
Pisarik P. Computed Tomographic Colonography for Detecting Advanced Neoplasia. JAMA. 2009;302(14):1527-1529. doi:10.1001/jama.2009.1435