Is CT Colonography Better Tolerated than Flexible Sigmoidoscopy for Colorectal Cancer Screening?
Radiology. 2018 Mar;286(3):884-886. doi: 10.1148/radiol.2017172722. Taylor SA1, von Wagner C1.
Colorectal cancer is the third most commonly diagnosed cancer worldwide. Screening is efficacious, because outcomes are improved if the cancer is detected and treated at an early stage. Furthermore, the majority of colorectal cancers arise from precursor adenomas, a transition that takes several years, and endoscopic detection and removal of these adenomas reduces cancer incidence (1). Many indirect and direct screening tests are available. Positive results from indirect tests such as fecal occult blood testing, fecal immunochemical testing, and computed tomographic (CT) colonography trigger subsequent colonoscopy; direct tests such as colonoscopy and flexible sigmoidoscopy (FS) allow detection of early-stage cancer and removal of precursor adenomas. Population participation in colorectal cancer screening is generally low, typically less than 50%. The reasons for this are complex, but perceived invasiveness of screening studies is thought to be important. For example, uptake in home kit–based fecal immunochemical testing programs is 15%–20% greater than that for colonoscopy programs (2).