IARC Handbook of Cancer Prevention Vol. 17 - Colorectal Cancer Screening

Abstract

The IARC Handbook of Cancer Prevention conduct evidence-based expert evaluations on the cancer preventive effects of interventions and strategies for primary and secondary prevention. In November 2017, 23 experts from 15 countries met at the International Agency for Research on Cancer in Lyon, France to evaluate different methods of screening for CRC. Evaluations were conducted for the stool-based tests of occult blood (guaiac fecal occult blood test, and immunochemical fecal test), endoscopic techniques (colonoscopy and sigmoidoscopy) and computed tomographic (CT) colonography. The Working Group critically reviewed all available evidence from randomized controlled trials, observational studies and modeling studies, and assessed the benefits in reducing mortality and incidence, and the benefit-harm ratio taking into account potential adverse effects. The Working Group also reviewed the literature on related topics, including availability of CRC screening worldwide, determinants of participation to screening, emerging CRC screening techniques and screening in high-risk groups. Overall, there is sufficient evidence that screening for colorectal cancer with stool-based tests of occult blood or with endoscopic techniques decreases the risk of colorectal cancer mortality; there is also sufficient evidence for a positive benefit-harm ratio with these methods, although colonoscopy may induce more substantial harms. With CT colonography, evidence for a reduction in colorectal cancer incidence and/or mortality is limited, and a minority of the Working Group rated the evidence as inadequate.