One negative colonoscopy associated with a significant reduction in colorectal cancer risk.

Abstract

An observational study published in the Annals of Internal Medicine1 found significant reductions in both colorectal cancer (CRC) incidence and mortality associated with a single negative high-quality screening colonoscopy. The findings indicate an 84% reduction in incidence and a 90% reduction in mortality for up to 17.4 years. As a result, the study authors suggest that the currently recommended 10-year screening interval is safe and could safely be extended. Under current guidelines, average-risk individuals aged 50 years or older who have previously had negative colonoscopy results are recommended to undergo screening every 10 years. That recommendation is based on estimates for how long it takes for adenomas and carcinomas to develop. However, longterm data are lacking on optimum follow-up intervals. The study was conducted by researchers from the Maria Sklodowska-Curie National Research Institute for Oncology in Warsaw, Poland. They analyzed a screening registry of 165,887 people and assessed both long-term CRC risk and CRC death after a single negative low- or high-quality screening colonoscopy. Their findings show that although a single negative screening colonoscopy was associated with significantly reduced CRC incidence and mortality during the 17-year screening period, only a high-quality colonoscopy led to a profound and stable reduction. Among women, high quality was key for long-term efficacy in screening colonoscopy in the proximal colon. These findings are particularly important because previous studies have questioned the efficacy of colonoscopy in the proximal colon as well as screening sigmoidoscopy in women.