Long-lasting reduction of risk of colorectal cancer following screening endoscopy

Several studies have suggested that incidence and mortality of colorectal c ancer (CRC) may be strongly reduced for up to 10 years by endoscopic screen ing with removal of precancerous lesions, but so far there are no data on r isk reduction beyond this period. We assessed long-term reduction of CRC ri sk following screening endoscopy in a statewide population-based case-contr ol study in Saarland, Germany. Lifetime history of screening endoscopy was compared between 320 cases with CRC aged 45-80 and 263 controls with other forms of cancer recruited from the same population. Potential confounding f actors were controlled for by multiple logistic regression. 11% of cases co mpared to 27% of controls had a history of endoscopy for screening purposes (adjusted odds ratio (OR) = 0.28, 95% confidence interval (CI): 0.16-0.48) . This strong risk reduction was also seen (OR = 0.41, 95% CI: 0.19-0.89) i n subjects who had their last screening endoscopy more than 10 years ago (m edian: 18.9 years). Long term (> 10 years since last screening) risk reduct ion appeared to be particularly strong for advanced (Dukes C or D) CRC (OR = 0.19, 95% CI: 0.06-0.64). We conclude that risk reduction by screening en doscopy is long lasting, in particular with respect to advanced CRC. (C) 20 01 Cancer Research Campaign http://www.bjcancer.com.