Prevalence of colorectal cancer and its precursor lesions in symptomatic and asymptomatic patients undergoing total colonoscopy: results of a large prospective, multicenter, controlled endoscopy study

BACKGROUNDColorectal cancer (CRC) is the second most common cancer in Germany. Screening colonoscopies have been offered in Germany since 2002. However, validation of screening programs for CRC relies on estimates up to date. OBJECTIVEThe aim of this study was to analyze the influence of the risk factor tumor-suspicious symptoms on the prevalence of CRC and its precursor lesions in patients at least 55 years of age undergoing colonoscopy in comparison with an age-matched and sex-matched control population undergoing screening colonoscopy. DESIGNMulticenter, prospective, controlled colonoscopy study. SETTINGIntegrated care program of 49 gastroenterological practices in collaboration with a health insurance company and the screening colonoscopy program in Hesse, Germany. PATIENTSIn total, 1075 symptomatic and 5375 asymptomatic participants were matched for age and sex (1 5) from 1 October 2008 to 30 September 2010. MAIN OUTCOME MEASUREMENTSDetection of CRC and its precursor lesions. RESULTSOverall, the prevalence of CRC was significantly equivalent in both the symptomatic (n=13/1075, 1.21%) and the control group [n=55/5375, 1.02%, 95% confidence interval (CI) for the difference[−0.46%, 0.83%], P=0.0002, equivalence test with δ=1.5%], respectively. Advanced adenomas were observed in significantly fewer symptomatic patients (61/1075, 5.67%) compared with 432/5375 matched asymptomatic screening participants (8.03%, 95% CI for the difference[−3.98%, −0.74%], P=0.0094, difference test). Finally, polyps were found significantly less often in symptomatic patients (n=269/1075, 25.0%) than in matched screening participants (n=1807/5375, 33.6%, 95% CI for the difference[−11.53%, −5.66%], P