[Detection of polyps, adenomas, advanced adenomas and adenocarcinomas in patients between 45 and 49 years]

BACKGROUND. Colorectal cancer (CRC) can be prevented. Colonoscopy is the first-line procedure for screening in average risk population. In 2002, Imperiale evaluated people between 40 to 49 years and reported that adenomas and advanced adenomas presented in 8.5% and 3.5% of cases, respectively. Currently, no recommendations for CRC screening in this population have been made.

To estimate the prevalence ofpolyps, adenomas, advanced lesions and adenocarcinomas in the 45- to 49-year-old population.

We included consecutive adults between 45 and 49 years old who performed colonoscopy because of gastrointestinal signs or symptoms. Exclusion criteria were high risk for CRC, incomplete VCC and/or previous evidence of colonic lesions. The study was conducted in a gastroenterology center from Buenos Aires, between September 2010 and October 2011. The design was prospective and cross-sectional. Polyethylene glycol (PEG) lavage solution or phosphates were usedfor cleansing. Colonoscopies were performed under sedation with Olympus equipment. The protocol was approved by the local IRB. 95% confidence intervals (95% CI) were estimated.

814 patients were evaluated and 764 were included, 440 (57%) were women and the average age was 47 years. The global prevalence of polyps was 20% (160 cases, 95% CI 18%-24%). The global prevalence of adenomas was 14% (107 cases, 95% CI 11%-16%). The prevalence of advanced adenomas was 5% (39 cases, 95% CI 4%-7%) and the prevalence of adenocarcinoma was 0.1% (1 case, 95% CI 0%-0.7%).

The prevalence of lesions in this population is lower than that in the average risk population. At the moment we do understand that there is no evidence to recommend CRC screening in 45- to 49-year-old individuals.