Colonoscopic findings in first-degree relatives of patients with colorectal cancer: a population-based screening program.

BACKGROUND: A screening colonoscopy is recommended in first-degree relatives (FDRs) of colorectal cancer patients; few prospective, controlled studies have evaluated colorectal findings in a population-based screening program.
OBJECTIVE: To evaluate the prevalence of colorectal neoplasia (adenomas and adenocarcinomas) in this increased-risk population, to compare it with that of average-risk individuals, and to identify features that might allow risk stratification for neoplasia among FDRs.
DESIGN: Cross-sectional study.
SETTING: Population-based screening program in Trentino, Italy. PATIENTS: FDRs of colorectal cancer patients between 45 and 75 years of age with no history of hereditary colorectal cancer syndromes or inflammatory bowel disease. CONTROLS: Average-risk individuals undergoing screening colonoscopy. INTERVENTION: Screening colonoscopy.
RESULTS: Neoplasia was found in 33.4% of 1252 FDRs and in 30.3% of 765 controls; advanced neoplasia was found in 11.3% of FDRs and in 6.3% of controls. Odds ratios (ORs) from the multivariate logistic regression analysis adjusted for age, sex, cecal intubation rates, and colon cleansing showed an increased risk of advanced neoplasia (OR 2.41; 95% CI, 1.69-3.43; P < .0001) in FDRs. Age older than 56 years (OR 1.83; 95% CI, 1.15-2.99; P = .013) and male sex (OR 2.17; 95% CI, 1.39-3.10; P < .001) are independent predictors of advanced neoplasia. LIMITATIONS: Italian subjects living in the same geographic area; of 4301 FDRs, 2521 were excluded.
CONCLUSIONS: The increased risk of advanced neoplasia supports the current recommendation for colonoscopic screening in this group; age and sex may assist in risk stratification of these individuals.