Do patients with rectosigmoid adenomas 5 mm or less in diameter need totalcolonoscopy?

Background: The need for colonoscopy in the care of patients with rectosigm oid adenoma 5 mm or less in diameter is still debatable. Methods: We estimated the prevalence of proximal adenomas among 3052 consec utive subjects undergoing total colonoscopy. Rectosigmoid adenoma was class ified as diminutive (5 mm), small (6 to 10 mm), or large (greater than or e qual to 11 mm). Advanced proximal adenoma was 10 mm in diameter or larger, or with a villous component, severe dysplasia, or infiltrating adenocarcino ma. Results: Proximal adenoma was found in 212 of 2483 patients (8.5%, 95% CI [ 7.5, 9.7]) without distal neoplastic polyps, 49 of 214 (22.9%, 95% CI [17.6 , 29.2]) with diminutive, 44 of 174 (25.3%, 95% CI [19.1, 32.5] with small, and 70 of 181 (38.7%, 95% CI [31.6, 46.2]) with large distal adenoma. Adva nced proximal adenoma was found in 49 (2.0%, 95% CI [1.5, 2.6]), 8 (3.7%, 9 5% CI [1.7, 7.5]), 17 (9.8%, 95% CI [6.0, 15.4]), and 29 patients (16.0%, 9 5% [11.2, 22.4]), respectively. In patients with distal adenoma risk for pr oximal lesions increased with increasing age, size, and number of distal ad enomas (p = 0.01). Size of distal adenoma was the strongest predictor of th e presence of proximal advanced adenoma (multivariate analyses). Conclusions: In a clinical setting, the decision to perform colonoscopy sho uld take into account proximal lesions of clinical interest, life expectanc y, costs, and risks associated with the procedure. When detection of advanc ed proximal adenoma is the goal, presence of distal diminutive adenoma alon e might not be an indication for total colonoscopy.