Abstract
INTRODUCTION: To compare metachronous colorectal cancer (CRC) and advanced adenoma (AA) risk in patients with proximal vs. distal adenomas. METHODS: We searched Pubmed, Embase, and Cochrane for cohort studies and clinical trials. Proximal adenomas were those located proximal to the descending colon. Pooled incidence rate ratios and 95% confidence intervals (CI) for CRC and AA were calculated using a random-effects model. RESULTS: Compared with patients with only distal adenomas, patients with any proximal adenoma had a higher risk of metachronous CRC (1.70, 95% CI 1.17-2.45), proximal CRC (3.65, 95% CI 1.57-8.46), and AA (1.82, 95% CI 1.41-2.34). DISCUSSION: Baseline adenoma proximal location is associated with future detection of CRC and AA.