Follow-up of gallbladder polyps in a high-risk population of gallbladder cancer: a cohort study and multivariate survival competing risk analysis

Background: The risk of neoplasia in gallbladder polyps seems to be low, but the evidence from populations at high-risk of gallbladder cancer is limited. We aimed to estimate the risk and to identify the factors associated with neoplastic polyps in a high-risk Hispanic population. Methods: A retrospective cohort was recruited between January 2010 and December 2019 at a Chilean university center. Multivariate survival analyses were conducted. Fine-Gray models were fitted to account for competing risks. Covariate adjustment was conducted using propensity scores. The main outcome was the development of gallbladder adenomas or adenocarcinoma. Results: Overall, 748 patients were included, 59.6% underwent cholecystectomy. The median followup of patients not subjected to cholecystectomy was 54.7 months (12-128.6 months). Seventeen patients (2.27%) developed the outcome. After adjustment by age, sex, intralesional blood flow, lithiasis and gallbladder wall thickening, only polyp size (>10 mm, adjusted-HR: 15.01, 95%CI: 5.4-48.2) and number of polyps (>3 polyps, adjusted-HR: 0.11, 95%CI: 0.01-0.55) were associated with neoplasia. Conclusion: In a Hispanic population at high-risk for gallbladder cancer, gallbladder polyps seem to have a low risk of neoplasia. Polyp size was the main risk factor, while having multiple polyps was associated with an underlying benign condition.