433 Evaluation of Dutch and Swedish Risk-Stratification Scores for Incidental Gallbladder Cancer: A Secondary Analysis from a UK Feasibility Study

Abstract Aim Routine histological analysis of gallbladder specimens is standard UK practice after cholecystectomy to detect incidental gallbladder cancer (iGBC) and dysplasia. Selective histological analysis (SHA) has been proposed to reduce cost and histopathological workload. The aim of this secondary analysis was to explore the application of two international risk-stratification scores to a UK cohort of patients undergoing cholecystectomy. Method The Feasibility of Predicting Incidental gallbladder Cancer (fP-iGBC) study prospectively recruited 508 consecutive adult patients undergoing cholecystectomy for benign indications and excluding those with known pre-operative risk factors for biliary malignancy. For this secondary analysis, existing Swedish and Dutch scores were retrospectively applied to assess patient classification and histological correlation. Results The Swedish score was applicable to 501 patients (98.6%). As per original criteria, 141 (28.2%) patients aged <40 were not scored. The score classified 54 (10.8%) as low-risk, 203 (40.5%) as intermediate, and 103 (20.6%) high-risk. The high-risk group included one iGBC, one high-grade dysplasia (HGD) and three low-grade dysplasia (LGD). One HGD and three LGD were identified in the intermediate group. The Dutch score was applicable to 494 patients (97.2%). The score classified 393 (78.7%) as low risk, and 105 (21.3%) as high-risk. The high-risk group included one iGBC, one HGD and three LGD. The low-risk group included three LGD and one HGD. Conclusions Within the limitations of this underpowered secondary analysis, neither score reliably identified all cases of iGBC and dysplasia. These provisional findings reinforce the need for a robust, UK-derived and validated risk-stratification method before SHA can be safely adopted.