Optimizing Lymph Node Staging in Gallbladder Cancer: A Cutoff of 11 Nodes for Accurate Staging and Improved Survival

BACKGROUND: Gallbladder cancer (GBC) is an aggressive malignancy in which lymph node (LN) status is a key prognostic factor. Adequate LN retrieval is essential for accurate nodal staging. This study aimed to identify an LN threshold that reduces false node-negative (false N0) rates and to evaluate its association with overall survival (OS) as supportive evidence. METHODS: This retrospective study included 425 patients in a development cohort and 176 patients in an external validation cohort who underwent curative-intent surgery for GBC between 2008 and 2017. False N0 rates were estimated according to the number of retrieved LNs using a β-binomial model, and survival analyses were performed as complementary assessments. RESULTS: In both cohorts, retrieval of 11 LNs reduced the false N0 rate to approximately 11%-13% across T stages. Spline-based analyses demonstrated changes in survival patterns according to LN yield in the development cohort, with an inflection around 11 retrieved LNs, although dichotomized survival comparisons were not statistically significant in either cohort. CONCLUSIONS: Retrieval of at least 11 LNs was associated with a lower false N0 rate in GBC and may serve as a reference point for nodal staging. Survival analyses provided contextual support rather than evidence of a direct survival benefit.