Prognostic significance of tumor budding in biliary tract cancer.

Background: Tumor budding is a significant prognostic indicator for poor survival of several solid tumors. However, due to the lack of a standard scoring system, its clinical application for biliary tract cancer (BTC) is limited.

Objective: To identify the prognostic significance of tumor budding in BTC.

Results: Tumor budding was associated with poor histologic differentiation, lymphovascular invasion, perineural invasion, lymph node metastasis, positive surgical margin, etc. Tumor budding was a predictor of poor OS in univariate (HR: 4.36; 95% CI 3.15 to 6.02; P < 0.001) and multivariate (HR: 2.95; 95% CI 2.28 to 3.80; P < 0.001) analysis. Similarly, it was also a predictor of poor DFS in univariate (HR: 3.26; 95% CI 2.12 to 4.99; P < 0.001) and multivariate (HR: 3.21; 95% CI 1.90 to 5.40; P < 0.001) analysis. In addition, tumor budding was also associated with advanced T-stage, poor histologic differentiation, lymph node metastasis, positive resection margin, lymphatic invasion, vascular invasion, and perineural invasion.

Conclusion: Results of our study have shown that tumor budding is a strong predictor of poor survival for BTC. The clinical utility of tumor budding as a prognostic marker for BTC should be considered after developing a standard international consensus based on the current evidence.