Abstract
BACKGROUND: Biliary tract cancer (BTC) is a rare, aggressive malignancy with increasing incidence and poor prognosis. Identifying preoperative prognostic factors is crucial for effective risk-benefit assessments and patient stratification. The prognostic nutritional index (PNI), which reflects immune-inflammatory and nutritional status, has shown prognostic value in various cancers, but its significance in BTC remains unclear. AIM: To assess the prognostic value of the preoperative PNI in BTC patients, with a focus on overall survival (OS) and disease-free survival (DFS). METHODS: Comprehensive searches were conducted in the PubMed, EMBASE, and Web of Science databases from inception to April 2024. The primary outcomes of interest focused on the associations between the preoperative PNI and the prognosis of BTC patients, specifically OS and disease-free survival (DFS). Statistical analyses were conducted via STATA 17.0 software. RESULTS: Seventeen studies encompassing 4645 patients met the inclusion criteria. Meta-analysis revealed that a low PNI was significantly associated with poorer OS [hazard ratio (HR) 1.91, 95%CI: 1.59-2.29; P < 0.001] and DFS (HR 1.93, 95%CI: 1.39-2.67; P < 0.001). Subgroup analyses revealed consistent results across BTC subtypes (cholangiocarcinoma and gallbladder cancer) and stages (resectable and advanced). Sensitivity analyses confirmed the robustness of these findings, and no significant publication bias was detected. CONCLUSION: This study demonstrated that a low preoperative PNI predicts poor OS and DFS in BTC patients, highlighting its potential as a valuable prognostic tool. Further prospective studies are needed to validate these findings and enhance BTC patient management.