A combined prediction model for biliary tract cancer using the prognostic nutritional index and pathological findings: a single-center retrospective study

BACKGROUND: The prognostic nutritional index, a marker of nutritional status and systemic inflammation, is a known biomarker for various cancers. However, few studies have evaluated the predictive value of the prognostic nutritional index in patients with biliary tract cancer. Therefore, we investigated the prognostic significance of the prognostic nutritional index, and developed a risk-stratification system to identify prognostic factors in patients with biliary tract cancer. METHODS: Between July 2010 and March 2021, 117 patients with biliary tract cancer were recruited to this single-center, retrospective study. The relationship between clinicopathological variables, including the prognostic nutritional index, and overall survival was analyzed using univariate and multivariate analyses. A P < 0.05 was considered statistically significant. RESULTS: The median age was 75 (range 38–92) years. Thirty patients had intrahepatic cholangiocarcinoma; 29, gallbladder carcinoma; 27, distal cholangiocarcinoma; 17, ampullary carcinoma; and 13, perihilar cholangiocarcinoma. Curative (R0) resection was achieved in 99 patients. In univariate analysis, the prognostic nutritional index (< 42), lymph node metastasis, carbohydrate antigen 19-9 level (> 20 U/mL), preoperative cholangitis, tumor differentiation, operation time (≥ 360 min), and R1–2 resection were significant risk factors for overall survival. The prognostic nutritional index (P = 0.027), lymph node metastasis (P = 0.040), and tumor differentiation (P = 0.006) were independent prognostic factors in multivariate analysis. A combined score of the prognostic nutritional index and pathological findings outperformed each marker alone, in terms of discriminatory power. CONCLUSIONS: The prognostic nutritional index, lymph node metastasis, and tumor differentiation were independent prognostic factors after surgical resection in patients with biliary tract cancer. A combined prediction model using the prognostic nutritional index and pathological findings accurately predicted prognosis, and can be used as a novel prognostic factor in patients with biliary tract cancer.