Abstract
PURPOSE: The aims of our study were to investigate the prognostic impact of the rate of preoperative serum carbohydrate antigen 19-9/bilirubin (CA19-9/BR) on patients with extrahepatic bile duct cancer. PATIENTS AND METHODS: We collected clinical data from 89 patients who underwent surgery for extrahepatic cholangiocarcinoma (ECC) at Peking Union Medical College Hospital between January 2012 and December 2017. The Kaplan-Meier analysis for univariate analysis and the Cox proportional hazards models for multivariate analysis were used to determine possible independent prognostic factors. RESULTS: CA19-9/BR was classified as elevated compared with normal based on the upper serum normal values of CA19-9 (37 U/mL) and bilirubin (1.5 mg/dL), which gives a cut-off at 25 U/mL/mg/dL. Univariate analysis showed that the overall survival of patients with a high CA19-9/BR ratio was significantly worse compared with patients with a low CA19-9/BR ratio (Hazard Ratio [HR] 2.149; 95% Confidence Interval [95% CI] 1.027-4.495; P=0.042). Multivariate analysis revealed that a high CA19-9/BR ratio (HR 3.250; 95% CI 1.165-9.067; P=0.024), low differentiation (HR 3.551; 95% CI 1.231-10.244; P=0.019), and positive margin (HR 2.555; 95% CI 1.111-5.875; P=0.027) remained independent prognostic factors after adjusting for age at diagnosis, maximal diameters, and other possible factors. CONCLUSION: The preoperative CA19-9/BR ratio is a good prognostic factor in predicting survival in ECC patients and closer follow-up is recommended in patients with a higher CA19-9/BR ratio before surgery.