Li J, Chen Q, Jin B, et al. - In order to determine the prognostic influence of the rate of preoperative serum carbohydrate antigen 19-9/bilirubin (CA19-9/BR) on patients having extrahepatic bile duct cancer, researchers performed this study utilizing clinical data from patients (n = 89) who were surgically managed for extrahepatic cholangiocarcinoma (ECC) at Peking Union Medical College Hospital between January 2012 and December 2017. They categorized CA19-9/BR as high vs normal based on the upper serum normal values of CA19-9 (37 U/mL) and bilirubin (1.5 mg/dL), which yielded a cut-off at 25 U/mL/mg/dL. Independent prognostic factors revealed in the multivariate analysis after adjusting for age at diagnosis, maximal diameters, and other possible factors were: a high CA19-9/BR ratio, low differentiation, and positive margin. For predicting survival in ECC patients, the preoperative CA19-9/BR ratio was identified as a good prognostic factor. Closer follow-up was advised for cases with a higher CA19-9/BR ratio prior to surgery.