Risk factors to differentiate between benign proximal biliary strictures and perihilar cholangiocarcinoma

Background: The aim of this study was to evaluate potential risk factors associated with benign lesions and perihilar cholangiocarcinoma (PHC) in patients presenting with proximal biliary strictures (PBS). Methods: Patients with PBS who were referred to a specialist HPB centre between 2008 and 2016 were identified. Patients with primary sclerosing cholangitis, metastatic PHC or hilar obstruction by a peripheral tumour were excluded. The final diagnosis was determined either by (1) resection histology or (2) combination of biopsy and clinical course. Multivariable analysis of clinical, laboratory and radiological data was undertaken to identify independent predictors of benign and malignant lesions. Results: 155 consecutive patients were identified, including 25 patients (16%) with benign PBS. Abdominal pain (odds ratio [OR] 3.36; p = 0.027), serum CA19.9 < 100 U/ml (OR 10.35; p = 0.001), and absence of mass on imaging (OR 4.66; p = 0.004) were all associated with the presence of benign lesions on multivariable analysis. Conclusions: This study has identified several independent variables that may differentiate between benign and malignant proximal biliary strictures. A larger multi-institutional study would be warranted to validate these findings, and to develop a risk score to stratify patients with suspected PHC.