Outcome and validation of a new clinically based staging system for predicting survival of perihilar cholangiocarcinoma patients

BACKGROUND AND AIM: Currently available staging systems for cholangiocarcinoma (CCA) are not applicable to patients with unresectable stage. A new clinical staging system for perihilar CCA (pCCA) subtype has been recently developed in a US cohort, with a good performance in predicting survival of all pCCA patients. We aimed to determine outcomes of pCCA patients and evaluate predictive performance of this staging system in an Asian population. METHODS: All 141 patients diagnosed with pCCA between 2003 and 2012 were identified. Clinical information was retrospectively abstracted. Patients were classified into four stages based on the new staging system. Survival predictors were analyzed using the Cox proportional hazard analysis. RESULTS: Of the 141 pCCA patients, 38 (27%), 101 (72%), and 2 (1%) received resection, palliative biliary drainage ± chemotherapy, and best supportive care, respectively. Survival predictors included resectable disease, tumor size, distant metastasis, and cancer antigen 19‐9 ≥ 1000 U/mL. When classified by clinical stages, 13, 4, 99, and 25 patients were in stages I, II, III, and IV, with median survivals of 18.4, 7.3, 6.3, and 2.6 months; and hazard ratio (95% confidence interval) of 1.0 (reference), 1.7 (0.5–5.5), 3.2 (1.5–6.7), and 10.8 (4.6–25.0), respectively. CONCLUSION: The clinical staging system has a limited performance in differentiating stage II pCCA patients from stage III patients in the Thai cohort. This can be due to differences in patient characteristics and treatment modalities between the Asian and White pCCA populations. However, the median survivals of patients with other stages are significantly different.