A New Clinically Based Staging System for Perihilar Cholangiocarcinoma

OBJECTIVES: Current staging systems for perihilar cholangiocarcinoma (pCCA) are inadequate, as they are based on surgical pathology and therefore not relevant to unresectable patients. Clinical trials for potential targeted therapies for pCCA are hampered by the lack of an accurate, nonoperative staging system for predicting survival. We aimed at developing a clinical staging system for pCCA, which would be of prognostic relevance for all pCCA patients and help stratify patients for clinical trials. METHODS: Clinical information at the time of pCCA diagnosis of 413 patients seen at Mayo Clinic, Rochester, MN between 2002 and 2010 was retrospectively analyzed. A survival predictive model was developed using Cox proportional hazards analysis. The performance of the staging system was compared with the current AJCC/UICC (the American Joint Committee on Cancer/the Union for International Cancer Control) 7th tumor-node-metastasis (TNM) staging system. RESULTS: Eastern Cooperative Oncology Group (ECOG) status, tumor size and number, vascular encasement, lymph node and peritoneal metastasis and CA 19-9 level were grouped into a four-tier staging system. The median survivals of stages I, II, III, and IV patients were 48.6, 21.8, 8.6, and 2.8 months, with hazard ratios (95% confidence interval) of 1.0 (reference), 1.7 (1.1-2.6), 3.1 (2.0-4.7), and 8.7 (5.2-14.5), respectively (P < 0.0001). This staging system had greater concordance statistics (standard error) than the TNM staging system (0.725 (0.018) vs. 0.614 (0.017)), indicating better performance in predicting survival. CONCLUSIONS: This staging system, based on nonoperative information at the time of pCCA diagnosis, has excellent discriminatory power to classify patients into four prognostic stages. It could be useful to clinicians and for the design of clinical trials.