PerihilarCholangiocarcinoma (pCCA) is located above the opening of the left and right hepatic ducts to the bile cystic duct and accounts for more than 50% of all types of bile duct cancer. The current treatments for pCCA are uncertain and new treatments are urgently needed. The three current clinical staging methods for pCCA, Bismuth-Corlette staging, MKSCC staging and TNM staging, are all based on surgical pathology and cannot be applied to non-surgical or inoperable patients. The lack of accurate non-surgical staging methods makes it impossible to effectively determine the prognosis of patients and to conduct clinical trials of new treatments. To address this issue, Professor Chaiteerakij et al. from the Mayo Clinic proposed a novel staging method for pCCA, which was published in a recent issue of AJG. The team first retrospectively analyzed the medical history data of 413 patients diagnosed with pCCA at the Mayo Clinic from 2002-2010. Exclusion criteria included: oncology-related treatment prior to coming to Mayo (except for biliary stents); incomplete imaging data; and refusal to participate. All patients were evaluated for resectability of the tumor and, if available, liver transplantation; otherwise, systemic chemotherapy or best supportive care (BSC) was administered. For jaundiced patients with unresectable tumors, palliative biliary drainage was performed. Then, Prof. Chaiteerakij divided the patients into four groups according to treatment: transplantation group, resection group, palliative drainage group, and BSC group. The new staging method was applied to each group of patients separately and then compared with the current 7th edition TNM staging method. The analysis revealed that the TNM staging method had poor discriminatory ability, and when patients were grouped by treatment, the TNM staging method was only correlated with survival in the transplantation group and poorly correlated with the other groups. In contrast, the consistency score (standard error) of the novel staging method was significantly better than that of the TNM staging method. In conclusion, this novel staging method takes into account both patient factors and tumor characteristics, obtains information on all variables at the time of initial diagnosis and before surgery, and does not rely on pathological examination. It also has a good ability to differentiate the survival of patients with each staging and can better infer the prognosis than the current TNM staging method. However, the subjects of this study were all Western population, and primary sclerosing cholangitis was the main cause of pCCA in this population. Therefore, further validation of whether this staging method can be used in other populations is needed.