583 A New Clinically Based Staging System for Intrahepatic Cholangiocarcinoma

BACKGROUND: Currently, the only potentially curative treatment for intrahepatic cholangiocarcinoma (iCCA) is surgical resection. However, only a small proportion of patients with iCCA are diagnosed at a stage of disease early enough to be candidates for resection. Prognostic tools such as the 7th edition of the American Joint Committee of Cancer/International Union Against Cancer staging manual and the several other published staging systems can be used to predict prognosis for resectable iCCA but are not relevant to patients with unresectable disease. We aimed to develop a generalizable prognostic model that can be applied to all patients diagnosed with iCCA.METHODS: Patients with iCCA seen atMayo Clinic, Rochester, MN from 2000 through 2005 were identified (n=259). Demographics and baseline clinical, radiological and laboratory data were abstracted from the electronic medical records. A prognostic model was constructed using Cox proportional hazards analysis with overall survival as the primary endpoint. Patients who were treated with surgery or chemotherapy prior to being seen at Mayo Clinic and patients with missing baseline radiology were excluded from the analysis (n=60). RESULTS: A total of 199 patients with iCCA were included in the analysis. The mean age at diagnosis was 61.1 years (SD=13.5). The cohort comprised of 47.3% females, 7.8% patients with primary sclerosing cholangitis, 0.6% patients with a previous diagnosis of hepatitis C, 0.6% with hepatitis B and 6.1% with cirrhosis. ECOG performance status, involvement of portal vasculature, lesion size, CA19-9 level, bilirubin level and metastasis were included in a 3-level staging system classifying patients into early, intermediate and advanced stages. A total of 165 patients were stratified using our staging system. Hazard ratios (95% Confidence Interval) of death for patients with early, intermediate and advanced stage iCCA were 1.0 (reference), 3.2 (1.9, 5.6), and 5.2 (3.2, 9.3), respectively (P < 0.0001). Median survival for patients with early, intermediate and advanced stage iCCA were 27.5, 9.3, and 5.0 months, respectively. CONCLUSIONS: We have developed a new staging system for iCCA patients based on non-operative clinical variables that classifies patients with iCCA into three distinct stages based on their observed prognosis. This system is potentially useful for stratification of patients enrolled in clinical trials of novel therapies for iCCA. A new clinically based staging system for intrahepatic cholangiocarcinoma