Effect of liver fibrosis on survival in patients with intrahepatic cholangiocarcinoma: A SEER population-based study

Background: Intrahepatic cholangiocarcinoma (iCCA) is a biliary tract malignancy with rising incidence in recent decades. While the causative role of cirrhosis in the development of iCCA is well established, the role of cirrhosis as a prognostic factor in iCCA is debatable. Materials and Methods: The study population consisted of 512 patients diagnosed with iCCA between 2004-2016 collected from the Surveillance, Epidemiology and End Results (SEER) database. The impact of fibrosis on overall and cancer-specific survival 12, 36 and 60 months following diagnosis, was evaluated in the entire cohort and in sub-groups stratified according to treatment approach and the American Joint Committee on Cancer (AJCC) tumor stage using a Cox proportional-hazards model. Results: After adjusting for age, sex, race, year of diagnosis, AJCC stage, and surgical treatment strategy, advanced fibrosis was associated with worse cancer-specific survival across follow up periods (HR 1.49 (1.13-1.96, p = 0.005); HR 1.44 (1.14-1.83, p = 0.002) and HR 1.45 (1.15-1.83, p = 0.002) for 12, 36 and 60 months, respectively). Similar effects were observed for overall survival. Among patients that underwent surgical resection, advanced fibrosis was associated with worse overall survival and cancer-specific survival across follow up periods. Fibrosis was associated with worse overall and cancer-specific survival in patients with a later stage (III-IV) at diagnosis but this effect was not demonstrated in early stages. Conclusions: Patients with iCCA and advanced liver fibrosis have an increased risk of both overall and cancer-specific mortality compared to patients with earlier stages of fibrosis.