Conditional survival in patients with unresectable perihilar cholangiocarcinoma

Background: Conditional survival is the life expectancy from a point in time for a patient who has survived a specific period after presentation. The aim of the study was to estimate conditional survival for patients with unresectable perihilar cholangiocarcinoma. Methods: Patients with unresectable perihilar cholangiocarcinoma from two academic hospitals in the Netherlands between 2002 and 2012 were assessed. A multivariable Cox proportional hazards analysis was performed to identify risk factors associated with overall survival. Survival was estimated using the Kaplan-Meier method to evaluate factors associated with overall survival. Results: In total, 572 patients were included. Overall survival was 42% at one year and 6% at three years. The conditional chance of surviving three years was 15% at 1 year and increased to 38% at 2 years. Independent poor prognostic factors for overall survival were age >= 65 years, tumor size >3 cm on imaging, bilirubin levels (> 250 mmol/L), CA19-9 level at presentation (> 1000 U/ml), and suspected distant metastases on imaging. The conditional survival of patients with and without these prognostic factors was comparable after patients survived the first two or more years. Conclusion: The conditional chance of surviving for patients with unresectable perihilar cholangiocarcinoma increases with time. Poor prognostic factors become less relevant once patients have survived two years.