Adjuvant chemotherapy for intrahepatic cholangiocarcinoma: approaching clinical practice consensus?

Background: Intrahepatic cholangiocarcinoma (ICC) is rare with limited evidence-based guidelines. This retrospective study evaluates the use of chemotherapy in patients with resected ICC. Methods: The Surveillance Epidemiology and End Results (SEER) program database was used to identify patients with resected ICC. Patients were stratified by date of diagnosis (2000-2004, 2005-2009, 2010-2014), T, and N stage. Multivariable logistic regression models identified predictors of chemotherapy use. Kaplan-Meier and Cox proportional hazard models were used to identify survival trends. Results: One thousand and two hundred twenty-three patients met inclusion criteria. Chemotherapy utilization increased over time (33% to 41%, P <= 0.05). Chemotherapy use increased in lymph node (LN) positive patients [32% to 60% in 2010-2014; (P <= 0.05) and T3/T4 disease (40% to 60% in 2010-2014; P <= 0.01], but not in patients with LN negative or T1/T2 disease. LN positivity was associated with utilization of chemotherapy in 2005-2009 and 2010-2014. Overall survival increased from 32 to 41 months (P <= 0.05). In LN positive patients, chemotherapy was associated with a decreased hazard ratio of death (P <= 0.05) and T3/ T4 disease was associated with an increased hazard ratio of death (P <= 0.05). Conclusions: Adjuvant chemotherapy use in ICC has increased. More LN positive or patients with T3/T4 tumors are receiving chemotherapy, which may explain the improvement in overall survival.