Clinical outcomes of systemic therapy in patients with unresectable or metastatic combined hepatocellular-cholangiocarcinoma

Background & Aims: The optimal systemic chemotherapy for combined hepatocellular-cholangiocarcinoma (cHCC-CCA) has not yet been defined. The definition and classification of cHCC-CCA has changed recently in the 5th edition of WHO classification. We reviewed the pathological findings with the new classification and analysed the efficacy of systemic chemotherapy in patients with unresectable/metastatic cHCC-CCA. Methods: Among 254 patients with histologically confirmed cHCC-CCA from 1999 to 2015 in Asan Medical Center, Seoul, Korea, 99 patients who received systemic chemotherapy for unresectable/metastatic disease were included. Overall response rate (ORR), progression-free survival (PFS) and overall survival (OS) were retrospectively evaluated. Results: Sorafenib (n = 62) and cytotoxic chemotherapy (n = 37) were administered as first-line chemotherapies; the ORR was 14.1%, and the median PFS and OS were 3.8 and 10.6 months, respectively, with a median follow-up duration of 39.6 months. The efficacy outcomes were not significantly different between patients who received sorafenib and those who received cytotoxic chemotherapy (ORR, 9.7% vs 21.6%, P =.14; median PFS, 4.2 vs 2.9 months, P =.52; median OS, 10.7 vs 10.6 months, P =.34). In multivariate analysis, large intrahepatic tumour burden (≥30% of liver volume), elevated serum bilirubin and non-platinum containing first-line chemotherapy remained as significant prognostic factors for poorer OS. Conclusions: The efficacy outcomes according to first-line treatment were not significantly different between sorafenib and cytotoxic chemotherapy, and pathological findings were not found to help for determining appropriate therapeutic agent or assessing the prognosis. To overcome the poor treatment outcomes, further studies are needed to find proper treatment targets, biomarkers and the best treatment strategies.