Clinical characteristics and outcome of patients with combined hepatocellular-cholangiocarcinoma-a European multicenter cohort

BACKGROUND

There is no clear consensus on the optimal systemic treatment regimen in combined hepatocellular-cholangiocarcinoma (cHCC-CCA) patients. We describe clinical characteristics and outcome of cHCC-CCA patients, with a special focus on patients receiving palliative systemic therapy, including immune checkpoint inhibitors (ICIs).

METHODS

In this European retrospective, multicenter study, patients with histologically proven cHCC-CCA treated at four institutions between April 2003 and June 2022 were included. In patients receiving palliative systemic therapy, outcome was compared between cytotoxic chemotherapy (CHT)- and non-cytotoxic CHT (nCHT)-treated patients.

RESULTS

Of 101 patients, the majority were male (n = 70, 69%) with a mean age of 64.6 ± 10.6 years. Only type of first-line treatment was independently associated with overall survival (OS). Palliative systemic therapy was administered to 44 (44%) patients. Of those, 25 (57%) patients received CHT and 19 (43%) had nCHT (n = 16 of them sorafenib) in systemic first line. Although there was no significant difference in overall response rate (ORR; CHT versus nCHT: 8% versus 5%), disease control rate (24% versus 21%), and median progression-free survival {3.0 months [95% confidence interval (CI) 1.4-4.6 months] versus 3.2 months (95% CI 2.8-3.6 months), P = 0.725}, there was a trend towards longer median OS in the CHT group [15.5 months (95% CI 8.0-23.0 months) versus 5.3 months (95% CI 0-12.5 months), P = 0.052]. However, in multivariable analysis, type of first-line regimen (CHT versus sorafenib) was not associated with OS. ORR in patients receiving ICIs (n = 7) was 29%.

CONCLUSIONS

In patients with cHCC-CCA, OS, progression-free survival, ORR, and disease control rate were not significantly different between individuals receiving CHT and patients receiving nCHT. Immunotherapy may be effective in a subset of patients. Prospective studies are needed to identify optimal systemic treatment regimens in cHCC-CCA.

Genomic profiling of combined hepatocellular-cholangiocarcinoma reveals similar genetics to hepatocellular carcinoma

Combined hepatocellular-cholangiocarcinomas (CHC) are mixed tumours with both hepatocellular carcinoma (HCC) and cholangiocarcinoma (CC) components. CHC prognosis is similar to intrahepatic CC (ICC) and worse than HCC; staging and treatment generally follow ICC algorithms. However, the molecular biology of CHC remains poorly characterised. We performed capture-based next-generation sequencing of 20 CHC and, for comparison, 10 ICC arising in cirrhosis. Intratumour heterogeneity was assessed by separately sequencing the HCC and CC components of nine CHC. CHC demonstrated molecular profiles similar to HCC, even in the CC component. CHC harboured recurrent alterations in TERT (80%), TP53 (80%), cell cycle genes (40%; CCND1, CCNE1, CDKN2A), receptor tyrosine kinase/Ras/PI3-kinase pathway genes (55%; MET, ERBB2, KRAS, PTEN), chromatin regulators (20%; ARID1A, ARID2) and Wnt pathway genes (20%; CTNNB1, AXIN, APC). No CHC had alterations in IDH1, IDH2, FGFR2 or BAP1, genes typically mutated in ICC. TERT promoter mutations were consistently identified in both HCC and CC components, supporting TERT alteration as an early event in CHC evolution. TP53 mutations were present in both components in slightly over half the TP53-altered cases. By contrast, focal amplifications of CCND1, MET and ERRB2, as well as Wnt pathway alterations, were most often exclusive to one component, suggesting that these are late events in CHC evolution. ICC in cirrhosis demonstrated alterations similar to ICC in non-cirrhotic liver, including in IDH1 or IDH2 (30%), CDKN2A (40%), FGFR2 (20%), PBRM1 (20%), ARID1A (10%) and BAP1 (10%). TERT promoter and TP53 mutation were present in only one ICC each. Our data demonstrate that CHC genetics are distinct from ICC (even in cirrhosis) and similar to HCC, which has diagnostic utility and implications for treatment. Copyright © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.