Engaging stimulatory immune checkpoint interactions in the tumour immune microenvironment of primary liver cancers - how to push the gas after having released the brake.

Hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA) are the first and second most common primary liver cancer (PLC). For decades, systemic therapies consisting of tyrosine kinase inhibitors (TKIs) or chemotherapy have formed the cornerstone of treating advanced-stage HCC and CCA, respectively. More recently, immunotherapy using immune checkpoint inhibition (ICI) has shown anti-tumour reactivity in some patients. The combination regimen of anti-PD-L1 and anti-VEGF antibodies has been approved as new first-line treatment of advanced-stage HCC. Furthermore, gemcibatine plus cisplatin (GEMCIS) with an anti-PD-L1 antibody is awaiting global approval for the treatment of advanced-stage CCA. As effective anti-tumour reactivity using ICI is achieved in a minor subset of both HCC and CCA patients only, alternative immune strategies to sensitise the tumour microenvironment of PLC are waited for. Here we discuss immune checkpoint stimulation (ICS) as additional tool to enhance anti-tumour reactivity. Up-to-date information on the clinical application of ICS in onco-immunology is provided. This review provides a rationale of the application of next-generation ICS either alone or in combination regimen to potentially enhance anti-tumour reactivity in PLC patients.

Cryptogenic non-cirrhotic HCC: Clinical, prognostic and immunologic aspects of an emerging HCC etiology.

The incidence of hepatocellular carcinoma (HCC) in non-cirrhotic livers is rising significantly, but clear risk factors for screening remain elusive. This study sought to characterize non-cirrhotic HCC etiologies. HCC cases from 2009 to 2020 in a Dutch referral center were examined, revealing 371 out of 1654 cases (22%) as non-cirrhotic. Notably, the incidence of non-cirrhotic HCC increased by 61% in the time frame between 2009 and 2020. Interestingly 39% of non-cirrhotic HCC cases had cryptogenic origins. Cryptogenic non-cirrhotic HCC exhibited similarities with non-cirrhotic NAFLD HCC, but displayed advanced tumor stages, lower surgical rates, and a more frequent presence of symptoms, which substantiated in poor survival rates. Advanced cryptogenic non-cirrhotic HCC stages exhibited elevated serum interleukin-6 levels compared to non-cirrhotic HCC with defined etiologies. Comparative analysis encompassing cryptogenic and NAFLD non-cirrhotic HCC cohorts and controls unveiled comparable circulating immune biomarker profiles and PNPLA3 polymorphisms. To conclude, the primary etiology of non-cirrhotic HCC in our cohort has not defined risk factors. This cryptogenic variant exhibits distinct traits, such as advanced tumors and increased symptoms, and most resemble burned-out NAFLD. Understanding this HCC variant is crucial for improving screening and management strategies.