Luigi Giovanni Lupo

Hepatocellular carcinoma (HCC) is one of most common cancers and the fourth leading cause of death worldwide. Commonly, HCC development occurs in a liver that is severely compromised by chronic injury or inflammation. Liver transplantation, hepatic resection, radiofrequency ablation (RFA), transcatheter arterial chemoembolization (TACE), and targeted therapies based on tyrosine protein kinase inhibitors are the most common treatments. The latter group have been used as the primary choice for a decade. However, tumor microenvironment in HCC is strongly immunosuppressive; thus, new treatment approaches for HCC remain necessary. The great expression of immune checkpoint molecules, such as programmed death-1 (PD-1), cytotoxic T-lymphocyte antigen 4 (CTLA-4), lymphocyte activating gene 3 protein (LAG-3), and mucin domain molecule 3 (TIM-3), on tumor and immune cells and the high levels of immunosuppressive cytokines induce T cell inhibition and represent one of the major mechanisms of HCC immune escape. Recently, immunotherapy based on the use of immune checkpoint inhibitors (ICIs), as single agents or in combination with kinase inhibitors, anti-angiogenic drugs, chemotherapeutic agents, and locoregional therapies, offers great promise in the treatment of HCC. This review summarizes the recent clinical studies, as well as ongoing and upcoming trials.

Biliary tract cancers (BTCs) are characterized by a bad prognosis and the armamentarium of drugs for their treatment is very poor. Although the inflammatory status of biliary tract represents the first step in the cancerogenesis, the microenvironment also plays a key role in the pathogenesis of BTCs, promoting tumor angiogenesis, invasion and metastasis. Several molecules, such as vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF), are involved in the angiogenesis process and their expression on tumor samples has been explored as prognostic marker in both cholangiocarcinoma and gallbladder cancer. Recent studies evaluated the genomic landscape of BTCs and evidenced that aberrations in several genes enrolled in the pro-angiogenic signaling, such as FGF receptor-2 (FGFR-2), are characteristic of BTCs. New drugs targeting the signaling pathways involved in angiogenesis have been tested in preclinical studies both in vitro and in vivo with promising results. Moreover, several clinical studies tested monoclonal antibodies against VEGF and tyrosine kinase inhibitors targeting the VEGF and the MEK/ERK pathways. Herein, we evaluate both the pathogenic mechanisms of BTCs focused on angiogenesis and the preclinical and clinical data available regarding the use of new anti-angiogenic drugs in these malignancies.