Microenvironment characterization and multi-omics signatures related to prognosis and immunotherapy response of hepatocellular carcinoma

BACKGROUND

Immune cell infiltration in the tumor microenvironment (TME) affects tumor initiation, patients' prognosis and immunotherapy strategies. However, their roles and interactions with genomics and molecular processes in hepatocellular carcinoma (HCC) still have not been systematically evaluated.

METHODS

We performed unsupervised clustering of total 1000 HCC samples including discovery and validation group from available public datasets. Immune heterogeneity of each subtype was explored by multi-dimension analysis. And a support vector machine (SVM) model based on multi-omics signatures was trained and tested. Finally, we performed immunohistochemistry to verify the immune role of signatures.

RESULTS

We defined three immune subtypes in HCC, with diverse clinical, molecular, and genomic characteristics. Cluster1 had worse prognosis, better anti-tumor characteristics and highest immune scores, but also accompanied by immunosuppression and T cell dysfunction. Meanwhile, a better anti-PD1/CTLA4 immunotherapeutic response was predicted in cluster1. Cluster2 was enriched in TAM-M2 and stromal cells, indicating immunosuppression. Cluster3, with better prognosis, had lowest CD8 T cell but highest immune resting cells. Further, based on genomic signatures, we developed an SVM classifier to identify the patient's immunological status, which was divided into Type A and Type B, in which Type A had poorer prognosis, higher T cell dysfunction despite higher T cell infiltration, and had better immunotherapeutic response. At the same time, MMP9 may be a potential predictor of the immune characteristics and immunotherapeutic response in HCC.

CONCLUSIONS

Our work demonstrated 3 immune clusters with different features. More importantly, multi-omics signatures, such as MMP9 was identified based on three clusters to help us recognize patients with different prognosis and responses to immunotherapy in HCC. This study could further reveal the immune status of HCC and provide potential predictors for immune checkpoint treatment response.

Overshadowed prospect of programmed cell death protein-1 (PD-1) inhibitor as monotherapy for patients with advanced hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a prevalent and refractory cancer in the world and very few drugs are available for the disease treatment currently. Programmed cell death protein-1 (PD-1) monoclonal antibodies including nivolumab and pembrolizumab has received accelerated approval for treatment of advanced HCC based on phase 1/2 clinical trials. However, the recently disclosed results of phase 3 clinical trials showed that both nivolumab and pembrolizumab as monotherapy failed to meet the primary objectives, which might overshadow the prospect of PD-1 inhibitors as monotherapy in treatment of advanced and unresectable HCC. The feasibility of PD-1 inhibitors in combination with other therapies or in other HCC settings requires further verification in the future.

The treatment of intermediate stage tumours beyond TACE: From surgery to systemic therapy

Treatment of hepatocellular carcinoma (HCC) is dependent on the stage of the disease. Intermediate stage HCC encompasses the largest subgroup of patients with the disease, and is characterized by substantial heterogeneity. The standard therapeutic approach, transarterial chemoembolization (TACE), is probably over-used and may not be appropriate for all patients with intermediate stage HCC. In patients with extensive tumour bulk, multi-nodular spread or impaired liver function, TACE may not be optimal and other treatments can be considered as a first-line treatment. These include surgery, percutaneous ablation, radioembolization or systemic treatment. In addition, patients who do not achieve complete or partial necrosis (TACE failure) and patients with early recurrence after TACE, should be managed individually, considering systemic treatments usually reserved for advanced disease. In selected cases and in patients who achieve downstaging, radical approaches such as hepatic resection or even liver transplantation can be considered. In this review, we evaluate the current literature for the treatment strategies for patients with intermediate Barcelona Clinic Liver Cancer (BCLC) B stage HCC.