Exploring tumor microenvironment in patients with advanced hepatocellular carcinoma using needle biopsy samples Young Award

Background and Aims: Immune checkpoint inhibitors and combination of those and other agents have been available in advanced hepatocellular carcinoma (HCC). Although exploring tumor microenvironment (TME) has essential clinical implications, most of the studies on TME in HCC are based on the analysis of archive samples at the time of diagnosis as HCC. Considering a lengthy clinical course, TME at the time of diagnosis may differ from that at the time of systemic therapy indication. The present study was aimed to analyze TME by using needle biopsy samples obtained prior to initiation of systemic therapy in patients with advanced HCC. Methods: HCC was confirmed via pathological examination in 70 patients and their samples were analyzed. TME was evaluated by PD-L1, CD8, VEGF, and HLA-class1 immunohistochemical analyses. Results: 1) PD-L1⁺tumor was not dominant (28.6%). PD-L1⁺expression correlated with high infiltration of CD8⁺lymphocytes. 2) PD-L1⁺expression was associated with high AFP levels in advanced HCC. Advanced HCC patients with macro vascular invasion indicated high infiltration of CD8⁺lymphocytes. 3) Of the 70 patients, 20 patients were able to analyze archive samples. 20.0% had a change in PD-L1 expression to positive, and 35.0% had a change in infiltration of CD8⁺lymphocytes to high. Conclusions: Assessments of TME should be conducted using fresh biopsy samples before starting immunotherapy for the prediction of effectiveness or the treatment selection.