Expression pattern of PD‐1/PD‐L1 in primary liver cancer with clinical correlation

Abstract Immunotherapy, including ICIs, has emerged as an invaluable treatment option for advanced PLC. Nevertheless, the expression patterns of PD‐L1 and PD‐1 in PLC remain incompletely understood. In this study, the expression pattern and clinical correlation of PD‐L1 and PD‐1 were analysed in 5245 PLC patients. The positivity rates of PD‐L1 and PD‐1 were very low in the patient PLCs, but the positivity rates of PD‐L1 and PD‐1 were higher in the ICC and cHCC‐ICC than in HCC. The expression of PD‐L1 and PD‐1 correlated with the malignant phenotypes and clinicopathological characteristics of PLC. Interestingly, PD‐1 positivity might serve as an independent prognostic factor. Based on a systematic analysis of a large amount of PLC tissues, we proposed a novel classification of PD‐1/PD‐L1 expression in HCC and ICC. In light of this stratification, we observed a close correlation between PD‐L1 levels and PD‐1 expression in HCC and ICC.