The predictive value of PD-L1 expression in patients with advanced hepatocellular carcinoma treated with PD-1/PD-L1 inhibitors: A systematic review and meta-analysis

Background and Aim: Programmed death 1 (PD-1) and programmed death ligand 1 (PD-L1) inhibitors have transformed the treatment landscape of advanced hepatocellular carcinoma (HCC), but consistent responses are not observed in all patients, and prognostic biomarkers to guide treatment decisions are lacking. We aimed to evaluate the predictive value of PD-L1 expression in advanced HCC patients treated with PD-1/PD-L1 inhibitors.Methods: A comprehensive search of PubMed, Embase, Web of Science, and the Cochrane Library was conducted. Studies comparing the objective response rate (ORR) and/or disease control rate (DCR) based on the tumor PD-L1 status of HCC were included.Results: Eleven studies with 1,330 HCC patients treated with PD-1/PD-L1 inhibitors were included. Pooled odds ratio (OR) analysis demonstrated a significantly improved ORR in PD-L1-positive patients compared with PD-L1-negative patients (OR, 1.86, 95% CI, 1.35-2.55). Similar results were observed in the anti-PD-1 treatment (p < 0.001) and anti-PD-1/PD-L1 monotherapy (p < 0.001) subgroups. The pooled ORRs in the PD-L1-positive and PD-L1-negative groups were 26% (95% CI, 20%-32%) and 18% (95% CI, 13%-22%), respectively. For DCR, the pooled OR analysis showed no significant difference between PD-L1-positive patients and PD-L1-negative patients (66% [95% CI, 55%-76%] vs. 69% [95% CI, 62%-76%]; OR, 0.92, 95% CI, 0.59-1.44). The results were consistent across the drug target and combination treatment subgroups.Conclusion: Positive PD-L1 expression is associated with a better ORR in advanced HCC patients treated with anti-PD-1/PD-L1-based therapies. This feature can help to identify HCC patients who will benefit most from PD-1/PD-L1 inhibitors.