Efficacy of PD-1 or PD-L1 inhibitors and PD-L1 expression status in cancer

摘要

Study question Can patients with cancer who are programmed cell death ligand 1 (PD-L1) negative benefit from programmed cell death 1 (PD-1) or PD-L1 blockade therapy? Methods PubMed, Embase, Cochrane database, and conference abstracts presented at the American Society of Clinical Oncology and European Society of Medical Oncology were searched. Randomised controlled trials of PD-1 or PD-L1 inhibitors (avelumab, atezolizumab, durvalumab, pembrolizumab, and nivolumab) that had hazard ratios for death based on PD-L1 positivity or negativity were included. The threshold for PD-L1 positivity or negativity was that PD-L1 stained cells accounted for 1% of tumour cells, or tumour and immune cells, assayed by an immunohistochemistry staining method.