The effect of PD-L1/PD-1 immunotherapy in the treatment of squamous non-small-cell lung cancer: a meta-analysis of randomized controlled clinical trials

BACKGROUND: This meta-analysis evaluated the efficacy of PD-L1/PD-1 immunotherapy compared with chemotherapy in IIIB or IV or recurrent squamous non-small cell lung cancer (NSCLC) patients. METHODS: We performed a literature search on the PubMed, EMBASE, Web of Science, and Cochrane databases, in addition to the abstracts from major conference proceedings of the European Society for Medical Oncology (ESMO), the American Society of Clinical Oncology (ASCO), and the World Conference on Lung Cancer (WCLC) from 2004 to May 2019. Randomized controlled trials that compared PD-L1/PD-1 immunotherapy with chemotherapy in IIIB or IV or recurrent squamous NSCLC were included. The endpoints were overall survival (OS), progression-free survival (PFS), objective response rate (ORR), disease control rate (DCR), 1-y OS rate, and 1-y PFS rate. RESULTS: A total of 3,213 IIIB or IV or recurrent squamous NSCLC patients from 12 trials of high quality were included in this meta-analysis, among whom 1,677 were in the PD-L1/PD-1 immunotherapy group and 1,536 were in the chemotherapy group. The results indicated that compared with chemotherapy, immunotherapy significantly prolonged OS (HR =0.75; 95% CI, 0.68–0.83; P