Abstract
BACKGROUND: The development of immunotherapy has dramatically changed the treatment of non-small-cell lung cancer. The negative association of antibiotics on the clinical activity of immune checkpoint inhibitors in patients with NSCLC is well known. METHODS: PubMed, Embase, and Medline databases were searched until January 11, 2020. We included retrospective studies of ICIs (e.g., PD-1, PD-L1, and CTLA-4). The clinical outcomes were progression-free survival (PFS) and overall survival (OS). Hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated, and subgroup and sensitivity analyses were performed. RESULTS: Our results indicated that the use of antibiotics reduced the survival of NSCLC patients treated with ICIs. The pooled HRs of PFS and OS were HR = 1.41 (95% CI = 1.23-1.61; P < 0.001) and HR = 2.16 (95% CI = 1.79-2.60; P < 0.001). We divided the studies into 5 subgroups according to antibiotic exposure time. Subgroup analysis showed that the patients that were administered antibiotics [-60 days; 0 days] or [-30 days; 0 days] before the initiation of ICIs treatment had a poorer OS rate, whereas those patients that were administered antibiotics [0 days; 30 days] after the initiation of ICIs treatment had a poorer PFS rate. In summary, ATB treatment in patients [-60 days; +30 days] near the initiation of ICIs treatment significantly reduced the survival in NSCLC patients. CONCLUSION: Our results indicated that ATB use is negatively associated with survival in NSCLC patients treated with ICIs immunotherapy. Similar studies involving a larger sample of cases are still being published. This meta-analysis identified that the timing of ATB treatment in NSCLC patients receiving ICIs immunotherapy has different effects on the OS and PFS of these patients. ATB treatment prior to the initiation of ICIs treatment affects OS, whereas ATB treatment after the initiation of ICIs treatment affects PFS.