Abstract
Background: Immune-checkpoint inhibitors (ICIs) have been approved as 1st line therapy and benefit patients with advanced cancer. However, still many patients fail to achieve the significant efficacy, a predictor for precise patient selection is needed. The aim of our study is to determine whether the administration of antibiotics before or at the beginning of ICIs treatment is a prognostic factor of progression-free survival (PFS) and overall survival (OS) in patients with advanced cancer.Methods: A systematic search in PubMed, Embase, Cochrane and Web of Science databases was conducted using the search terms antibiotic, PD-1, PD-L1, CTLA-4, combined with cancer, tumor, neoplasm, or carcinoma. Data extraction was performed independently. Hazard ratio (HR) for PFS and OS of antibiotics (+) group vs antibiotics (-) group were pooled according to random or fixed-effects models. HRs with 95% confidence intervals (CIs) for PFS and OS were pooled to obtain prognostic information and aggregate values.Results: Nine studies including 1163 patients were included in this meta-analysis. By PFS analysis, antibiotics administration was associated with a significantly increased risk of disease progression (HR, 1.76; 95% CI, 1.37-2.26; P< 0.01). By OS analysis, antibiotics uptake also showed an HR in favor of death (HR, 1.7; 95% CI, 1.40-2.07; P< 0.01).Conclusions: Based on the existing evidence, antibiotics administration is a prognostic factor for reduced PFS and OS in patients receiving ICIs treatment. The time interval between antibiotics administration and ICIs treatment should be considered.