The impact of body mass index on the efficacy of anti-PD-1/PD-L1 antibodies in patients with non-small cell lung cancer

Objectives: : Body mass index (BMI) is reported to be associated with the efficacy of immune checkpoint inhibitors (ICIs) in solid tumors such as melanomas. However, it remains unclear whether such a relationship exists in non-small cell lung cancer (NSCLC) treated with programmed cell death protein 1 (PD-1)/ programmed death-ligand 1(PD-L1) inhibitors. The purpose of this study was to investigate the relationship between BMI and the efficacy of ICI treatment in patients with advanced NSCLC. Materials and methods: : The medical records of NSCLC patients who received PD-1/PD-L1 antibody monotherapy at nine institutions between December 2015 and May 2018 were reviewed retrospectively. The effect of BMI was investigated in two cohorts. Cohort 1 included patients with NSCLCs with high PD-L1 expression (≥ 50 %) treated with pembrolizumab as first-line therapy, and cohort 2 included patients with NSCLCs treated with nivolumab/pembrolizumab/atezolizumab as second- or later-line treatment. Results: : A total of 513 from nine institutions were analyzed (84 in cohort 1, 429 in cohort 2). Using a BMI cut-off value of 22 kg/m2, which is an ideal BMI in our country (high BMI:22.0 and low BMI:22.0), there was no significant difference in the PFS or OS between the high and low BMI patients in cohort 1. However, in cohort 2, survival was significantly longer in patients with a high versus low BMI (PFS: 3.7 vs. 2.8 months, p = 0.036; OS: 15.4 vs. 13.5 months, p = 0.021). Conclusion: : BMI was significantly associated with the efficacy of ICIs in patients with NSCLC treated with second- or later-line PD-1/PD-L1 inhibitors in our cohort.