Background: Cancer immunotherapy is being developed as a promising alternative for advanced non-small cell lung cancer (NSCLC). However, novel biomarkers are required to select patients that will benefit from treatment with immune checkpoint inhibitors (ICIs) for a long period of time. The gut microbiome is expected to be a promising biomarker of ICI response owing to the regulation of the immune status within the host.
Methods: In this retrospective study, we included 17 Japanese patients with advanced NSCLC who were treated with ICIs for >3 months in our hospital. Fecal samples obtained from the patients during ICI treatment were analyzed by 16S ribosomal RNA gene sequencing. We examined the correlation between the diversity of the gut microbiome and treatment with ICIs.
Results: Several bacterial species were more abundant in ICI responders than in non-responders. Patients with abundant Lactobacillus and Clostridium tended to have a longer time to treatment failure (TTF) after receiving ICI than those with a lower abundance.
Conclusions: In conclusion, the composition of the gut microbiome is associated with better clinical benefits from ICI treatment in Japanese patients with NSCLC. A further large-scale study is warranted to validate the composition of the gut microbiome as a novel clinical factor influencing the response to ICIs for an extended time in NSCLC.
Keywords: Immunotherapy; gut microbiome; non-small cell lung cancer (NSCLC); retrospective analysis.
2019 Translational Lung Cancer Research. All rights reserved.