Abstract 352P
Background
Immune checkpoint inhibitors (ICI) have been proposed as the standard treatment for different stages of NSCLC in multiple indications. Not all patients benefit, and some even develop immune-related adverse events. It has been postulated that microbiota may play a relevant role in the response to oncological treatment, and this may even be influenced by its metabolites, specifically by short chain fatty acids (SCFA). Butyrate has been proposed as an inhibitor of cancer cell proliferation, with direct antineoplastic effects due to the interactions with histone deacetylase enzymes.
Methods
Prospective, longitudinal, non-interventional, single-centre study. Unresectable stage III or IV non-small cell lung cancer. Candidates to ICI. Stool samples were collected prior to ICI treatment. Samples were collected and managed by the Biobank of Aragón. 16S rDNA massive sequencing was performed on the variable regions V3 and V4 of the 16 rRNA in the Central Translational Genomics Support Unit at the Ramón y Cajal Health Research Institute. A taxonomic analysis was carried out. Alpha and beta-diversity distance between samples was estimated via Linear discriminant analysis Effect Size (LEfSe). SCFA were analyzed by gas chromatography-mass spectroscopy. Descriptive and survival analysis was performed.
Results
N=55 patients (39 men/16 woman). 85%
Conclusions
This was a pioneering study in SCFA analysis.We found no markers related to microbiome composition or SCFAs that could contribute to predicting ICI response or irAE onset.
Funding
Instituto de Salud Carlos III.
Disclosure
All authors have declared no conflicts of interest.