Associations between plasma cytokine levels and gut microbiota composition in metastatic renal cell carcinoma (mRCC).

Abstract

351 Background: Plasma cytokines and the gut microbiome have been shown separately to influence the response to systemic therapy in mRCC. We sought associations between serum cytokines and gut microbial composition in patients (pts) with mRCC. Methods: Eligibility requirements included histologically proven mRCC and an intent to receive either vascular endothelial growth factor-tyrosine kinase inhibitor (VEGF-TKI) or immune checkpoint inhibitor (ICI). Blood samples were collected prior to treatment initiation and immunologic profiles were evaluated using a Human Cytokine 30-plex protein assay (Invitrogen). Stool was collected at baseline and shotgun metagenomic sequencing was performed to quantify gut microbial populations using previously published methods (Salgia et al Eur Urol 2020). Results: A total of 50 pts were studied (36:14 M:F) with a median age of 67 (range, 32-85). Twenty pts and 30 pts had subsequent initiation of VEGF-TKI and ICI therapy, respectively. Levels of Akkermansia spp were significantly higher in pts who were IL-6 low (P = 0.023). In contrast, pts who were IL-6 high had higher levels of enteric pathogens, including Salmonella spp and Enterococcus spp. Both Akkermansia spp and Bacteroides spp levels were higher in pts who were IL-8 low. Associations between cytokine levels, microbiome composition, and treatment response will be presented. Conclusions: Given studies suggesting the role of Akkermansia spp in enhancing ICI response (Routy et al Science 2018), our data provide a critical link between the gut microbiome and systemic immunomodulation.