Personalized Medicine and Imaging Stool Bacteriomic Profiling in Patients with Metastatic Renal Cell Carcinoma Receiving Vascular Endothelial Growth Factor–Tyrosine Kinase Inhibitors

Purpose: Diarrhea occurs in approximately half of patients with metastatic renal cell carcinoma (mRCC) receiving vascular endothelial growth factor–tyrosine kinase inhibitors (VEGF-TKI). We evaluated the relationship between VEGF-TKI–related diarrhea and stool microbiota. Experimental Design: Stool samples were collected from 20 mRCC patients receiving VEGF-TKIs. 16S rRNA sequencing was used to characterize the stool bacteriomic profiling of patients. Assay validation with Salmonella typhimurium spike-in experiments suggested greatest speciation with use of the V5 region. Results: Higher levels of Bacteroides spp. and lower levels of Prevotella spp. were found in patients with diarrhea. In addition, patients receiving VEGF-TKIs with mRCC appeared to have less relative abundance of Bifidobacterium spp. as compared with previous reports based on healthy subjects. Conclusions: We have thus demonstrated interplay between microbiota and VEGF-TKI–induced diarrhea. Further studies are warranted to evaluate the potential causative role of preexisting dysbiosis in VEGF-TKI–related diarrhea. Clin Cancer Res; 1–8. 2015