Genomic differences between black and white patients implicate a distinct immune response to papillary renal cell carcinoma

// David J. Paulucci 1 , John P. Sfakianos 1 , Anders J. Skanderup 2 , Kathleen Kan 1 , Che-Kai Tsao 3 , Matthew D. Galsky 3 , A. Ari Hakimi 4 , Ketan K. Badani 1 1 Department of Urology, Icahn School of Medicine at Mount Sinai Hospital, New York, NY, USA 2 Computational Biology Program, Sloan Kettering Institute for Cancer Research, Memorial Sloan Kettering Cancer Center, New York, NY, USA 3 Department of Medicine, Division of Hematology/Oncology, Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA 4 Department of Surgery—Urology Service, Memorial Sloan Kettering Cancer Center, New York, NY, USA Correspondence to: Ketan K. Badani, email: Ketan.Badani@mountsinai.org Keywords: papillary renal cell carcinoma, racial disparities, immune system signaling, targeted therapy, immune response Received: May 03, 2016     Accepted: November 22, 2016     Published: December 23, 2016 ABSTRACT Significant disparities in survival, incidence and possibly response to current therapies exist between black and white patients with renal cell carcinoma (RCC). Recent genomic evidence to account for these disparities has been reported for clear cell RCC. However, racial disparities at the genomic level for papillary RCC (pRCC) which is a genetically distinct and less responsive histologic subtype of RCC have not been reported. Using The Cancer Genome Atlas (TCGA) data, the present study assessed gene-level expression, somatic mutation and pathway differences between 58 black and 58 white patients with pRCC propensity matched on age, gender and pathologic T stage. Distinct tumor biology with differential expression patterns were observed in black vs. white patients with pRCC. Specifically, significance analysis of microarrays was applied to TCGA gene expression data and identified 163 genes and 120 genes overexpressed in black and white patients, respectively (FDR q<0.05). Gene Set Enrichment Analysis identified 62 gene sets enriched (p<0.10) in blacks. Enrichment of immune immune system pathways were noted in black patients. These included the B cell receptor signaling pathway, the NOD-like receptor signaling pathway and genes involved in defensins. The VEGF pathway was also more significant in black patients. CRYBB2, a gene associated with the WNT pathway was overexpressed in Black patients. While our data requires validation, these findings suggest that race may have implications for distinct immune responses to cancer and that the use of immunotherapies, and VEGFR inhibitors to target these pathways may improve survival in black patients with advanced pRCC.