Shivanshu Awasthi, Anders Berglund, Julieta Abraham-Miranda, Robert J Rounbehler, Kevin Kensler, Amparo Serna, Adriana Vidal, Sungyong You, Michael R Freeman, Elai Davicioni, Yang Liu, R Jeffrey Karnes, Eric A Klein, Robert B Den, Bruce J Trock, Joshua D Campbell, David J Einstein, Raavi Gupta, Steven Balk, Priti Lal, Jong Y Park, John L Cleveland, Timothy R Rebbeck, Stephen J Freedland, Kosj Yamoah
First published: 09 Oct 2020
PMID: 33037017 PMCID: PMC8042600 DOI: 10.1158/1078-0432.CCR-20-2925
Purpose: The role of immune-oncologic mechanisms of racial disparities in prostate cancer remains understudied. Limited research exists to evaluate the molecular underpinnings of immune differences in African American men (AAM) and European American men (EAM) prostate tumor microenvironment (TME).
Experimental design: A total of 1,173 radiation-naïve radical prostatectomy samples with whole transcriptome data from the Decipher GRID registry were used. Transcriptomic expressions of 1,260 immune-specific genes were selected to assess immune-oncologic differences between AAM and EAM prostate tumors. Race-specific differential expression of genes was assessed using a rank test, and intergene correlational matrix and gene set enrichment was used for pathway analysis.
Results: AAM prostate tumors have significant enrichment of major immune-oncologic pathways, including proinflammatory cytokines, IFNα, IFNγ, TNFα signaling, ILs, and epithelial-mesenchymal transition. AAM TME has higher total immune content score (ICSHIGH) compared with 0 (37.8% vs. 21.9%, P = 0.003). AAM tumors also have lower DNA damage repair and are genomically radiosensitive as compared with EAM. IFITM3 (IFN-inducible transmembrane protein 3) was one of the major proinflammatory genes overexpressed in AAM that predicted increased risk of biochemical recurrence selectively for AAM in both discovery [HRAAM = 2.30; 95% confidence interval (CI), 1.21-4.34; P = 0.01] and validation (HRAAM = 2.42; 95% CI, 1.52-3.86; P = 0.0001) but not in EAM.
Conclusions: Prostate tumors of AAM manifest a unique immune repertoire and have significant enrichment of proinflammatory immune pathways that are associated with poorer outcomes. Observed immune-oncologic differences can aid in a genomically adaptive approach to treating prostate cancer in AAM.
©2020 American Association for Cancer Research.
Full text: 10.1158/1078-0432.CCR-20-2925
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