Race as a Contributor to Stromal Modulation of Tumor Progression

SIMPLE SUMMARY: When compared to European Americans (EA), the African American (AA) population is at a higher risk of developing various forms of cancers and is more vulnerable to cancer-related death. To overcome these disparities and develop personalized treatment strategies, it is important to understand the factors contributing to tumor progression and aggressiveness in AA patients. The tumor microenvironment (TME) contains various cellular and non-cellular components known to play an important role in tumor growth and progression. Recent studies indicate racial differences in gene expression within the TME. In this review, we focus on such differences in various cancers and discuss the relevance of this TME diversity in the acquisition of aggressive forms of disease and poorer response to therapy in AA patients. In general, AA patients appear to host a more immune suppressive TME, suggesting the potential utility of targeting this aspect of tumor biology. ABSTRACT: Stromal cells play crucial roles in tumor development and are increasingly attractive targets for therapy. There are considerable racial disparities in the incidence and progression of many tumors, reflecting both environmental exposure and genetic differences existing between races. Tumorigenesis and tumor progression are linked to both the propensity to suffer an initiating event and the host response to such an event once it occurs, contributing to incidence and outcomes. In this review, we focused on racial disparities in the tumor microenvironment (TME) of different cancers as potential modulators of growth, metastasis, and response to treatment. Several studies suggest that the TME in AA has a distinct tumor biology and may facilitate both early onset and aggressive tumor growth while inhibiting anti-tumorigenic properties. The TME of AA patients often exhibits an immunosuppressive microenvironment with a substantial enrichment of immune inflammatory pathways and genes. As a result, AA patients can potentially benefit more from treatment strategies that modulate the immune system. Focusing on TME components for diagnostic and therapeutic purposes to address racial disparities is a promising area of investigation. Future basic and clinical research studies on personalized cancer diagnosis and treatment should acknowledge the significance of TME in racial disparities.