Abstract
African-American (AA) men have a 1.5-fold higher incidence of prostate cancer (PCa) than non-Latino White (WH) men and are nearly 2.5 times more likely to die from their disease. These disparities are likely due to a combination of social, environmental, and biological factors. Discerning the biological determinants of aggressive PCa in AA men remains a critical and unmet need in cancer health disparities research. Although there have been several large-scale genome sequencing studies that identified unique molecular drivers in primary and metastatic PCa, these have included few AA patients, even fewer with potentially lethal PCa, and have generally lacked clinical outcome data. Work by our group and others demonstrates that the most common somatic genomic alterations in primary PCa (such as ERG rearrangement and PTEN deletion) occur at significantly different frequencies in AA and WH men, providing the first direct evidence for molecular differences between PCa arising in AA and WH patients. Similarly, gene expression studies by other groups have consistently found that various immune response pathways are more highly expressed in PCa arising in AA compared to WH patients. However to date, few studies have integrated somatic molecular subtype data with immune tumor microenvironment (TME) characterization across different populations. To begin to address these knowledge gaps, we have studied primary PCa tissues from a unique cohort comprising 200 self-identified AA and 200 WH patients, matched by grade and other clinical-pathologic parameters, with long-term follow-up for biochemical recurrence and metastasis. This cohort is unique in that it is highly enriched for high-risk disease and has now been profiled for somatic genomic, epigenomic, transcriptomic and tumor microenvironment landscapes, enabling one of the first integrative molecular portraits of AA PCa. We find that tumor infiltrating T-lymphocyte density is significantly correlated with underlying tumor molecular subtype and oncologic outcomes, but does not vary by racial ancestry. In contrast, using a combination of transcriptomic, methylation and quantitative immunohistochemical analyses, we demonstrate that tumor infiltrating B-lymphocyte density is significantly higher among AA compared to WH PCa patients, irrespective of molecular subtype, and trends towards improved outcomes.
Citation Format: Tamara L. Lotan. The immunogenomic landscape of primary prostate cancer in African-American men [abstract]. In: Proceedings of the AACR Virtual Conference: Thirteenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2020 Oct 2-4. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(12 Suppl):Abstract nr IA33.
RSS Feeds