Plasma cells are enriched in localized prostate cancer in Black men and are associated with improved outcomes.

Black men die more often of prostate cancer yet, interestingly, may derive greater survival benefits from immune-based treatment with sipuleucel-T. Since no signatures of immune-responsiveness exist for prostate cancer, we explored race-based immune-profiles to identify vulnerabilities. Here we show in multiple independent cohorts comprised of over 1,300 patient samples annotated with either self-identified race or genetic ancestry, prostate tumors from Black men or men of African ancestry have increases in plasma cell infiltrate and augmented markers of NK cell activity and IgG expression. These findings are associated with improved recurrence-free survival following surgery and nominate plasma cells as drivers of prostate cancer immune-responsiveness. A recent report suggested Black men with prostate cancer were more responsive to immunotherapy. Here, the authors analysed prostate cancer gene expression profiles and show tumours from Black men and men with African ancestry have an increased proportion of plasma cells compared to those of White men and this correlates with improved outcome following treatment. [ABSTRACT FROM AUTHOR]