Serum proteomics links suppression of tumor immunity to ancestry and lethal prostate cancer

There is evidence that tumor immunobiology and immunotherapy response may differ between African American and European American prostate cancer patients. Here, we determined if men of African descent harbor a unique systemic immune-oncological signature and measured 82 circulating proteins in almost 3000 Ghanaian, African American, and European American men. Protein signatures for suppression of tumor immunity and chemotaxis were significantly elevated in men of West African ancestry. Importantly, the suppression of tumor immunity protein signature associated with metastatic and lethal prostate cancer, pointing to clinical significance. Moreover, two markers, pleiotrophin and TNFRSF9, predicted poor disease survival specifically among African American men. These findings indicate that immune-oncology marker profiles differ between men of African and European descent. These differences may contribute to the disproportionate burden of lethal prostate cancer in men of African ancestry. The elevated peripheral suppression of tumor immunity may have important implication for guidance of cancer therapy which could particularly benefit African American patients.