There is a lack of investigations assessing the performance of systemic inflammation indices as outcome predictive tools in African Americans with prostate cancer. This study aims to assess the relationships between neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), systemic immune-inflammation (SII), and systemic inflammation response index (SIRI) with survival outcomes among 680 diverse men with prostate cancer. Routine blood results were collected from self-identified African American and European American patients. We applied multivariable Cox regression modeling to examine the associations of systemic inflammation indices with overall and prostate cancer-specific survival. The median survival follow-up was 5.9 years, with 194 deaths. NLR, SII, and SIRI, but not PLR, showed associations with all-cause and prostate cancer-specific mortality when coded as dichotomized and continuous variables. NLR and SIRI were significantly associated with prostate cancer-specific mortality among all men (hazard ratio (HR) 2.56 for high vs. low NLR; HR 3.24 for high vs. low SIRI) and African American men (HR 2.96 for high vs. low NLR; HR 3.19 for high vs. low SIRI). Among European Americans, only SII showed an association with prostate cancer-specific survival. These observations suggest that inflammation indices merit further study as predictors of prostate cancer mortality.
Keywords: African American; health disparity; inflammation; prostate cancer; systemic inflammation indices.