Pan-immune-inflammation value: racial variations and differences in prognostic accuracy across breast cancer subtypes at a single institution

Introduction The Pan-Immune-Inflammatory-Value (PIV) has shown promise as a biomarker for predicting survival outcomes in breast cancer (BC) patients. This study explores the variation of PIV across BC subtypes, with a focus on triple-negative BC (TNBC), hormone receptor positive and negative (HR+ and HR-) cancers, and racial disparities in immune response. Methods A retrospective review of laboratory and clinical data of 2,597 BC patients treated between 2012–2022 was conducted. PIV was calculated as a composite marker of neutrophils, monocytes, lymphocytes, and platelets. Comparative analysis of PIV with race, subtype and stage was performed using Man-Whitney. For categorical analysis of PIV, receiver operating characteristic curve was generated, and the optimal cutoff point was determined using the Youden index (cutoff = 395). Descriptive and inferential tests were used to compare high/low PIV groups based on race and BC subtype. Disease-free survival (DFS), and overall survival (OS) were evaluated with Kaplan-Meier curves and Cox regression analysis. Results PIV varied significantly by race and subtype; Black women were significantly less likely to present with high PIV (OR = 0.595, 95% CI: 0.505 – 0.701) compared to White women. Lower values were also observed in Black women, TNBC patients and those with HR− tumors. Over a median follow-up of 55.4 months, high PIV was associated with worse DFS and OS in the overall cohort (p < 0.0005). Subgroup analysis showed high PIV predicted shorter DFS in both Black and White women but was not associated with OS in Black women or DFS in TNBC. In multivariable Cox regression, stage and PIV independently predicted DFS and OS. Significant interactions were observed between PIV and both race and subtype for breast cancer outcomes. Conclusion While PIV shows promise as a general prognostic indicator, its predictive accuracy varies across different receptor subtypes. In HR+ BC patients, PIV is linked to clinical outcomes, supporting its role as a prognostic biomarker. However, further research is needed to assess the use of PIV as a prognostic biomarker.