DIFFERENTIALLY EXPRESSED MIRNAS EXPLAIN RACIAL DIFFERENCES IN DIAGNOSIS STAGE AMONG TRIPLE NEGATIVE BREAST CANCER PATIENTS IN LOUISIANA.

Background: Triple-negative breast cancer (TNBC) is a highly aggressive subtype that disproportionately affects African American (AA) women, leading to worse survival rates and higher metastasis risks compared to Caucasian American (CA) women. MicroRNAs (miRNAs) are crucial in cancer development and hold promise as biomarkers, but their role in racial disparities in TNBC outcomes is unclear. Methods: This study used Louisiana Tumor Registry data and collected tumor tissues for miRNA sequencing to examine significant miRNAs differentially expressed by race and TNBC stages at diagnosis among 3,298 TNBC cases diagnosed from 2011 to 2017. Results: Of the TNBC cases, 49.7% were AA. AA patients were more often diagnosed at advanced stages (69.6% vs. 60.2%, p < 0.001). miRNA sequencing of 384 samples identified 88 miRNAs differentially expressed by cancer stage and 78 by race. Notably, 36 miRNAs were associated with both stage and race, with distinct expression patterns linked to breast cancer subtypes and pathways related to cellular stress and motility. Conclusions: These findings highlight distinct miRNA expression patterns between AA and CA women, offering insights for targeted interventions to reduce racial disparities in TNBC outcomes. The comprehensive dataset holds broad interest for scientists aiming to screen and validate biomarkers that explain racial differences in TNBC outcomes. It is publicly available through the Louisiana Tumor Registry and can be accessed upon request.