Integrated microRNA and mRNA Signatures Associated with Survival in Triple Negative Breast Cancer

Triple negative breast cancer (TNBC) includes basal and non-basal subclasses. To further stratify TNBC we determined microRNA (miRNA) and mRNA expression profiles, linked specific miRNA signatures to patient survival and used miRNA/mRNA anti-correlations to identify TNBC subclasses associated with expression of canonical signal pathways RNA was isolated from formalin-fixed paraffin-embedded tissue cores of 165 primary tumors, 59 adjacent normal and 54 lymph node metastatic samples and expression of 664 miRNAs and 230 cancer-associated mRNAs was assessed for each sample using the nanoString nCounter platform. Kaplan-Meier distant-disease free and overall survival curves were compared using the log-rank test. Cox proportional hazard regression and risk score analysis were used to identify miRNAs for classification of patients with significantly different prognoses.