A MicroRNA Expression Signature in Breast Tumor Tissue is Associated with Risk of Distant Metastasis

Dysregulation of microRNA (miRNA) expression may influence breast cancer progression, and experimental evidence suggests that miRNA silencing might suppress breast cancer metastasis. However, the relationship between miRNA and metastasis must be confirmed before this approach can be applied in the clinic. To this end, we conducted a 2-stage study in a cohort of 3760 breast cancer patients to first identify and then validate the association between miRNA expression and risk of distant metastasis. The first stage (discovery) entailed miRNA sequencing of 126 case-control pairs; qPCR was used to validate the findings in a separate set of 80 case-control pairs. The 13 miRNAs most differentially expressed between cases and controls were combined into an miRNA score that was significantly associated with risk of distant metastasis in a logistic regression model that also included clinical variables (tumor size and number of positive lymph nodes) (ORper unit increase in score=1.30, 95% CI=1.03-1.66). The results of this study suggest that in women with invasive breast cancer, an miRNA score that incorporates both clinical variables and miRNA expression levels in breast tumor tissue is moderately predictive of risk of subsequent distant metastasis.

http://bit.ly/2N4Xhnb