Gene Signatures in the Management of Breast Cancer

A gene expression signature is a single or combined group of genes in a cell with a unique characteristic expression occurring due to altered biological processes or pathogenic medical conditions. These signatures could be clinically applied for prognostic, diagnostic, and predictive purposes. The goal of the incorporation of these signatures into clinical practice is to translate these changes at the genetic level into clinically meaningful phenotypes, predict the survival or prognosis of the individual with a disease, differentiate between various subtypes, and select a group of patients for whom a particular treatment will be effective (Fig. 11.1).