Basal-like subtype of breast cancer: a review of its unique characteristics and their clinical significance.

Subtyping of breast cancers by means of DNA microarray analyses has given rise to the new concept of the basal-like subtype; this subtype is in effect the equivalent of so-called "triple-negative" breast cancer. Basal-like breast cancer has aggressive characteristics, such as high histological grade, mutation of the TP53 gene, and negative hormone receptors. It tends to occur in relatively young women and is highly correlated with suppression of BRCA1 function. The EGFR gene is often overexpressed in this subtype. Here, research carried out in the last few years into the basal-like subtype of breast cancer will be reviewed.