Breast cancer: new concepts in classification

Breast cancer is the principal cause of death from cancer in women. Molecular studies of breast cancer, based in the identification of the molecular profiling techniques through cDNA microarray, had allowed defining at least five distinct sub-group: luminal A, luminal B, HER-2-overexpression, basal and "normal" type breast-like. The technique of tissue microarrays (TMA), described for the first time in 1998, allows to study, in some samples of breast cancer, distinguished by differences in their gene expression patterns, which provide a distinctive molecular portrait for each tumor and the basis for and improved breast cancer molecular taxonomy. Another important implication is that genetic profiling may lead to the identification of new target for therapy and better predictive markers are needed to guide difficult treatment decisions. Additionally, the current pathology classification system is suboptimal, since patients with identical tumor types and stage of disease present different responses to therapy and different overall outcomes. Basal breast tumor represents one of the most intriguing subtypes and is frequently associated with poor prognosis and absence of putative therapeutic targets. Then, the purpose of this review was to resume the most recent knowledge about the breast carcinoma classification and characterization.