Triple Negative Breast Cancer (TNBC) is defined by a lack of expression of ER, PgR and HER-2. DNA microarray profiling studies have led to the classification of invasive breast carcinoma into five subtypes: luminal A and B, normal breast-like, HER2/neu overexpressing and basal-like subtypes, with clinical implications. Later on, a new subtype, the claudin-low, has been described. Although not synonymous, the majority of TNBCs carry the basal-like breast cancer (BLBC) molecular profile. The triple negative subtype accounts for 11-20% of breast cancer in different studies, whereas in selected cohorts of patients with advanced breast cancer or African-American ethnicity, TNBC may be diagnosed among as many as 23-28%. Patients with TN breast tumors treated with standard chemotherapy have a shorter DFS and OS than non-TNBC, this difference have been shown to be independent from tumor grade, nodal status and treatment in some studies. The peak risk of recurrence occurs within the first 3 years after initial treatment, with the majority of deaths occurring in the first five years.