Breast cancer molecular subtypes in patients with locally advanced disease: impact on prognosis, patterns of recurrence, and response to therapy.

Gene expression profiling has led to the discovery of 4 distinct molecular subtypes of breast cancer: luminal A, luminal B, basal like, and HER2 enriched. Investigation of these subtypes in women with breast cancer has given insight into the heterogeneous biology and outcomes in patients with locally advanced disease. These subtypes have been found to be predictors for survival, response to systemic therapy, and locoregional recurrence. This review discusses the biology of locally advanced breast cancer and the available data on how molecular subtype may provide information regarding response to treatment and prognosis of women with locally advanced breast cancer.