The aim of this study was 1) to explore alterations in the TP53 gene with respect to resistance to a regular dose epirubicin regimen (90 mg/m2 body surface every 3 week) in patient with primary, locally advanced, breast cancer; 2) To explore defects in potential mechanisms activating p53 in response to DNA damage in breast cancer as a cause of drug resistance in wild-type tumors. This evidence concerns the gene TP53 and breast cancer.