Can analysis of the molecular status of the p53 gene contribute to improving the therapeutic strategy for breast carcinoma?

The occurrence of mutations in the p53 tumor suppressor gene is a specific and recurring genetic event in solid tumors. P53 plays a pivotal role in multiple cellular processes such as cell growth control, DNA repair and programmed cell death. Genotoxic damage, also induced by chemotherapy or radiotherapy, induces p53 overexpression in order to control the rate of proliferating damaged cells, thus triggering the mismatch repair or apoptotic pathways. P53 inactivation determines a condition of genetic instability, justifying the subsequent susceptibility to acquire mutations of different other genes. P53 mutations are associated with worse prognosis and with chemo/radioresistance, due to the inability to trigger p53-dependent programmed cell death. Molecular diagnostic strategies show 32% p53 mutations in breast cancer. The analysis of the p53 gene performed by FAMA (Fluorescence Assisted Mismatch Analysis) in high-risk breast cancer patients with > or = 10 involved axillary nodes may help identify a subset of very high risk BC patients (vHR-BC) with poorer prognosis and a subset with better prognosis, potentially responsive to medical treatments. The accurate evaluation of the p53 status can predict prognosis and sensitivity to chemotherapy, thus representing the first step toward better definition of therapeutic strategies according to the molecular characterization of the individual patient.