Interest of investigating p53 status in breast cancer by four different methods

Alterations in the p53 gene are among the most common molecular changes in breast cancer although its potential role as a prognostic and predictive factor of tumor response is controversial. All abnormalities of this tumor marker need to be detected with efficacy and practical technologies. In the present study, our aim was to compare four different analyses of p53 in order to determine how many and which techniques were necessary and sufficient to reflect the p53 status in breast cancer. We analyzed p53 at the molecular level with sequencing of total cDNA and allelic loss. Furthermore, we detected p53 protein accumulation by immunohistochemistry and presence of p53 antibodies by serological analysis. Nine patients (17%) had p53 gene alterations, 33% had allelic loss, 19% had positive p53 nuclear staining and p53 antibodies were detected in 12% of patients. We found p53 gene alterations associated with p53 nuclear protein expression (p=0.001). The single significant statistical correlation in this study suggested the need to define p53 status with more than one abnormality. The general view of a simultaneous multilevel analysis would make it possible to encompass the consequences of p53 abnormalities in breast cancer.