Background: Alterations in the p53 tumor suppressor gene are most frequent genetic changes found in breast cancer, 
with an incidence reported in a range of 15 to 50%. This high rate of alteration suggests that the gene plays a central role in the development of breast cancer. Since p53 alteration can reflect a more advanced state of progression and a higher rate of proliferation, breast tumors that have a p53 alteration could have a greater probability of having micrometastasis. p53 alteration could therefore be a prognostic factor for recurrence after primary local therapy. 
Consistent with this hypothesis, this study was performed. Aminig at assessing p53 protein expression in different breast 
lesions to evaluate its significance and its correlation with other established prognostic factors. 
Methods: The study involved 40 patients with invasive mammary carcinoma and 10 patients with benign breast lesions. 
Results: p53 positive immunostaining has been correlated significantly with the tumor grade, but, did not correlate with 
tumor size, lymph node status, the age of patients and estrogen and progesterone receptors. 
Conclusion: The use of immunohistochemical detection of p53 protein overexpression is a simple, useful and reproducible technique. Unfortunately, its absence does not by itself define a group of patients whose risk of relapse is low enough that most physicians would consider not giving adjuvant therapy. The use of other factors in combination with p53 will be needed to achieve this goal