OVEREXPRESSION OF P53 PROTEIN IN MALIGNANT BREAST TUMORS: AN IMMUNOHISTOCHEMICAL STUDY

The P53 protein is expressed in all normal cells and appears to function in cell cycle regulation. Abnormally higli levels of the protein are found in many different types of cancer. In breast cancer, overexpression of P53 is associated with point mutations within highly conserved regions of the P53 gene. These altered genes encode stable P53 protein that can be detected by standard immunohistochemical techniques."nIn this study, we examined 47 cases of primary breast carcinoma for the presence of P53 protein using immunohistochemistry methods employing monoclonal antibody against the clone, DO-7. Of these specimens, 25.5% had widespread overexpression of P53. A significant positive correlation waz found between P53 overexpression andyounger age (P<0.05). There was a tendency for P53 overexpression in premenopausal women and the higher tumor grades, although! these did not acheive significance. The P53 overexpressoin was not correlated with tumor size, tumor type, nodal status and side of involved breast. The overexpressoin ofP53 may itself be a prognostic factor in human breast cancer.