Immunohistochemical Evalution of Human P53 Tumor Suppressor Protein Content in Ductal Carcinoma in Situ of the Breast.

The focus of this study was to determine if early detection of mutant p53 accumulation may be an early indicator of tumor aggressiveness and transformation to invasive breast cancer. For this purpose, the p53 content of 100 human breast biopsies classified as ductal carcinoma (DCIS), was evaluated by immunohistochemical method. All specimens were microscopically classified into histologic types of DCIS and nuclear grade. From this population, 15 specimens were immunopositive and six of them were converted to more invasive form. Most immunopositive specimens were classified as mixed histologic types. No relationship between nuclear grade and different histologic types of DCIS was noticed. Preliminary data indicated that the presence of immunopositive p53 may be a valid predictive indicator of the prognosis of individuals with DCIS and transformation to invasive breast cancer.