p53 protein expression and proliferative activity in ductal breast carcinomas

The immunocytochemical expression of p53 protein and Ki-67 labelling index in tumour cells of 100 ductal breast carcinomas of different histological grade and stage was evaluated in cytological material. In order to investigate p53 expression and Ki-67 expression an avidin-extravidin immunocytochemical technique was applied to imprints. Monoclonal antibody (MoAb) DO-p53 and proliferating cell monoclonal antibody were used as primary antibodies. A statistically significant difference was observed between p53 protein expression and grade of malignancy and clinical stage (P = 0.001, P < 0.001, respectively). A statistically significant difference was also observed between Ki-67 LI and histological grade and stage of the tumours (P < 0.001, P < 0.001 correspondingly). A correlation was observed between p53 protein expression and Ki-67 LI (P < 0.001). The immunocytochemical study of p53 protein and Ki-67 expression in cytological material represents a simple method which can be applied in routine cytological laboratories for the investigation of potential malignancy of ductal breast cancer.