The immunocytochemical expression of p53 protein and Ki-67 labelling index
in tumour cells of 100 ductal breast carcinomas of different histological g
rade and stage was evaluated in cytological material. In order to investiga
te p53 expression and Ki-67 expression an avidin-extravidin immunocytochemi
cal technique was applied to imprints. Monoclonal antibody (MoAb) DO-p53 an
d proliferating cell monoclonal antibody were used as primary antibodies. A
statistically significant difference was observed between p53 protein expr
ession and grade of malignancy and clinical stage (P = 0.001, P < 0.001, re
spectively). A statistically significant difference was also observed betwe
en 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 exp
ression and Ki-67 LI (P < 0.001). The immunocytochemical study of p53 prote
in and Ki-67 expression in cytological material represents a simple method
which can be applied in routine cytological laboratories for the investigat
ion of potential malignancy of ductal breast cancer.