EN
The expression of p53 protein was determined by the immunohistochemical study with CM-1 polyclonal antibody. The investigations were performed on formalin-fixed and paraffin-embedded tissue samples of mammary tumours obtained from 131 bitches during surgery. The p53 protein accumulation was detected in 37 tumours (28.24%). No correlation was found between p53 protein overexpression and histological type, tumour size, or regional lymph node status. However, its relationship with a histologic malignant grade approached statistical significance (P=0.067). After the 24-month follow-up period, survival analysis revealed a shortened disease-free survival and overall survival time of the dogs with tumours, which overexpressed p53 protein. Only in the case of survival time, the difference was close to the borderline of statistical significance (P=0.061). The research data presented herein, being not fully explicit, have indicated a correlation of p53 protein accumulation with worse prognosis in canine mammary tumours, although the results do not allow recognising p53 protein accumulation as a suitable prognostic factor.