PROGNOSTIC VALUE OF CELL PROLIFERATION IN CANINE MALIGNANT MAMMARY TUMOURS

The aim of the study was to assess the prognostic Value Of Cell proliferation for the continuing course of the disease after the surgical excision of malignant mammary tumours in female dogs. The expression of the proliferating cell nuclear antigen (PCNA) and Ki-67 antigen has been determined by means Of immunohistochemistry in formalin-fixed, paraffin-embedded tumour tissue samples taken during the mastectomy. Differences in the) intensity of cell nuclei staining have been observed between the PCNA and Ki-67 antigens. The PCNA index was generally twice as high as that of Ki-67; however, the Ki-67 antigen index achieved higher values in predicting the remission time and survival time than the PCNA index. At the same time, only the mean value of the Ki-67 antigen index was statistically higher in the group of dogs with disease progression, than in the groups of dogs without recurrence and metastases. The PCNA index values demonstrated a positive correlation with the degree of histologic malignancy. The results confirm that the determination of the Ki-67 antigen index has a higher prognostic value, especially in the context of its introduction into a standard histopathological examination.