EN
The study aimed at monitoring the expression of oestrogen (ER) and progesterone (PGR) receptors in mammary gland adenocarcinomas in bitches as compared to the mitotic activity of the neoplastic cells. Material for the study involved samples of mammary tumors obtained during surgery from 48 bitches of various races, aged 7 to 15 years. The obtained preparations were microphotographed and the patterns were subjected to computer-assisted image analysis in a system consisting of a computer linked to an Axiophot light microscope (Carl Zeiss). The expression of ER, PgR and of Ki-67 was evaluated using a semi-quantitative scale which involved evaluating the proportion of positive cells (0-5% no reaction [], 6-25%: weak reaction [+], 26-50%: moderate reaction [++], above 50%: intense reaction [+++]). The evident deficit of ER observed in our studies might indicate an oestrogen independency of the adenocarcinomas in bitches. This, however, does not preclude involvement of the receptors at earlier stages of carcinogenesis. The obtained strong correlation between expressions of Ki-67 and that of PgR (r=0.67), in view of the high prognostic value of Ki-67 expression, confirmed in numerous studies, allow the conclusion that presence of progesterone receptors in the cells of mammary gland adenocarcinoma in bitches is linked to the augmented proliferative potential of the tumors, similarly as it has been demonstrated in mammary glands in females.