The prognostic significance of the activities of matrix metalloproteinases-2 and -9 in dogs for mammary gland neoplasia (pilot study)

The aim of this study was to determine the activity of matrix metalloproteinase-2 and -9 in blood and tumour tissue of female dogs with benign and malignant mammary gland neoplasias. The increased activity of matrix metalloproteinase-2 and -9 was registered in 3.8–8.9% of canines with benign neoplasias (adenoma, mixed tumour) and in 32.5–63.5% of those with malignant neoplasias (carcinoma: mixed type, ductal, tubular, tubulopapillary). Neoplastic transformation is accompanied by blood level increase of both latent and active enzyme forms. The dogs with malignant mammary gland neoplasias were diagnosed with credible increase of matrix metalloproteinases-2 activity up to 1.59–1.96 in blood plasma and up to 21.57–24.84 in tumour tissue and the increase of matrix metalloproteinases-9 activity up to 2.16–2.67 and 29.53–35.26 respectively. For benign mammary neoplasms, the proportion of dogs with enhanced expression of matrix metalloproteinase-2 was higher than the number of patients in whom an increase in the level of matrix metalloproteinase-9 or both of these enzymes was registered by 1.7 times, for dogs with malignant tumours – in blood plasma – by 1.4–1.6 times, dogs with neoplastic changed functional tissue – 1.7 and 1.9 times, respectively. Histological type and metastatic foci presence did not correlate with enzymes’ activity. The enzymes’ activity figures in benign neoplasias fluctuated within those in clinically healthy animals. A positive characteristic of determining the plasma and tissue expression level of matrix metalloproteinases in dogs with mammary tumours is the low degree of invasiveness of the method against the background of the high informativeness of the results obtained in the preoperative period. The obtained results prove the possibility of using matrix metalloproteinases-2 and -9 to predict the course and to control the treatment of mammary neoplasia.