Investigation of some tumour biomarkers in canine mammary tumours related to clinicopathological parameters

The aim of this study is to evaluate the differences in tissue levels of oestrogen receptor (ER), progesterone receptor (PR), epidermal growth factor receptor (EGFR) and carbohydrate antigen 15-3 (CA 15-3) in benign and malignant mammary tumours in dogs. A total of 45 tumoural masses taken from 22 dogs with mammary tumours were included in the study. Based on the histopathological results of mammary tissues, study groups were formed as bening tumours (Group BT; n = 15) and malignant tumours (Group MT; n = 30) with Group MT divided into 2 subgroups as malignant epithelial tumours (Group MET; n = 16), carcinosarcomas and malignant mixed tumours (Group MMT; n = 14). Mean ER and EGFR levels in Group BT were significantly higher than both in Group MT (P < 0.01) and Group MET (P < 0.05). In Group MET, only PR levels exhibited significant differences related to the clinicopathological parameters. In conclusion, with the PR biomarker, a distinction can be made between Grade 2 and Grade 3 tumours and invasive or non-invasive tumours. It has been observed that these biomarkers can reveal the presence of the tumour and may be beneficial in evaluating the clinical and pathological characteristics of the tumour.