Evaluation of proliferative markers in canine mammary tumours

The present investigation was carried out with an aim to study the different proliferative cell markers in spontaneous canine mammary tumours. Out of 67 suspected tumours cases, 63 were histopathologically confirmed as tumours with higher occurrence of malignant (50) than benign tumours (13). Benign tumours were identified as cystic fibroadenoma (7), benign mixed mammary tumour (3), papillary adenoma (2) and myoepithelioma (1). The malignant mammary tumours were malignant mixed mammary tumour (13), papillary adenocarcinoma (12), adenocarcinoma (10), solid carcinomas (8) and malignant myoepithelioma (7). There was significant difference in different proliferative markers, argyrophilic nucleolar organizer region (AgNOR), proliferative cell nuclear antigen (PCNA) and proliferative cell nuclear protein Ki-67 (Ki-67) indices between benign and malignant tumours except in mitotic index. There was also significant correlation between AgNOR, PCNA and Ki-67 indices (P<0.01) with Ki-67 index being highly sensitive than PCNA in differentiating and determining the proliferation rate of malignant and benign tumours.