Abstract
Due to relevance of the problem, prediction of biological behaviour of neoplasias in mammary glands of dogs requires using contemporary approaches to the study, first of all, of ways of dissemination of tumour cells. One of them is studying the mechanisms of migration of cancer cells out of the neoplasm tissues with further dissemination and development of metastatic sites in the regional lymphatic nodes and remote tissues. We studied the survival period of bitches with tumours of the mammary glands following regional or unilateral mastectomy. Among malignant mammary tumours in bitches, the most often diagnosed were single tumours (57.5%), which histologically were classified to carcinomas – ductal (26.9%) and mixed type (21.9%). Probability of intratumoral invasion to blood vessels equaled 12.0%, to lymph vessels – 7.8%, lymph nodes – 12.8%. It depends on the histological type of the tumour, the most aggressive potentially being сomedocarcinoma, tubulopapillary carcinoma and ductal carcinoma. Parameters of life expectancy and survival level after mastectomy depend on clinical stage of the disease (increase in the stage from the first to the third was characterized by decrease from 12.8 ± 9.5 to 9.4 ± 7.8 months), presence of angio/lymphatic invasions, presence of angiolymphatic invasion, but had no correlation with the size of the tumours. An important predictor of tumour-related death of dogs suffering neoplasias of the mammary glands is index vet-NPI, which has significant correlation with the clinical stage according to Owen and median survival. In particular, median survival in patients with the index lower than 4 exceeded the corresponding values in dogs with the index above 4 by 1.3 times. A promising direction of further research would be studying biological mechanisms of development of tumour emboli in the blood and lymph vessels, metastatic sites in lymph nodes, and also determining their role in pathogenesis of canine mammary tumours.
Highlights
Despite the significant progress in diagnostics and treatment that has been achieved over the recent several decades, mammary gland tumours remain the global cause of early death of people and veterinary patients (Mysak et al, 2018; Terajima et al, 2021)
Canine mammary tumours are heterogenic diseases classified into sarcomas, carcinomas and carcinosarcomas according to the histopathologic differentiation (Turna et al, 2021); they are characterized by different biological behaviours (Im et al, 2014)
Mixed mammary tumours are the commonest type of tumours in the mammary gland of bitches; this form of neoplasia is associated with better predicted outcome than malignant tumours of other histological types (Cassali et al, 2012)
Summary
Despite the significant progress in diagnostics and treatment that has been achieved over the recent several decades, mammary gland tumours remain the global cause of early death of people and veterinary patients (Mysak et al, 2018; Terajima et al, 2021). Most studies on determining the level of aggressiveness of tumours of the mammary gland in dogs are related to studying correlative relations between relapses and metastases and age, clinical parameters and hormonal imbalance. In a multi-center retrospective study, Burrai et al (2020) demonstrated that the most significant factors of the prognosis are the size of the tumour and age of the animal. Presence of metastases in the regional lymph nodes is an important factor influencing the prediction and treatment in cases of mammary tumours (Collivignarelli et al, 2021). The level of methylation of DNA chains (evaluated by 5-methylcytosine) in mammary tumours correlates with size and prognosis for patients (Biondi et al, 2021)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
