Tumori mammari negli animali da compagnia: microambiente tumorale e prospettive terapeutiche

Mammary tumours are common in intact bitches and queen. Diagnosis, confirmed by histopathology and, if necessary, immunohistochemistry, is important in determining treatment and prognosis. The elective treatment is surgery, which aims to remove the tumour with clean margins and, depending on the case, to prevent the development of new tumours in the remaining glands. Adjuvant therapy may include chemotherapy and immunotherapy. In recent years, it has become clear how tumours and the tumour microenvironment represent spatially organised “ecosystems”, where tumour cells and the immune cells of the different compartments (stromal, intratumoral and peritumoral), are in dynamic interaction, with a potential clinical impact. For this reason, the aim of this doctoral thesis is to investigate the prognostic significance of the inflammatory infiltrate in canine and feline mammary tumours through the study of the tumor- infiltrating lymphocytes (TILs) and tertiary lymphoid structures (TLSs) to obtain useful information for understanding the behaviour of the neoplasm that could be useful for collecting prognostic data and set up therapeutic protocols. Results suggest that the distribution of TILs and TLSs in the tumour compartment (stromal, intratumoral and peritumoral) may have different prognostic values in mammary simple carcinomas. Among cat mammary lesions, the so-called fibroadenomatous change (FAC), a hyperplastic/dysplastic lesion of the feline mammary gland, is frequently encountered in clinical practice; although non-neoplastic and non-malignant, FAC is painful and disabling for the patient. In this thesis, a new therapeutic protocol for the treatment of FAC is described, involving a combination of drugs designed to preserve mammary gland integrity, even in pregnant queens.