Quantification of infiltrating T lymphocytes in mammary carcinomas of bitches and their relationship with prognosis

• Grant number: 24/13310-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: October 01, 2024
• End date: September 30, 2025
• Field of knowledge: Agronomical Sciences - Veterinary Medicine - Animal Pathology
• Principal Investigator: Ricardo de Francisco Strefezzi
• Grantee: Débora Peccin do Nascimento
• Host Institution: Faculdade de Zootecnia e Engenharia de Alimentos (FZEA). Universidade de São Paulo (USP). Pirassununga , SP, Brazil

Abstract

Mammary tumours are the most frequent neoplasms in women and dogs, accounting for 50 to 70% of all neoplasms diagnosed in non-spayed female dogs. Clinically, mammary tumours may occur as single or multiple nodules within the mammary gland, and are associated with the glandular tissue or the teat. Different populations of cells influence tumorigenesis in the tumour microenvironment, such as T lymphocytes, which have been associated with angiogenesis, higher incidence of metastases, cell proliferation and shorter survival time. The objective of this study is to quantify T lymphocytes in canine mammary carcinomas, evaluate their relationship with other markers and verify their prognostic value. For this purpose, histological samples of canine mammary carcinomas will be submitted to immunohistochemical analysis for the detection of T lymphocytes. CD3+ cells will be quantified by counting in 5 fields with the higher T lymphocyte infiltration ("hot spots"). An analysis of the whole slide will also be performed, based on its distribution pattern, as: absent, brisk (diffuse infiltrate) or nonbrisk (focal or multifocal infiltrate). The results will be compared with the histological subtypes and grades, mitotic index, presence of lymph node and/or distant metastasis, and post-surgical survival.