Tumor-infiltrating CD4and CD8lymphocytes and macrophages are associated with prognostic factors in triple-negative canine mammary complex type carcinoma.

Abstract

This study aimed to evaluate the association of CD3, CD4, and CD8T cells and tumor-infiltrating macrophages (TIMs) with the clinical parameters of female dogs harboring mammary gland tumors. Thirty female dogs affected with mammary carcinomas were used, and all tumors were histologically classified as complex carcinoma and were triple-negative phenotype determined by immunohistochemistry. Freshly frozen sections were used to determine CD3, CD4and CD8T cells by immunohistochemistry, and TIMs were determined by immunofluorescence assays. Ten out of the 30 dogs showed lymph node metastasis at diagnosis. Fifteen dogs had a tumor of grade I (15/30), nine (9/30) had a tumor of grade II and six (6/30) had a tumor of grade III. The mean overall survival was 680.5&#x202f;days (&#xb1; 200.4). Dogs with sentinel lymph node positivity (10/30) (P&#x202f;=&#x202f;.0035) and dogs that developed metastasis (P&#x202f;=&#x202f;.0001) showed a shorter survival time. In addition, dogs with a high level of inflammatory infiltrate in tumor tissues presented a shorter survival time (P&#x202f;=&#x202f;.0001) than that of other dogs. Dogs with tumors containing higher numbers of CD3+ T cells (P&#x202f;=&#x202f;.001), CD4+ T cells (P&#x202f;=&#x202f;.001), or TIM cells (P&#x202f;<&#x202f;.0001) showed a shorter survival time than that of other dogs. Our results suggested that characteristics of immune cell infiltrates, including CD3T cells, CD4T cells, and TIMs, can be used as potential prognostic indicators for predicting clinical outcomes in dogs with mammary gland tumors, particularly tumors with a complex histological subtype and triple-negative phenotype.