Integrated Study of Canine Mammary Tumors Histopathology, Immunohistochemistry, and Cytogenetic Findings

abstract

Simple Summary Canine mammary tumors are the most common tumor in intact female dogs. This study aimed to investigate the clinicopathological, immunohistochemical, and cytogenetic features of canine mammary tumors. This study is relevant due to the fact that canine and human breast cancer share similar epidemiological and histopathological characteristics, reinforcing the potential for dogs to serve as an effective animal model for human breast cancer research.Abstract Cancer is a complex pathological condition associated with substantial rates of mortality and morbidity in both humans and animals. Mammary gland tumors in intact female dogs are the most prevalent neoplasms. Surgical intervention remains the primary treatment choice. Alternative therapeutic options have emerged, with histopathological examination being fundamental to confirm the diagnosis and to decide the best therapy. This research focused on the clinicopathological, immunohistochemical, and cytogenetic aspects of canine mammary tumors (CMTs). Most of the animals were mixed-breed, with the majority being older than seven years, and only 16.7% had been spayed before surgery. Caudal abdominal and inguinal mammary glands were the most affected, with regional mastectomy being the predominant treatment (75.0%). Of all the tumors, 29.1% were benign, while 70.9% were malignant. Complex adenoma was the most common benign tumor, whereas tubulopapillary carcinoma was the most common malignant type. Grade III tumors (17.6%) were the least encountered, while grades I and II exhibited a similar prevalence (41.2%). All the carcinomas were classified as luminal, and cytogenetics analysis demonstrated a high chromosomal instability with significant aneuploidy observed in all cases and polyploidy detected in 62.5%. This study holds significance as canine and human breast cancers share similar characteristics, suggesting that dogs could be a valuable model for human breast cancer research. Further studies with larger sample sizes are needed to enhance our understanding of CMTs.

keywords

PROGNOSTIC VALUE; GLAND TUMORS; RISK-FACTORS; DNA-PLOIDY; CANCER; CARCINOMAS; CONSENSUS; BENIGN; AGE; MARKERS

subject category

Veterinary Sciences

authors

Ferreira, T; Miranda, M; Pinto-Leite, R; Mano, JF; Medeiros, R; Oliveira, PA; Gama, A

Groups

G5 - Biomimetic, Biological and Living Materials

Projects

CICECO - Aveiro Institute of Materials (UIDB/50011/2020)

CICECO - Aveiro Institute of Materials (UIDP/50011/2020)

Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)

acknowledgements

This work was supported by National Funds from FCT-Portuguese Foundation for Science and Technology, under the projects UIDB/04033/2020 (https://doi.org/10.54499/UIDB/04033/2020), LA/P/0126/2020, UIDB/00772/2020 (https://doi.org/10.54499/UIDB/00772/2020), LA/P/0059/2020, and through a doctoral grant with 2020.04789.BD (https://doi.org/10.54499/2020.04789.BD). This work was also developed within the scope of the Project CICECO-Aveiro Institute of Materials, UIDB/50011/2020 (DOI 10.54499/UIDB/50011/2020), UIDP/50011/2020 (DOI 10.54499/UIDP/50 011/2020), LA/P/0006/2020 (DOI 10.54499/LA/P/0 0 06/2020), financed by national funds through the FCT/MEC (PIDDAC).