Prognostic phenotypic classification for canine mammary tumors

Area of Science:

• Veterinary Oncology
• Canine Pathology
• Immunohistochemistry

Background:

• Mammary neoplasms in dogs are diverse, necessitating accurate classification for prognosis.
• Phenotypic characterization is crucial for understanding tumor behavior and patient outcomes.

Purpose of the Study:

• To propose and validate a phenotypic classification for canine mammary tumors.
• To assess the association between clinicopathological characteristics, survival, and prognosis based on tumor phenotypes.

Main Methods:

• Immunohistochemistry was employed using primary antibodies for estrogen receptor-α, progesterone receptor, human epidermal growth factor receptor 2 (HER-2)/neu, and E-cadherin.
• A total of 110 canine mammary tumors were phenotypically classified into luminal A, luminal B, triple-negative, and HER-2-positive groups.

Main Results:

• Luminal A and B phenotypes were linked to improved prognosis.
• HER-2-positive and triple-negative tumors demonstrated more aggressive behavior, with increased metastasis and shorter survival times.
• E-cadherin expression was upregulated in luminal A and B phenotypes compared to HER-2-positive and triple-negative phenotypes.

Conclusions:

• The proposed immunohistochemical panel and phenotypic classification are valuable diagnostic tools in veterinary oncology.
• E-cadherin expression analysis aids in accurately determining the biological features and prognosis of canine mammary tumors.