Quantification of EGFR family in canine mammary ductal carcinomas in situ: implications on the histological graduation.

The epithelial growth factor receptors are transmembrane proteins with an important role in the neoplastic progression of tumors, and in this context, DCIS is an important phase in the progression of canine mammary tumors. Studies on the molecular profile and its relationship to a progression of canine mammary tumors are important to improve the treatment of patients and for a better understanding of canine mammary carcinogenesis. The aim of this study was to determine, by immunohistochemistry, the relation between the expression of EGFR, ErbB-2, ErbB-3, and ErbB-4 in 52 canine mammary gland DCIS with high and low histological grade. A positive correlation between histological grade and expression of membrane ErbB-2 and cytoplasmic ErbB-4 was observed. Increased ErbB-4 membrane expression was correlated with increased ErbB-3 expression in low and high-grade DCIS. Our data suggest that increased expression of ErbB-2 and ErbB-4 may be related to more aggressive DCIS and probabily involved with canine mammary neoplastic progression.