Syndecan-1 and E-Cadherin Expression in Canine Cutaneous Squamous Cell Carcinoma

Cutaneous squamous cell carcinoma (CSCC) in dogs is a locally invasive tumor that typically occurs in areas of poorly pigmented skin due to sun exposure. Identifying new biomarkers, such as syndecan-1 (CD138) and E-cadherin, is fundamental for tumor diagnosis and prognosis. Dysregulation of syndecan-1, expressed in epithelial tissue, fibroblasts, and plasma cells, is associated with poor prognosis in several types of cancer. Similarly, E-cadherin, which plays a crucial role in cell adhesion and epithelial functionality, is also linked to adverse outcomes. This study evaluated the expression of syndecan-1 and E-cadherin in 47 cases of canine cutaneous squamous cell carcinoma. The results showed that the intensity of syndecan-1 decreased with increasing tumor aggressiveness, and its presence in the stroma was significantly associated with tumor grade. E-cadherin also demonstrated a decrease in intensity with increasing malignancy. However, the association between syndecan-1 and E-cadherin was not statistically significant. E-cadherin reduction and stromal syndecan-1 positivity seem to be associated with tumor aggressiveness in canine cutaneous squamous cell carcinoma. Further studies are needed to explore their roles in tumor progression.