Correlation between E-cadherin expression and tumor grade, proliferation, microvascular density, and apoptosis in canine cutaneous squamous cell carcinoma.

E-cadherin is an adhesion molecule expressed on epithelial surfaces. Loss of its expression is described in cancerous tissues. Here, we examined the expression of E-cadherin in canine cutaneous squamous cell carcinoma (SCC) and determined its association with tumor grade (TG), proliferation index (PI), apoptosis index (AI), and intra-tumoral microvascular density (iMVD) in archived samples. Thirty-six cutaneous SCC samples (archived from 2014 to 2019) were graded and E-cadherin level, Ki67 (PI), von Willebrand factor (iMVD), and apoptosis (AI) were determined immunohistochemically. Tumor grades were assigned as Grade 1 (n = 18), Grade 2 (n = 16), and Grade 3 (n = 2). Of the 36 tumors, 21 were digital and 15 were from other locations, including the tail, neck, ear, and elbow. The median E-cadherin score decreased statistically (P = 0.03) with an increase in TG. There was a negative association between median E-cadherin score and TG (r = -0.445, P = 0.013), AI (r = -0.342, P = 0.08), and PI (r = -0.459, P = 0.016). The median E-cadherin score was significantly higher in digital SCC compared to SCC from other locations (P = 0.035). In conclusion, a negative association was observed between TG, PI, AI, and E-cadherin.