Nuclear Localization of β-catenin Associates EMT with Aggressive Vulvar Squamous Cell Carcinoma

Nuclear localization of β-catenin in epithelial cells characterizes the epithelial-mesenchymal transition (EMT) and is associated with tumor progression in numerous malignancies. Factors that contribute to aggressive behavior in vulvar squamous cell carcinoma (vSCC) are poorly defined; however, studies have shown that vSCC with an infiltrative pattern of invasion are associated with worse outcomes compared to those with nested/pushing patterns of invasion. This study proposes that infiltrative vSCC may acquire increased aggressive behavior through EMT-like changes reflected by nuclear localization of β-catenin. Immunostaining patterns of β-catenin were analyzed in 30 cases of vSCC: 10 cases with infiltrative pattern of invasion, 10 with nested/pushing pattern of invasion, and 10 with a “mixed” invasive pattern. Stained tumor sections were analyzed for nuclear localization or membranous staining of β-catenin. A staining pattern was defined as predominant when present in >75% of tumor cells. Predominant nuc...