Laryngeal Squamous Cell Carcinoma Is Characterized by a Stronger Expression of Nectin-4 Compared to Nectin-2

Nectin-2 and Nectin-4 are cell adhesion molecules associated with the progression of various cancers. The main goal of this pilot study was to evaluate the expression patterns of Nectin-2 and Nectin-4 in laryngeal squamous cell carcinoma (LSCC). A retrospective study was conducted on tissue microarray (TMA) samples derived from 31 patients who underwent total laryngectomy. The findings revealed heterogenous expression of both Nectin-2 and Nectin-4 in tumor cells and surrounding stroma, with Nectin-4 expression being significantly higher than Nectin-2 expression. Specifically, 74% of cases showed weak cytoplasmic staining for Nectin-2, while 41.93% exhibited strong cytoplasmic staining for Nectin-4. Both Nectin-2 and Nectin-4 expressions were more pronounced at the invasive tumor margins. Although no significant differences in Nectin-4 expression were observed across tumor grades (W = 83.500; z = -0.463; p = 0.658), differences in expression patterns were noted. Well-differentiated tumors (Grade 1), 80.65% of cases, showed predominantly membranous Nectin-4 staining, including in squamous epithelial cells of the mucosal surface. Conversely, in less-differentiated tumors (Grade 2 and 3), a shift toward cytoplasmic staining was evident. Specifically, 74.19% of Grade 2 tumors and 100% of Grade 3 tumors showed a predominant cytoplasmic localization of Nectin-4. This transition from membranous to cytoplasmic localization was also evident in the progression from normal superficial epithelium to malignant tissue. These observations suggest that alterations in the expression and subcellular localization of Nectin-4 may be associated with carcinogenesis and could serve as potential markers for the assessment of precancerous lesions and the aggressiveness of laryngeal tumors.