Clinicopathologic significance of dysadherin expression in cutaneous malignant melanoma: Immunohistochemical analysis of 115 patients

BACKGROUND. The E-cadherin-mediated cell adhesion system is frequently inactivated by multiple mechanisms and is involved in tumor progression in many types of cancer. Recently, the authors reported a novel cell membrane glycoprotein, dysadherin, which has an anti-cell-cell adhesion function and down-regulates E-cadherin. METHODS. Expression of both dysadherin and E-cadherin was investigated immunohistochemically in 115 patients with cutaneous malignant melanoma to determine the correlation between the 2 molecules and their associations with both patient survival and the clinicopathologic features of the tumors. RESULTS. Dysadherin and E-cadherin were expressed at the cell membranes of melanoma cells. Fifty-two percent of the tumors showed dysadherin immunopositivity, and 91% of the tumors showed reduced E-cadherin immunopositivity. There was no significant inverse correlation between dysadherin expression and E-cadherin expression. Increased dysadherin expression was significantly correlated with nodular subtype (P = 0.042), Clark level (P < 0.001), tumor thickness (P < 0.001), ulceration (P = 0.008), lymph node metastasis (P < 0.001), high TNM classification (P < 0.001), and poor patient survival (P < 0.001). Multivariate analysis of patient survival revealed that increased dysadherin expression was a significant predictor of poor survival (P < 0.001). CONCLUSIONS. Thus, increased expression of dysadherin was a significant indicator of poor prognosis in patients with cutaneous malignant melanoma.