Mel-CAM Expression in Common Oral Carcinomas

Mel-CAM (CD₁₄₆, MUC₁₈) is a 113-kD heterophilic cell-cell adhesion glycoprotein found in normal and tumoral tissues. The biologic functions and role of the Mel-CAM can be employed as a diagnostic marker in pathology.

The aim of this study was assessing the expression of Mel-CAM in common oral carcinomas like salivary gland mucoepidermoid carcinoma (MEC) and oral squamous cell carcinoma (OSCC) to differentiate the OSCC from high-grade MEC.

This study was performed on 19 specimens of MEC and 17 specimens of OSCC, which were retrieved from the archive of Department of Pathology of Taleghani Hospital, Tehran, Iran. Immunohistochemical staining was performed by using antibody against CD₁₄₆. The data were analyzed using SPSS software through Mann-Whitney, Spearman's correlation coefficient, and Kruskal-Wallis tests.

Mel-CAM was expressed in all MEC samples and 10 OSCC cases. The two groups were significantly different regarding the CD₁₄₆ expression (p= 0.035). Furthermore, the CD₁₄₆ expression was found to be significantly correlated with the invasion mode (p= 0.002), tumor size (p= 0.012), and histological grade (p= 0.024) in OSCC group. No significant correlation existed between the expression, intensity, and location with the histological grade of MEC (p> 0.05) nor was any significant correlation detected between the CD₁₄₆ expression and lymph node metastasis in neither group.

Regarding the significant correlation between the CD₁₄₆ expression and the prognostic factors in OSCC, this marker may predict the prognosis in OSCC patients, but not the MEC lesions. It cannot be used for differentiating high-grade MEC and OSCC.