Diagnostic and Prognostic Value of ProEx C and GLUT1 in Melanocytic Lesions.

Background: Melanoma is one of the most aggressive types of skin cancer. The purpose of this study was to evaluate the use of two biomarkers, ProEx C and glucose transporter isoform 1 (GLUT1), in the diagnosis and prognostication of melanoma. Materials and Methods: We analyzed 129 melanomas and 59 benign nevi in a tissue microarray using immunohistochemical method with antibodies to topoisomerase IIa (TOP2A) and minichromosome maintenance complex component 2 (MCM2) using ProEx C and to GLUT1. Results: The average proliferative index by ProEx C immunostain was significantly higher in melanomas (37.5%) compared to benign nevi (1.9%) as was the expression of GLUT1 (p<0.0001 respectively). Dermal mitosis was found to correlate positively with both ProEx C and GLUT1 (p=0.003 and p<0.001, respectively). Ulceration and tumor thickness positively correlated with GLUT1 expression (p=0.013 and p=0.033, respectively), but not with ProEx C staining. There was a significant association between increasing ProEx C index and stronger expression of GLUT1 (p<0.001). Kaplan-Meier disease-specific survival analyses indicated that patients whose melanoma exhibited expression of GLUT1 had a significantly lower rate of disease-specific survival than patients whose melanoma did not (p=0.039). However, staining by ProEx C did not show a prognostic significance in disease-specific survival. Conclusion: ProEx C and GLUT1 are potentially useful markers in differentiation of melanoma from nevi. Absence of GLUT1 expression in patients with primary melanoma predicts better survival.