Evaluation of EMMPRIN and MMP-2 in the prognosis of primary cutaneous malignant melanoma

The aim of the study was to investigate whether the presence of matrix metalloproteinase-2 (MMP-2) and its inducer, extracellular matrix metalloproteinase inducer (EMMPRIN), in primary cutaneous malignant melanoma (PCMM) might help to predict patient prognosis. Immunohistochemical staining was performed on formalin-fixed, paraffin-embedded sections of PCMM from 150 patients. Association of clinical variables (gender, age, tumor location, thickness, Clark level and AJCC stage) with EMMPRIN and MMP-2 expression were analyzed by Fisher's exact test. Survival rates were subsequently estimated using the Kaplan-Meier method and compared using the log-rank test. The expression of EMMPRIN and MMP-2 was detected in 117/150 (78.0%) and 115/150 (76.7%) of patients with PCMM, respectively. Higher positive rates of both EMMPRIN and MMP-2 expression were significantly correlated with increased tumor thickness (both P = 0.004), higher Clark level (P = 0.02 and 0.03) and higher AJCC stage (both P = 0.006). A significant correlation was found between the expression of EMMPRIN and MMP-2 in PCMM (r = 0.89, P = 0.01). Kaplan-Meier analysis demonstrated that patients who had EMMPRIN+/MMP-2+ expression had a significantly decreased 3-year disease-free survival (P = 0.005) and 5-year overall survival (P = 0.006). In multivariate analyses, tumor thickness and EMMPRIN+/MMP-2+ co-expression were the significant predictors of clinical outcome. EMMPRIN and MMP-2 may be independent biomarkers for disease recurrence and overall survival in patients with PCMM. A combined detection of EMMPRIN/MMP-2 co-expression may benefit us in prediction of a poor survival of PCMM.