Heparanase expression correlates with poor survival in oral mucosal melanoma

Oral mucosal melanoma (OMM) is a lethal cancer with a poor prognosis. Despite the great interest in heparanase (HPSE) as a potential anticancer therapy target, the prognostic role of HPSE in oral mucosal melanoma has not been elucidated. In this study, we investigated HPSE expression in OMM tissues and examined its association with clinical outcome. A total of 81 patients with OMM were enrolled in this study. We examined the expression of HPSE in OMM, and its staining extent, intensity and cellular localization were analyzed for clinical significance. HPSE staining was positive in 81 % of tumors (66 of 81 patients) and was negative in the remaining 19 % (15 patients). The median survival time and the 5-year survival rate were 12 months and 7.0 % in the high-heparanase group, 35 months and 36.4 % in the low-heparanase group and 62 months and 53.3 % in the none-heparanase group (P = 0.001). In univariate survival analysis of oral mucosal melanoma, AJCC Stage, heparanase level, heparanase location and tumor size were the clinical parameters related to overall survival. In Cox analysis, overall survival time was significantly dependent on AJCC stage and heparanase level, but not tumor size and heparanase location. Heparanase is frequently expressed in oral mucosal melanoma, and its expression levels inversely correlate with the survival rates of OMM patients, clearly indicating that heparanase is a reliable prognostic factor for this malignancy and an attractive target for anticancer drug development.