Matrix metalloproteinase-2 (MMP-2) immunoreactive protein - A new prognostic marker in uveal melanoma?

Uveal melanoma is the most common primary intraocular tumour, Once haematog enous metastasis has occurred, there is no cure for the disease and there i s an obvious need for new biological prognostic markers to estimate the ris k of metastasis. In this study, the expression of matrix metalloproteinase- 2 (MMP-2) was characterized immunohistochemically in 29 human uveal melanom as, Enzyme-linked immunoassays and gelatin zymographies were assessed in or der to quantify the expression of gelatinases A and B, as well as the tissu e inhibitor of metalloproteinases (TIMPs), in the vitreous body. A total of 49 per cent of the ureal melanomas displayed a positive immunoreaction for MMP-2 in melanoma cells, the epithelioid cells showing the most frequent s taining. There was no correlation between the positivity of MMP-2 staining and the size of the primary tumour, gender or age. The expression of MMP-2 Has associated sith a dismal prognosis: the 5-year overall survival rate fo r MMP-2-positive cases was significantly inferior to that of the MMP-2 nega tive cases, 49 per cent vs. 86 per cent, respectively (p=0.02). A patient g roup at high risk of metastatic disease was identified; only 38 per cent of patients with a MMP-2-positive non-spindle cell uveal melanoma survived fo r 5 years, The analyses of MMPs or TIMPs in the vitreous body had no progno stic value. Positive immunostaining for MMP-2 was observed in the retinal p igment epithelium. corneal epithelium, and fibroblasts in the ciliary body and choroid, It is concluded that immunohistochemical analysis of MMP-2 may help to predict a risk of metastasis in uveal melanoma, Copyright (C) 1999 John Wiley & Sons, Ltd.