Comparison of the prognostic value of matrix metalloproteinases 2 and 9 in cutaneous melanoma. 
Previously, gelatinases matrix metalloproteinase (MMP)-2 and MMP-9 have been shown to be involved in melanoma invasion and progression.  Also, overexpression of MMP-2 has been suggested to be linked to hematogenous metastasis in melanoma.  This study was conducted to study the prognostic value of MMP-2 and MMP-9 in human melanoma.  The expression of MMP-2 and MMP-9 immunoreactive protein was evaluated in 157 cases of primary melanomas.  An immunohistochemical analysis using specific monoclonal antibodies for MMP-2 and MMP-9 on paraffin-embedded tissues was performed, and the immunostaining results were compared with the clinical course of melanoma.  Overexpression of MMP-2 (>20% of malignant cells positive) was an independent prognostic marker for melanoma related death, with odds ratio of 2.6 (95% confidence interval, 1.32-5.07).  The 10-year disease-specific survival rate was only 51% in patients with overexpression of MMP-2 protein compared with 79% in patients with a primary melanoma with low expression for MMP-2 (P = .001).  Interestingly, male patients with a melanoma with overexpression of MMP-2 showed a 10-year disease-specific survival of only 41% compared with 77% in other male patients (P = .003).  It is notable that the immunoreactive protein for MMP-9 in primary melanoma was not found to be of any prognostic importance.  In the future, MMP-2 could be acknowledged as a new prognostic factor in melanoma.  MMP-9, on the other hand, was not associated with the clinical course of melanoma.  Based on the current data, MMP-2 could be evaluated as an inclusion factor for adjuvant studies especially in male melanoma patients.