The expression of metaloproteinases-2 and -9 is different according to the patterns of growth and invasion in squamous cell carcinoma of the penis

Squamous cell carcinoma (SCC) of the penis is characterized by different patterns of growth and local invasion. The matrix metalloproteinases (MMPs) is a family of proteolytic enzymes that are involved in the degradation of extracellular matrix to allow the migration of tumor cells. The present study examined whether the expression of MMP-2 and -9 is correlated with the patterns of tumor growth and invasion in penile SCC. The expression of MMP-2 and -9 was examined immunohistochemically in samples of 115 patients. The cases were divided in three groups according to the patterns of growth and invasion: group 1, exophytic growth and pushing pattern of invasion; group 2, endophytic growth and invasion in large sheets of cells; and group 3, endophytic growth and invasion in small group or isolated cells. Tumors with MMP-2 and -9 overexpression are deeply invasive and present an invasion pattern of small groups of cells. Also, expression of MMP-2 changed from membrane to cytoplasm in invasive tumors, maybe representing activation of MMP-2. These findings allow us to conclude that the less differentiated tumors, which are more invasive and with a pattern of invasion in small group of cells, are associated with the overexpression of MMPs.