Diverse role of MMP-2 and MMP-9 in the clinicopathological behavior of Hodgkin's lymphoma

This is the first study to describe the role of MMP-2 and MMP-9 in Hodgkin's disease. Strong MMP-2 expression correlated with a favorable prognosis, while MMP-9 expression showed a tendency toward an adverse outcome. MMP-9 expression correlated with B symptoms and decreased new vessel formation. MMP-2 expression was associated with the nodular sclerosis subtype, and its expression was most pronounced in the vicinity of sclerosis. Neither of the gelatinases nor the extent of neovascularization correlated with tumor stage, the occurence of bulky disease, or extranodal infiltrates. Together, these findings imply that the adverse role of MMP-9 may be associated with the controlling of immunological processes but not the invasion probabilities or neovascularization of the tumor. The favorable prognostic value of MMP-2 is surprising in view of the role of MMPs in solid tumors. This, however, may be linked to the basic biological differences of hematological malignancies vs. other tumors.