Matrix metalloproteinase-2 (MMP-2) and MMP-9 expression in invasive ductal carcinoma of the breast.

Matrix metalloproteinase-2 (MMP-2) and MMP-9 are gelatinases that play a role in the invasion and metastasis of cancer through the destruction of the basal membrane and extracellular matrix. In this study, we investigated the immunohistochemical expression of MMP-2 and MMP-9 and the correlation between the expression levels and prognostic clinicopathological parameters in 140 patients with invasive ductal carcinoma (IDC). The staining scores for MMP-9 were negative in 21 cases (15%), mild in 27 cases (19%), and strong in 92 cases (66%). MMP-9 expression was increased in high-grade (p=0.001), triple-negative (ER, PR, HER2 negative) (p=0.006), and ER-negative tumors (p=0.004) and tumors with distant metastases (p=0.028). MMP-9 expression was increased in cases with HER2 over-expression/amplification, but no statistically significant difference was found (p=0.215). No correlation was found between lymph node metastasis or tumor size and MMP-9 expression (p=0.492 and p=0.448, respectively). The staining scores for MMP-2 in 140 cases were negative in 10 cases (7%), mild in 25 cases (18%), and strong in 105 cases (75%). MMP-2 expression was increased in ER-negative and high-grade tumors in the lymph node-negative group (p=0.025 and 0.026, respectively). High MMP-9 expression was associated with a shorter disease-free survival and overall survival times (p=0.042 and p=0.046, respectively). In conclusion, increased MMP-9 expression is related to poor prognostic clinicopathological factors in IDC, and hence, it can be utilized as a supplementary prognostic marker. The role of MMP-2 expression in the prognosis of IDC is rather limited.