Expression patterns of stromal MMP-2 and tumoural MMP-2 and -9 are significant prognostic factors in invasive ductal carcinoma of the breast

Matrix metalloproteinases (MMPs) are matrix-degrading enzymes that play a pivotal role in aggressive behaviours, such as rapid tumour growth, invasion, and metastasis, of several types of solid tumours. In particular, stromal MMP-2 plays important roles in the progression of malignant tumours, but most clinical studies have focused on tumoural MMP-2 and -9 expression, and not stromal MMP-2 expression. One hundred and seventy-seven cases diagnosed as invasive ductal carcinoma of the breast between 2000 and 2005 were included in this study. Expressions of tumoural MMP-2 and -9 and stromal MMP-2 were analysed by immunostaining on a tissue microarray. Subsequently, the associations between those results and various clinicopathological parameters were evaluated. Stromal MMP-2 expression correlated significantly with clinicopathological parameters such as advanced T category, larger tumour size, high histological grade, tumour necrosis, ER- and PR-negative, and HER-2-positive (all p < 0.05). In univariate and multivariate analyses, overall survival was linked with stromal MMP-2 expression as well as dual expression of stromal MMP-2 and tumoural MMP-2 and -9 (all p < 0.05). Stromal MMP-2 expression may play a crucial role in predicting aggressive clinical behaviour in breast cancer patients.