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.