Inverse relationships between the expression of MMP-7 and MMP-11 and predictors of poor prognosis of papillary thyroid carcinoma

AIMS: Matrix metalloproteinases (MMPs) have various functions that play roles in carcinoma development. In this study, we investigated the expression of two representative MMPs, MMP-7 and MMP-11, in papillary thyroid carcinomas. METHODS: We immunohistochemically investigated the expression of these MMPs in 196 cases of papillary carcinoma. RESULTS: A high level of MMP-7 expression was observed in 56 cases (28.3%). The expression level was significantly decreased in cases showing large tumour, N positivity, large pT and poor differentiation. MMP-11 expression was high in 119 cases (60.1%). The expression level was inversely related to tumour size, N factor, pT factor, pN factor, extrathyroid extension, and poor differentiation. CONCLUSIONS: In contrast to other MMPs, MMP-7 and MMP-11 are inversely linked to aggressive characteristics of papillary thyroid carcinoma and their down-regulations may even be a marker of poor prognosis in patients.