Increased expression of matrix metalloproteinase-2 and tissue inhibitor of metalloproteinase-2 is correlated with poor prognostic variables in patients with thymic epithelial tumors.

Background: A distinction between noninvasive, invasive, and metastatic thymoma on the basis of the cytologic features is difficult. The current study investigated whether the expression of MMP and TIMP was correlated with tumor invasiveness and prognosis in patients with thymoma.

Methods: Tumor tissue samples were obtained from 42 patients with thymic epithelial tumors between 1974 and 2001 at Tokushima University Hospital.