Expression of matrix metalloproteinase -9 and its significance in meningioma recurrence and regrowth

Objective To investigate the expression of matrix metalloproteinase-9 (MMP-9) and determine the biologic significance of MMP-9 in the meningioma recurrence and regrowth after surgery. Methods The expression level of MMP-9 were examined by immunohistochemistry (Envision method) in 74 patients with meningioma, including 30 with primary meningioma without recurrence (control), and 44 with meningioma recurrence and regrowth after surgery (71 samples, experimental). The relation between recurrence-free survival (RFS) and the expression of MMP-9 in different grades of meningioma with different operation frequency and resection degree was analyzed in these 101 samples. Results The mean expression of MMP-9 in the experimental group was significantly higher as compared with that in the control group (P<0.05); increased expression of MMP-9 was found following the increase of operation frequency in the experimental group; no obviously decreased expression of MMP-9 was found following the increase of recession degree in the experimental group, but the expression of MMP-9 in patients with grade II meningioma was significantly increased than that in patients with grade I meningioma and the RFS was statistically decreased (P<0.05). Conclusion MMP-9 may be involved in recurrence and regrowth of grade II meningioma, and increased expression of MMP-9 can be considered as an indicator for a high risk of recurrence and regrowth of meningioma. Key words: Meningioma;  Recurrence;  Regrowth;  MMP-9