Study on the Expression of Matrix Metalloproteinases-9 in Benign and Malignant Thyroid Tissues

Objective:To investigate the expression of matrix metalloproteinases-9(MMP-9)in benign and malignant thyroid tissues and its clinical significance.Methods:The expression of MMP-9 in 50 thyroid cancers,45 adenoma and 20 adjacent noncancerous portion tissues were respectively studied with microwave-LSAB immunohistochemical methods.Results:The positive rate of MMP-9 in thyroid cancer was 64.0%,which was significantly higher than 37.8% in adenoma and 25.0% in adjacent noncancerous portion(P0.05).No correlation was observed between expression of MMP-9 and histological grading of thyroid cancer.The expression of MMP-9 in lymph node metastasis and grade Ⅲ-Ⅳ were both higher than that in negative cases and in gradeⅠ-Ⅱ(P0.05).The percentage of recurrence and death in MMP-9 positive cases were notably higher than that in negative cases(P0.05).Conclusion:The expression of MMP-9 can be regarded as a parameter for evaluating the degree of malignancy,biological behavior and prognosis of thyroid cancer.