Signif icance of Matrix Metalloproteinase-9 Expression in Human Papillary Thyroid Carcinomas

Objective 　To investigate the significance of matrixmetalloproteinase-9 expression in human papillary thyroid carcinomas (PTC) . Methods 　The expression of MMP-9 was detected immunohistochemically in 62 PTC and 28 lymph nodes with corresponding cancer metastasis. The association was analysed between the positive rate of MMP-9 and the clinicopathologic features of PTC. Results 　The positive rate of MMP-9 expression was 79. 0 % ( 49/ 62 ) and 100. 0 % (28/ 28) in primary PTC and metastatic lymph nodes respectively. The expression of MMP-9 was enhanced with the increase of the depth of invasion and lymph node metastasis. Conclusion 　The overexpression of MMP-9 was significantlycorrelated with invasion and lymph node metastasis of PTC.