Clinical significance of MMP-9 expression in human gastric cancer

Objective To evaluate the relationship between matrix metalloproteinase - 9(MMP-9) expression and invasion, metastasis and prognosis of gastric cancer. Methods The expression of MMP-9 was detected immunohistochemically in 20 normal gastric mucosa, 20 dysplastic gastric mucosa, 108 gastric cancers tissues and 47 lymph nodes with corresponding cancer metastasis. Results The positive rate of MMP-9 expression was 20.0% (4/20) and 70. 0% (14/20) in normal and dysplastic mucosa respectively, and their positive expressions were weak. The positive tale of MMP-9 immunoreachvity was 88.9% (96/108) and 100.0% (47/47) in primary gastric cancers and metastatic lymph nodes respectively, and the positive rate of MMP-9 in gastric cancer was significantly higher than that in normal and dysplastic mucosa (P0.05). The staining intensity of MMP-9 was correlated with Ming's tumor growth pattern, the UICC TNM classification, lymphatic and venous vessel invasion and distant metastasis(P 0.05). The patients with MMP-9 strong positive tumor had low 5-year survival rate(P 0.05). Conclusion The MMP-9 expression is significantly correlated with invasion, metastasis and prognosis of gastric cancer.