Significance of plasminogen-activation system in the formation of macroscopic types and invasion in esophageal carcinoma

BACKGROUND: The roles of urokinase-type plasminogen activator (uPA) and plasminogen activator inhibitor-1 (PAI-1) in the formation of macroscopic types and invasion were investigated. MATERIALS AND METHODS: A total of 40 surgically-resected esophageal carcinoma tissues were immunohistochemically stained, and the expression of uPA, PAI-1 and the uPA/PAI-1 ratio, were evaluated. RESULTS: The expression of uPA was significantly stronger in the macroscopically infiltrative type (n = 20: p = 0.0027), whereas PAI-1 was significantly stronger in the localized type (n = 20: p = 0.0005). The uPA/PAI-1 ratio was significantly higher in the infiltrative type (p < 0.0001). A significant correlation was found between the U/P ratio and the depth of tumor invasion (r = 0.511, p = 0.0014). Analysis of tumors of uniform size (4.0-6.0 cm in length), showed that the depth of invasion was significantly greater in the infiltrative type (p = 0.0038). CONCLUSION: The results demonstrated that uPA and PAI-1 play important roles in invasion and formation of macroscopic types of esophageal carcinoma.