[Immunohistological study of fibrinolytic factors of head and neck squamous cell carcinomas].

We investigated immunohistochemically the localization of urokinase-type plasminogen activator (u-PA), tissue-type plasminogen activator (t-PA), plasminogen activator inhibitor-1 (PAI-1), plasmin inhibitor (PI), and transforming growth factor-beta (TGA-beta) in tissue sections to examine the relationships between their localization and local invasiveness, tumor size and cervical lymph node metastasis of head and neck squamous cell carcinomas (SCCs). In invasive carcinomas, u-PA, PAI-1 and PI were stained stronger in carcinoma cells than in surrounding connective tissues or normal epithelial cells. However, no relationship was found between cell invasiveness and the localization of t-PA and TGF-beta in invasive SCCs. The expression of these factors was not related to cervical lymph node metastasis or the size of head and neck SCCs. These results suggest a disorder of the fibrinolytic systems of carcinoma cells, and that u-PA play a part in the invasion of head and neck SCCs by degenerating connective tissue.