Relationship between head and neck squamous cell carcinomas and fibrinolytic factors. Immunohistological study.

: Localization of t-PA, u-PA, PAI-1, PI and TGF-beta within tumors was examined immunohistologically in 31 patients with squamous cell carcinoma (SCC) of the head and neck, and correlations between the localization of these factors and local cancer infiltration, tumor size or cervical lymph node metastasis were investigated. The results revealed that u-PA, PAI-1 and PI tend to stain more intensely in infiltrating tumors than in peripheral connective tissue or normal epithelium, whereas neither t-PA nor TGF-beta showed any such tendency. Not all of these fibrinolytic factors participated in lymph node metastases or influenced tumor size in head and neck SCCs. These results suggest a disorder of fibrinolytic systems in carcinoma cells and that u-PA plays a part in the infiltration of head and neck SCCs by degenerating connective tissue.