Clinical evidence for correlation of insufficient tissue oxygen supply (hypoxia) and tumor-associated proteolysis in squamous cell carcinoma of the head and neck.

Hypoxic tumors of patients with squamous cell carcinoma of the head and neck show a consistent trend towards poor treatment outcome. We now report that tumor hypoxia in these patients is correlated with elevated antigen content of the tumor-associated serine protease uPA (urokinase-type plasminogen activator), a marker of tumor cell invasion and metastasis.