Urokinase-type plasminogen activator, plasminogen activator inhibitor type 1 and cathepsin D: analysis of their prognostic significance in squamous cell carcinoma of the head and neck.

BACKGROUND The aim of the study was to evaluate the prognostic significance of tumour and serum concentrations of urokinase-type plasminogen activator (uPA), its type 1 inhibitor (PAI-1) and cathepsin D (Cath D) in patients with squamous cell carcinoma of the head and neck (SCCHN). PATIENTS AND METHODS Determinations of uPA and PAI-1 were made using enzyme-linked immunosorbent assays in tumour and serum samples of 47 and 32/47 patients, respectively. For the determination of tumour (94 patients) and serum (34/94 patients) Cath D concentrations, an immunoradiometric assay was used. RESULTS In an univariate survival analysis, the risk of disease recurrence and SCCHN-related death was significantly higher in the patients with high uPA (P = 0.046, P = 0.010) tumours, compared to those with low uPA tumours. In addition, the high serum levels of uPA correlated positively with the rate of relapse (P = 0.007), but not with the mortality rate (P = 0.200). There was no statistically significant difference between low and high PAI-1 groups, regarding either tumour or serum concentration of the inhibitor, and between low and high Cath D tumours. Low Cath D serum levels appeared to be related to longer disease-free interval (P = 0.055), but not to disease-specific survival (P = 0.120). CONCLUSIONS The tumour levels of uPA, as well as serum levels of uPA and Cath D could potentially predict the survival probability of patients with SCCHN. However, the strength of this association remains to be investigated on a larger and more homogeneous group of patients.