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.