Prognostic value analysis of urokinase-type plasminogen activator receptor in oral squamous cell carcinoma: an immunohistochemical study

In a retrospective study, a cohort of 189 OSCC patients was investigated for uPAR expression and its cellular localization by immunohistochemistry. As standard controls, 8 normal oral mucosal tissues free of malignancy, obtained from patients with no evidence or history of oral cavity tumours, were similarly investigated. After grouping for uPAR expression, OSCCs were statistically analyzed for the variables age, gender, histological grading (G), tumour size, recurrence, TNM staging and overall survival rate.In our immunohistochemical study, 74 cases (39.1%) of OSCC showed a mostly cytoplasmic positivity for uPAR, whereas 115 were negative. uPAR expression correlated with tumour differentiation grade and prognosis: percentage of positive cases was the greatest in G3 (70.4%) and patients positives for uPAR expression had an expectation of life lower than those for uPAR negatives.The results obtained in this study suggest a role of uPAR as a potential biomarker useful to identify higher risk subgroups of OSCC patients.Oral squamous cell carcinoma (OSCC) is one of the most common cancers, with a world incidence of more than 350 000 new cases per year [1]. In spite of improved therapeutic procedures, the mortality rate for this neoplasia has not changed appreciably in the Western world for over 20 years: the 5-year overall survival does not exceed 55% which is mainly caused by locally aggressive tumour phenotypes. At the moment, the most important prognostic factor for OSCC is efficacy of surgical treatment which consists in "complete" excision of the primary lesions and includes intra-operative histopathological examination of peri-tumoral tissues to confirm the presence of tumour-free excision margins. Nevertheless, within 24 months, up to 50% of the cases have relapse and/or metastasis, the possible explanations being inappropriate histopathological evaluation or the presence of "occult" cells that are undetectable by means of the currently used diagnostic procedures