Urokinase-type plasminogen activator receptor expression in adenoid cystic carcinoma of the skull base.

BACKGROUND Head and neck adenoid cystic carcinoma (ACC) is a malignancy of the salivary and lacrimal glands with a variable growth pattern and propensity for perineural spread. Involvement of the skull base indicates a poor prognosis. Despite surgical resection and adjuvant radiotherapy, tumor recurrence and metastases are common. The urokinase-type plasminogen activator and its receptor (uPAR) have an important role in tumor invasion and metastasis. The expression of uPAR is predictive of poor outcomes in many tumors. This study examines the expression of human uPAR in ACCs involving the skull base. OBJECTIVES To determine uPAR expression in ACCs of the skull base by immunohistochemical analysis and compare expression with tumor histologic findings and clinical outcomes. STUDY DESIGN Analysis of uPAR in archival ACC specimens and a retrospective medical chart review. SETTING Multidisciplinary cranial base program at a university medical center with tertiary referral pattern. RESULTS Ten (83%) of 12 tumors stained positive for uPAR. Three of 3 patients who died of ACC and 6 of 6 patients alive with disease expressed uPAR. Only 1 of 3 patients free of disease was uPAR positive. CONCLUSIONS In most patients with ACC of the skull base, uPAR was expressed. Its expression seems to be a negative prognostic factor. However, the small study sample limits our observations. Additional study of uPAR expression in ACC at other anatomic sites is required.