Prognostic implications of Fas-ligand expression in nasopharyngeal carcinoma

Background. In nasopharyngeal carcinoma (NPC), Fas-ligand (Fas-L)-mediated apoptosis might contribute to the immune privilege of tumors. In some cancers, dysregulation of Fas-L protein in tumors might lead to disease progression. The purpose of this study was to evaluate the correlations between Fas-L expression and the clinical outcomes in patients with NPC. Methods. We recruited 78 patients with primary NPC, classified clinical stages according to the 1997 American Joint Committee on Cancer staging system, and assessed Fas-L with immunohistochemical methods. Results. Forty-one (53%) of 78 patients were Fas-L-positive. The prevalence was 0%, 57%, 58%, and 82% from stages I to IV, respectively (p < .001). Fas-L expression was associated with the N classification (p = .05) but not the T classification. Patients with positive Fas-L expression had a lower rate of disease-free survival and overall survival (p = .01 for all log-rank tests). Conclusion. Patients with NPC with Fas-L-positive tumors had higher clinical stages and lymph node metastasis at diagnosis and poorer disease-free survival and overall survival; therefore, Fas-L expression may be a potential biomarker of prognosis.