Background & objective: Endothelin A receptor (ET(A)R) activation contributes to tumor growth and metastasis, including cell proliferation, cell death, angiogenesis, and metastatic spread. In this study, we evaluated correlation of ET(A)R expression to clinical features of nasopharyngeal carcinoma (NPC), and explored its correlation to prognosis.
Methods: Expression of ET(A)R in 153 specimens of NPC was detected by SABC immunohistochemistry.
Results: Positive rate of ET(A)R was 73.9% in the 153 NPC specimens. No correlation was found between ET(A)R expression and gender, age, T stage, N stage, and TNM stage of the patients. The 3-year overall survival rate, relapse-free survival rate, and distant metastasis-free survival rate were significantly higher in ET(A)R-negative patients than in ET(AR-positive patients (87.5% vs. 73.2%, P = 0.029; 80.0% vs. 57.3%, P = 0.009; and 89.9% vs. 70.4%, P = 0.012), except for local relapse-free survival rate (86.9% vs. 80.2%, P = 0.228). Cox multivariate analysis showed that ET(A)R expression, gender, age, T stage, and N stage were independent prognostic factors, which affected overall survival, relapse-free survival, and distant metastasis.
Conclusion: ET(A)R expression is an important distant metastasis-related risk factor for patients with NPC; its overexpression indicates poor prognosis.