Background & objective: Epidermal growth factor receptor (EGFR) is overexpressed in many tumors, and is correlated to poor prognosis. However, the prognostic value of EGFR expression in nasopharyngeal carcinoma (NPC) is controversial. This study was to investigate the expression of EGFR and its phosphorylated form (pEGFR) in NPC, and explore their correlations to the prognosis.
Methods: NPC samples were obtained from 110 NPC patients treated at Cancer Center of Sun Yat-sen University from Jan. 1999 to Dec. 1999. The expression of EGFR and pEGFR in 110 specimens of NPC and 20 specimens of normal nasopharyngeal tissues were detected by immunohistochemistry. The correlations of EGFR and pEGFR expression to clinical characteristics and prognosis of NPC were analyzed by univariate and multivariate analyses.
Results: The positive rates of EGFR and pEGFR were significantly higher in NPC than in normal tissues (100% vs. 10.0%, 60.0% vs. 15.0%, both P<0.001). High expression rate of EGFR was significantly higher in stage T3-4 tumors than in stage T1-2 tumors (63.6% vs. 43.2%, P=0.034), but it had no relationship with other clinical parameters. The 5-year metastasis-free survival rate was significantly lower in the patients with high pEGFR expression than in those with low pEGFR expression (72.2% vs. 91.0%, P=0.012). However, multivariate analysis revealed that pEGFR expression was not an independent prognostic factor for metastasis-free survival of NPC patients.
Conclusion: Phosphorylation of EGFR is related with metastasis-free survival of NPC patients, suggesting an important role of activation of EGFR in the dissemination of NPC.