Correlation of GST-pi and PCNA expression to prognosis of advanced maxillary sinus squamous cell carcinoma

BACKGROUND OBJECTIVE: Tumor markers which relate to cell proliferation and metabolism have seldom been studied in maxillary sinus cancer. This study was conducted to identify the correlation of glutathione S-transferase π (GST-π) and proliferating cell nuclear antigen (PCNA) expression to prognosis of advanced maxillary sinus squamous cell carcinoma (SCC). METHODS: The expression of GST-π and PCNA in 54 specimens of maxillary sinus SCC, 29 specimens of benign maxillary tumor, and 20 specimens of normal nasal mucosa was detected by immunohistochemistry. The correlation of GST-π and PCNA expression to prognosis of advanced maxillary sinus SCC was analyzed by Kaplan-Meier method. The prognosis was analyzed by Cox multivariate model. RESULTS: The overexpression rates of GST-π and PCNA were significantly higher in maxillary sinus SCC than in benign maxillary tumor and normal nasal mucosa (74.1% vs. 89.6% and 15.0%, P0.01; 79.6% vs. 3.4% and 0, P0.01). The 5-year survival rate was significantly higher in advanced maxillary sinus SCC patients with high expression of GST-π than in the patients with low expression of GST-π (34.5% vs. 21.2%, P=0.025); the difference between the patients with high and low expression of PCNA was not significant (18.0% vs. 27.0%, P=0.890). The expression of GST-π was an independent prognostic factor of advanced maxillary sinus SCC (P=0.039, odds ratio1). CONCLUSION: The overexpression of GST-π is an independent prognostic factor of advanced maxillary sinus SCC, but that of PCNA isn't.