High STAT4 Expression Indicates Better Disease-free Survival in Patients with Gastric Cancer

Background: The aim of this study was to investigate the significance of signal transducer and activator of transcription 4 (STAT4) expression and the correlation between STAT4 and interferon gamma (IFN-gamma) in patients with gastric cancer. Patients and Methods: Sixty-two patients who underwent gastrectomy for gastric cancer were enrolled in the study. STAT4 and IFNG mRNA expression was evaluated by quantitative real-time polymerase chain reaction (PCR). Immunohistochemistry was performed to examine CD8(+) T-cells, and STAT4 and IFN-gamma expression. Results: STAT4 mRNA expression was significantly correlated with IFNG mRNA expression (p<0.05). Regarding disease-free survival, there was a significant difference between the groups with high and low STAT4 expression (5-year disease-free survival: 77.8% and 56.4%, p<0.05). Univariate analysis revealed that tumor differentiation and STAT4 expression were significant factors for tumor recurrence. Conclusion: High expression of STAT4 in gastric cancer predicted a better clinical outcome. STAT4 might be a useful biomarker to identify patients at high risk of recurrence after gastrectomy.