Circulating levels of Galectin 9 are a potential biomarker predictive of overall survival in patients with advanced Non-Small-Cell Lung Cancer

Background: The immune system is recognized to have therapeutic potential to destroy cancer cells. T-cell immunoglobulin mucin domain-3 (sTIM-3) and its ligand galectin 9 (GAL9) cause suppression of cytokine production, cell cycle arrest, and cell death. Then, soluble levels of TIM-3 and GAL-9 may have prognostic implications in non-small-cell lung cancer (NSCLC) in non-smoker patients. Methods: This prospective cohort study, including 49 NSCLC patients with an age median of 65 years, evaluated the soluble levels of sTIM-3 and sGAL9 by enzyme-linked immunosorbent assay. Results: Low levels of sGAL9 in smokers compared to non-smoker NSCLC patients (P<0.0001). Overall survival (OS) analysis showed a low median survival of 10.5 months in smokers NSCLC patients compared to non-smokers (Log-Rank test; P = 0.009). The area under the curve (AUC) value of the Receiver Operating Characteristic (ROC) curve was 0.8497, suggesting that sGAL9 could be an OS biomarker for advanced NSCLC, being the cut-off value of serum of 1,694 pg/mL for sGAL9. Low sGAL9 levels NSCLC patients’ group had significantly shorter OS than those in the high sGAL9 levels (Log-Rank test; P = 0.02). Conclusion: This study indicated the accuracy of sGAL9 as a potential biomarker predictive of OS in advanced NSCLC.