Circulating levels of galectin‐9 are a potential biomarker of survival in advanced non‐small‐cell lung cancer

Abstract Background The immune system is recognized to have therapeutic potential to destroy cancer cells. Soluble T‐cell immunoglobulin mucin domain‐3 (sTIM‐3) and its ligand galectin 9 (Gal‐9) cause suppression of cytokine production, cell cycle arrest and cell death. sTIM‐3 and Gal‐9 levels may have prognostic implications in non‐small‐cell lung cancer (NSCLC) patients. Methods This prospective cohort study was performed at Instituto de Medicina Integral Prof. Fernando Figueira, Recife, Pernambuco, Brazil. Fifty‐eight patients were diagnosed with advanced NSCLC from January 2019 to January 2020. Results The age median was of 64.0 years. Soluble galectin‐9 (sGal‐9) levels in the smokers compared to nonsmoker patients ( p < 0.0001). By using the receiver operating characteristic curve, we found that a baseline of 1694 pg/mL (cutoff). sGAL9 with specificity (72.2%), sensitivity (83.2%) and area under the curve = 0.8497 ( p < 0.0004). Until 18.2 months, 46.8% and 72.9% were alive in the sGAL9 low and sGAL9 high groups, respectively (log‐rank test; p = 0.02). The median survival was 15.9 months for sGAL9 low (≤1694 pg/mL). Conclusion This study indicated an association of tobacco with the release of circulating sGal‐9 levels and the accuracy of sGal‐9 as a potential biomarker predictive of survival time in advanced NSCLC patients. Furthermore, sGal‐9 has may be a potential therapeutic target in the advanced NSCLC.