TIGAR Is Correlated with Maximal Standardized Uptake Value on FDG-PET and Survival in Non-Small Cell Lung Cancer

OBJECTIVE: Evaluation of (18)F-FDG uptake value via PET is central to current methods of diagnosis and staging of non-small cell lung cancer (NSCLC) due to its ability to evaluate expression levels of key regulators associated with glucose metabolism in tumor cells. Tp53-induced glycolysis and apoptosis regulator (TIGAR) is an important P53-induced protein that can inhibit glycolysis; however, there have been few clinical studies on its mechanism. Here we have investigated the relationship between TIGAR expression and (18)F-FDG PET in tumors, along with its relationship with the clinical characteristics of NSCLC. METHODS: We analyzed SUV(max) in 79 patients with NSCLC through immunohistochemical staining of TIGAR and five other biological markers associated with tumor cell glycolysis, in order to evaluate the correlation between their expression and SUV(max). We also plotted Kaplan-Meier survival curves to assess TIGAR expression with the prognosis and survival of patients with NSCLC. RESULTS: The key findings were as follows: SUV(max) was negatively correlated with the expression of TIGAR (r = −0.31, p<0.01); TIGAR expression was correlated with tumor size (p = 0.01), histological type (p<0.01), differentiation degree (p<0.01) and lymph node metastasis(p<0.01) in patients with NSCLC; and the survival time of patients whose TIGAR was negatively expressed was significantly shorter than for those whose TIGAR was positively expressed (P = 0.023). CONCLUSIONS: The expression of TIGAR in primary tumors is significantly correlated with SUV(max), and low expression of TIGAR may predict a worse clinical outcome in patients with NSCLC.