TIGAR is correlated with maximal standardized uptake value on FDG-PET and survival in non-small cell lung cancer

Objectives Evaluation of 18F-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 18F-FDG PET in tumors, along with its relationship with the clinical characteristics of NSCLC.

Methods We analyzed SUVmax 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 SUVmax. 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: SUVmax 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 SUVmax, and low expression of TIGAR may predict a worse clinical outcome in patients with NSCLC.

Research Support This work was supported by grants from the National Natural Science Foundation of China (Nos. 30830038, 30970842, and 81071180), the Major State Basic Research Development Program of China (973 Program) (No. 2012CB932604), and the New Drug Discovery Project (No. 2012ZX09506-001-005).