Pyruvate kinase M2 is a marker of poor prognosis in lung adenocarcinoma but not lung squamous cell carcinoma

BACKGROUND: To explore the pyruvate kinase M2 (PKM2) expression profile as a prognostic marker of lung adenocarcinoma (LUAD) as well as lung squamous cell carcinoma (LUSC). METHODS: Retrospective bioinformatics analysis of data from the Cancer Genome Atlas-Lung Cancer dataset and the Human Protein Atlas was performed. PKM2 mRNA expression was monitored using the Kaplan-Meier Plotter online database. GraphPad Prism 6.0 and the SPSS 19.0 software package were used for statistical analysis. RESULTS: PKM2 expression was found to be significantly higher in both LUAD and LUSC than in normal controls. Although increased PKM2 expression in LUAD was correlated with poor overall survival (OS) [hazard ratio (HR): 2.128; 95% CI: 1.754–3.653; P<0.001], recurrence-free survival (RFS) (HR: 1.524; 95% CI: 1.069–2.499; P=0.0237), and progression-free survival (PFS) (HR: 2.18; 95% CI: 1.58–3; P<0.001), no such associations were found in LUSC. CONCLUSIONS: PKM2 is a potential prognostic biomarker for LUAD but not for LUSC.