Prognostic significance of pyruvate kinase M2 expression in esophageal squamous cell carcinoma and its meta-analysis

BACKGROUND: Pyruvate kinase 2 (PKM2) is a key enzyme in the glycolysis pathway and has been reported to be associated with the development of esophageal squamous cell carcinoma (ESCC). However, the prognostic value of PKM2 in ESCC remains undetermined. METHODS: This study aimed to investigate the clinicopathological significance of PKM2 expression in ESCC. A comprehensive and systematic literature search was conducted using the PubMed, Embase, Medline, and Cochrane library databases. The quality of studies and potential for bias were appraised, and meta-analysis was performed to assess the prognostic impact of PKM2 on overall survival (OS). RESULTS: A total of 5 studies with 781 participants were eligible and enrolled. Patients with high PKM2 expression were associated with poor prognosis in ESCC [hazard ratio (HR) =1.72, 95% confidence interval (CI): 1.41–2.09; P<0.01]. Furthermore, upregulated PKM2 was significantly associated with lymph node metastasis [odds ratio (OR) =2.38, 95% CI: 1.68–3.35; P<0.01], clinical stage (OR =3.29, 95% CI: 2.27–4.77; P<0.01), and tumor (T) classification (OR =2.92, 95% CI: 2.05–4.16, P<0.01). DISCUSSION: High PKM2 expression denotes worse OS in ESCC patients, and correlates with the lymph node metastasis, clinical stage, and T classification. However, further studies are warranted to assess how PKM2 can be implemented as a reliable staging element in clinical practice and whether it could provide a new target for therapeutic intervention.