Prognostic and clinicopathological value of myeloid-derived suppressor cells in lung cancer: a comprehensive systematic review and meta-analysis.

[INTRODUCTION] Lung cancer remains the leading cause of cancer-related mortality, and reliable prognostic biomarkers are needed. The prognostic significance of myeloid-derived suppressor cells (MDSCs) in lung cancer is the aim of the current systematic review and meta-analysis.

[METHODS] A systematic search was conducted in PubMed, Scopus, Web of Science, and Embase, and eligible studies included patients with lung cancer reporting survival/progression outcomes by MDSCs level. Study quality was assessed using the Joanna Briggs Institute (JBI) checklist. The Comprehensive Meta-Analysis (CMA) software version 3 was used to estimate pooled hazard ratios (HRs) with 95% confidence intervals (CIs).

[RESULTS] Twenty-five studies (1,679 patients) were included. Elevated baseline monocytic MDSCs (M-MDSCs) were significantly associated with worse overall survival (OS) in non-small cell lung cancer (NSCLC) (HR = 1.89, 95% CI: 1.39-2.59) and small cell lung cancer (SCLC) (HR = 2.72, 95% CI: 1.62-4.59), and with shorter progression/recurrence-free survival in NSCLC (HR = 1.86, 95% CI: 1.44-2.40). Associations for polymorphonuclear MDSCs (PMN-MDSCs) were weaker and inconsistent, showing significance only in HR for OS based on univariable data (HR = 1.76, 95% CI: 1.32-2.35).

[CONCLUSIONS] High M-MDSCs predict adverse outcomes in lung cancer, supporting their role as prognostic biomarkers and potential therapeutic targets.

[REGISTRATION] PROSPERO (CRD420251026405).