Circulating Immune Markers for Prognostic Evaluation in Postoperative Lung Cancer Patients

Non-small cell lung cancer (NSCLC) remains the leading cause of cancer-related mortality worldwide, with surgical resection serving as the curative approach for early to intermediate stages. However, postoperative recurrence rates are high in stages IB (with high-risk features such as tumor >4 cm, poor differentiation, visceral pleural invasion, vascular invasion, or wedge resection) to IIIB, necessitating improved prognostic tools beyond TNM staging to optimize adjuvant therapies like chemotherapy or immunotherapy.

This study investigates peripheral blood immune markers as non-invasive prognostic indicators. Antigen-specific effector T cells (ETASTs) are identified via multiparametric flow cytometry, co-expressing CD137 (a T-cell activation marker) and IFN-γ (an effector cytokine) following ex vivo stimulation with tumor-associated antigens. The effector T cell to regulatory T cell ratio (Teff/Treg) reflects systemic immune homeostasis, with imbalances promoting tumor immune evasion.

Blood samples (approximately 10 mL) are collected preoperatively via venipuncture and processed within 4 hours. Peripheral blood mononuclear cells (PBMCs) are isolated using Ficoll density gradient centrifugation. For ETAST detection, PBMCs undergo stimulation with a peptide pool of common NSCLC antigens (e.g., NY-ESO-1, MAGE-A3) for 6 hours in the presence of brefeldin A, followed by intracellular staining and analysis on a BD FACSCanto II flow cytometer. Teff cells are defined as CD4+ or CD8+ T cells expressing IFN-γ, TNF-α, or IL-2; Treg cells as CD4+CD25+FoxP3+. Data acquisition targets at least 100,000 events per sample, with analysis using FlowJo software.

Follow-up includes clinical assessments every 3 months for the first 2 years, then every 6 months up to 3 years, monitoring recurrence via CT scans, PET-CT if indicated, and survival endpoints. Exploratory analyses may incorporate next-generation sequencing for driver mutations (e.g., EGFR, ALK) from tumor tissue to correlate with immune profiles.

Ethical considerations prioritize participant safety, with all procedures approved by the institutional review board. Data are de-identified and stored securely, complying with GCP standards.

Inclusion criteria

• Age 18 to 80 years.
• Diagnosed with primary non-small cell lung cancer (NSCLC) and scheduled to undergo curative lung resection at the Department of Thoracic Surgery of our institution.
• Postoperative pathological stage is IB (with tumor size >4cm or high-risk factors: poor differentiation, vascular invasion, visceral pleural invasion, sub-lobar resection, etc.), IIA, IIB, or IIIB (according to the AJCC 8th edition).
• ECOG performance status of 0 or 1.
• Voluntarily signs the informed consent form.

Exclusion criteria

• Received any neoadjuvant therapy prior to surgery.
• History of other active malignancies.
• Diagnosed with severe autoimmune diseases, active infections, or immunodeficiency disorders.
• Presence of severe cardiac, hepatic, or renal dysfunction.
• Pregnant or lactating women.