Circulating Tumor DNA (ctDNA) Analysis Refines Consolidation Immunotherapy in Limited-Stage Small Cell Lung Cancer (LS-SCLC)

Strategic Insights -

A new study published at the International Association for the Study of Lung Cancer 2025 World Conference on Lung Cancer (WCLC) explores the use of circulating tumor DNA (ctDNA) to personalize consolidation immunotherapy in patients with limited-stage small cell lung cancer (LS-SCLC). The research, led by scientists at the National Cancer Center of China, demonstrates that early ctDNA detection after induction chemotherapy can identify patients who are more likely to benefit from consolidation immunotherapy. The study found that consolidation immune checkpoint inhibitors (ICIs) improved overall survival compared to chemoradiotherapy (CCRT) alone in patients with LS-SCLC.

Key Takeaways:

  • Consolidation ICI improved overall survival vs. CCRT alone, with a hazard ratio (HR) of 0.41 and p-value = 0.031.
  • Patients who were ctDNA-positive at post-induction had significantly better progression-free survival (PFS) and overall survival (OS) with ICI compared to CCRT alone.
  • ctDNA-negative patients did not show added benefit from ICI.
  • Maintaining ctDNA negativity during immunotherapy was associated with better prognosis.
  • ctDNA at post-induction (t1) was more predictive of treatment response than ctDNA post-radiotherapy (t2).
  • The study used next-generation sequencing (NGS) with a 139-gene lung cancer panel to assess ctDNA at ultra-deep coverage (30,000Èù).

Statistics:

  • 177 patients with LS-SCLC participated in the study.
  • 77 patients received consolidation immune checkpoint inhibitors (ICIs).
  • 100 patients received chemoradiotherapy (CCRT) alone.
  • The median overall survival was 24.8 months for patients treated with CTI vs. 12.5 months for CCRT alone (log-rank test, p=0.0001).

Sources:

  • International Association for the Study of Lung Cancer (IASLC). (2025). Circulating tumor DNA (ctDNA) analysis refines consolidation immunotherapy in limited-stage small cell lung cancer (LS-SCLC). Presentation at the 2025 World Conference on Lung Cancer (WCLC).
  • International Association for the Study of Lung Cancer (IASLC). About us. Retrieved from
  • International Association for the Study of Lung Cancer (IASLC). About the WCLC. Retrieved from