NSCLC: does TKI resistance affect radiotherapy efficacy?

  • Zhao L & al.
  • Radiat Oncol
  • 31 Dec 2019

  • curated by Kelli Whitlock Burton
  • Univadis Clinical Summaries
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Takeaway

  • Intracranial PFS or OS did not differ significantly after whole-brain radiotherapy (WBRT) for brain metastases in NSCLC with or without resistance to epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs).
  • However, in a subgroup of patients with a Lung Cancer Using Molecular Markers Graded Prognostic Assessment (Lung-molGPA) score of 2.5-4, those with TKI resistance had worse intracranial PFS and OS than TKI-naive patients.

Why this matters

  • Whether EGFR-TKI resistance affects the efficacy of WBRT in patients with NSCLC with brain metastases is unknown.

Study design

  • 344 patients with EGFR-mutated NSCLC and multiple brain metastases who were TKI-naive (n=207) or TKI-resistant (n=137).
  • Funding: Wenzhou Science and Technology Bureau.

Key results

  • 57.8% of patients had a Lung-molGPA score of 0-2.
  • 42.2% had a score of 2.5-4.
  • Overall, median PFS and OS did not differ significantly between the TKI-naive and TKI-resistant groups.
  • In patients with Lung-molGPA 2.5-4, compared with the TKI-resistant group, TKI-naive patients had: 
    • Significantly longer median intracranial PFS (12.8 vs 10.1 months; P=.014).
    • Significantly longer median OS (23.3 vs 15.3 months; P=.005).
  • Results suggesting a benefit from undergoing WBRT before TKI treatment.

Limitations

  • Retrospective, single-center study.