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Comparison of uncommon EGFR exon 21 L858R compound mutations with single mutation

Liang Peng1, Zhigang Song2, Shunchang Jiao1

  • 1Department of Oncology, Chinese PLA General Hospital, Chinese PLA Medical School, Beijing, People's Republic of China.

Oncotargets and Therapy
|May 12, 2015
PubMed

Insights

Epidermal growth factor receptor (EGFR) compound mutations in non-small-cell lung cancer show similar responses to EGFR tyrosine kinase inhibitors (TKIs) compared to single mutations. Outcomes for patients with compound or single L858R mutations were also comparable.

Area of Science:

  • Oncology
  • Molecular Biology
  • Pharmacogenomics

Background:

  • Non-small-cell lung cancer (NSCLC) with epidermal growth factor receptor (EGFR) mutations often responds to EGFR tyrosine kinase inhibitors (TKIs).
  • The clinical significance and treatment response of compound EGFR mutations, particularly uncommon ones like exon 21 L858R, remain largely uncharacterized.
  • Understanding these mutations is crucial for optimizing targeted therapy in NSCLC.

Purpose of the Study:

  • To compare the treatment response and prognostic role of uncommon EGFR exon 21 L858R compound mutations versus single L858R mutations in NSCLC patients receiving EGFR TKIs.
  • To characterize the clinical features of EGFR compound mutations.
  • To evaluate the impact of compound versus single L858R mutations on treatment outcomes.

Main Methods:

  • Retrospective screening of 799 NSCLC patients for EGFR mutations.
  • Identification and characterization of patients with EGFR exon 21 L858R compound mutations and matched single L858R mutation controls.
  • Analysis of EGFR TKI treatment response, including disease control rate (DCR) and objective response rate (ORR).
  • Comparison of overall survival (OS) and progression-free survival (PFS) between mutation groups using log-rank test.

Main Results:

  • Out of 443 patients with EGFR mutations, 22 (4.97%) had compound mutations.
  • No significant difference in DCR or ORR was observed between the L858R compound mutation group (n=6) and the single L858R mutation group (n=18).
  • Log-rank analysis revealed no significant differences in OS or PFS between the compound and single mutation groups.

Conclusions:

  • EGFR exon 21 L858R compound mutations do not appear to significantly alter the response to EGFR TKIs compared to single L858R mutations.
  • The presence of compound L858R mutations does not confer a different prognosis in terms of survival outcomes for NSCLC patients treated with EGFR TKIs.
  • These findings suggest that current EGFR TKI treatment strategies may be equally effective for both compound and single L858R mutations in NSCLC.
Keywords:
EGFR mutationcompound mutationsnon-small-cell lung cancer

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