[EGFR mutation analysis in non-small-cell lung cancer : Experience from routine diagnostics]

Area of Science:

• Oncology
• Molecular Diagnostics
• Genetics

Background:

• Non-small cell lung cancer (NSCLC) patients exhibit variable responses to tyrosine kinase inhibitors (TKI).
• Somatic mutations in the epidermal growth factor receptor (EGFR) gene serve as a key predictive biomarker for TKI efficacy.

Purpose of the Study:

• To determine the prevalence of relevant EGFR mutations in a Central European NSCLC cohort.
• To investigate the association between EGFR mutations and clinical-pathological parameters.

Main Methods:

• EGFR mutation analysis was conducted on 307 NSCLC samples (exons 18-21).
• Statistical analysis was employed to correlate mutation status with clinical-pathological features.

Main Results:

• Relevant EGFR mutations were identified in 8.1% (25/307) of NSCLC cases.
• Exon 19 deletions were the most frequent (50%), followed by the L858R mutation in exon 21 (12.5%).
• EGFR mutations were significantly more common in women (16.8%) versus men (2.7%) and in adenocarcinomas (11.4%) versus other subtypes (3.8%).
• A strong association was observed between EGFR mutations and TTF-1 positivity (p<0.041), with 96% of mutated NSCLC cases being TTF-1 positive.

Conclusions:

• The prevalence of actionable EGFR mutations in NSCLC in Central Europe is below 10%.
• EGFR mutations are more frequently observed in female patients and in TTF-1 positive adenocarcinomas.
• EGFR mutation analysis is feasible using both biopsy and cytology specimens.