A 55-year-old non-smoking woman is found to have a peripheral lung adenocarcinoma. Molecular profiling reveals an EGFR exon 19 deletion. Which first-line treatment strategy is MOST appropriate based on current guidelines?
- A Platinum-based doublet chemotherapy with pemetrexed
- B Third-generation EGFR TKI (osimertinib) targeting EGFR with reduced T790M resistance risk ✓
- C Anti-PD-L1 immunotherapy (pembrolizumab) regardless of PD-L1 expression
- D Crizotinib targeting ALK/ROS1 rearrangement
Correct answer: B. Third-generation EGFR TKI (osimertinib) targeting EGFR with reduced T790M resistance risk
Explanation
EGFR-mutant (exon 19 deletion or exon 21 L858R) non-small cell lung adenocarcinoma is treated first-line with osimertinib (third-generation EGFR TKI), which demonstrated superior PFS and OS over first-generation TKIs in the FLAURA trial. Osimertinib also penetrates the CNS and reduces the risk of T790M resistance emergence. ALK inhibitors (crizotinib, alectinib) are for ALK-rearranged tumours, not EGFR-mutant.
Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.