Strong response to first-line osimertinib and chemotherapy in EGFR L861Q-mutant NSCLC: a case report

Report Clinical Practice Points-Patients with non-small cell lung cancer (NSCLC) harboring uncommon EGFR mutations such as L861Q often experience suboptimal outcomes with first-line EGFR TKI monotherapy, including lower response rates and shorter progression-free survival compared to common EGFR mutations.This case illustrates a durable clinical response to first-line osimertinib combined with carboplatin and pemetrexed in a patient with EGFR L861Q-mutant NSCLC, suggesting that treatment intensification may be beneficial in select patients with uncommon mutations.Clinicians may consider continuing chemotherapy while initiating targeted therapy in patients with aggressive disease, especially when initial chemotherapy has already produced a favorable response and uncommon EGFR mutations are later identified.