Coexistence of sensitive and resistant epidermal growth factor receptor (EGFR) mutations in pretreatment non-small cell lung cancer (NSCLC) patients: First or third generation tyrosine kinase inhibitors (TKIs)?

For patients harboring primary resistant and sensitive mutations detected by routine clinical methods, first generation TKIs are ineffective even with the presence of sensitive mutations. However, osimertinib shows great survival benefit, and thus, should be considered during the whole clinical management.