Second-line treatment in EGFR-unselected patients: is it time to close one arm of this river’s DELTA?

Non-small cell lung cancer (NSCLC) remains the leading cause of cancer-related death worldwide. Despite advances in treatment, most patients will eventually relapse. Nowadays, there are four monotherapy options available for second-line standard treatment for patients with stage IV NSCLC: pemetrexed (for non-squamous NSCLC), docetaxel, erlotinib or gefitinib (1,2). Current practice guidelines do not require epidermal growth factor receptor (EGFR) mutation status testing before initiating a second-line therapy with an EGFR tyrosine kinase inhibitor (TKI).