Dramatic response to immunotherapy in an epidermal growth factor receptor-mutant non-small cell lung cancer: A case report

Abstract

BACKGROUND The advent of immune checkpoint inhibitors (ICIs) has revolutionized the management of several types of solid cancers, including lung cancer, by boostingthe body's natural tumor killing response. However, it is undeniable that only asmall proportion of non-small cell lung cancer (NSCLC) patients with epidermalgrowth factor receptor (EGFR) mutations can achieve long-term responses andbenefit from immunotherapy.CASE SUMMARYHerein, we report the case of a 48-year-old man diagnosed with stage IV lungadenocarcinoma with an EGFR L858R mutation who was administered pembrolizumabmonotherapy followed by pemetrexed and achieved a 10-month progression-free survival interval. In this case report, we show that ICIs were effectivefor our patient with EGFR-mutated NSCLC and discuss the characteristics ofpatients who can benefit from immunotherapy.CONCLUSIONWe suggest that patients with EGFR-mutated NSCLC with high PD-L1 expression (defined as ≥ 25%), the L858R mutation, smoking history, or pemetrexed pretreatmentmay benefit from immunotherapy