[The research status and development trend of EGFR gene exon 20 insertion mutant non-small cell lung cancer].

The successful application of tyrosine kinase inhibitor (TKI) has kicked off the targeted therapy of epidermal growth factor receptor (EGFR) mutant non-small cell lung cancer (NSCLC) since the discovery of EGFR gene mutations. Patients harboring the two most classic representative mutations of EGFR gene including exon 19 in-frame deletion or exon 21 L858R mutation could get significant clinical benefits from EGFR-TKIs compared to traditional chemotherapy. Among other approximately 10% of EGFR gene mutation type, exon 20 insertion occupies the first place. Available research had demonstrated that EGFR exon 20 insertion in NSCLC was highly malignant and most insertion variants showed de novo drug resistance towards current approved 1(st) to 3(rd) generation EGFR-TKIs, with much poorer clinical prognosis. Currently, there is a lack of comprehensive research and clinical guideline on the treatment of this specific mutation. In this article, we review the pathogenesis, amino acid sequence variants and current management of EGFR exon 20 insertion mutant NSCLC. Moreover, we come up with the emphasis on the treatment challenges and further development of this rigid mutation in NSCLC.