Frequency, underdiagnosis and heterogeneity of epidermal growth factor receptor exon 20 insertion mutations using real‐world genomic datasets

Epidermal growth factor receptor (EGFR) exon 20 insertion mutations (ex20ins) account for ≤12% of all EGFR‐mutant non‐small cell lung cancers. This study analyzed real‐world datasets to determine the frequency of ex20ins variants and polymerase chain reaction (PCR) and next‐generation sequencing (NGS) ability to identify them. An analysis of variants projected that PCR‐based assays would have missed ~50% of EGFR ex20ins identified by NGS. Given the breadth of EGFR ex20ins identified in real‐world datasets, the ability of PCR to identify these mutations is limited. NGS platforms are more appropriate for identifying patients likely to benefit from EGFR ex20ins‐targeted therapies.