Characteristics of Patients with Non-Small Cell Lung Cancer and Epidermal Growth Factor Receptor Exon 20 Q787Q Mutation.

backgroundNon-small cell lung cancer (NSCLC) involves mutations in the epidermal growth factor receptor (EGFR) gene, which can be categorized as common and uncommon mutations. Among the uncommon mutations, EGFR exon 20 mutations occur most frequently. Of these, EGFR exon 20 Q787Q is a relatively frequent mutation and is a synonymous polymorphism mutation that does not alter the amino acid sequence of the EGFR protein; however, the effects of this mutation remain unclear. We analyzed the clinicopathological features and prognoses of patients with EGFR exon 20 Q787Q mutation in NSCLC.

methodsPatients diagnosed with NSCLC who underwent complete resection at Kitasato University Hospital between 2010 and 2017 were retrospectively reviewed for EGFR mutations. Patients with genetic mutations other than those in EGFR were excluded from the analysis. Patients with EGFR exon 20 Q787Q mutation were compared with those harboring wild-type EGFR using a cohort selected by propensity score matching.

resultsAmong the 693 eligible patients, EGFR mutations were assessed in 349 patients. Of these, 122 (35.0%) displayed common mutations, 72 (20.6%) exhibited uncommon or compound mutations, and 155 (44.4%) showed wild-type EGFR. Within the group exhibiting uncommon or compound mutations, 39 (11.2%) patients presented a single exon 20 Q787Q mutation. When the prognosis and recurrence rates were compared, patients with EGFR exon 20 Q787Q mutation exhibited superior overall survival and lower recurrence rates than those harboring wild-type EGFR.

conclusionsPatients with EGFR exon 20 Q787Q mutation, a synonymous polymorphism mutation, exhibited different characteristics compared with those harboring wild-type EGFR.