P1.02-014 HER2 Mutations in Chinese Patients with Non-Small Cell Lung Cancer

Abstract

ERBB2 (HER2) is a driver gene identified in non-small cell lung cancer (NSCLC). The prevalence, clinicopathology, genetic variability and treatment of HER2-positive NSCLC in Chinese population are unclear. Eight hundred and fifty-nine patients with pathologically confirmed NSCLC were screened for HER2 mutations using Sanger sequencing. Next-generation sequencing (NGS) was performed in positive cases. HER2 amplification was detected with FISH. Overall survival (OS) was evaluated using Kaplan-Meier methods and compared with log-rank tests. Twenty-one cases carrying HER2 mutations were identified with a prevalence of 2.4%. HER2 mutations were more frequently encountered in females, non-smokers and adenocarcinoma. NGS was performed in 19 out of 21 patients, The results showed 16 cases with additional genetic aberrations, most commonly associated with TP53 (n = 6), followed by EGFR (n = 3), NF1 (n = 3), KRAS (n = 2) and other mutations. One patient harbored HER2 amplification (figure 1). Four patients with stage IV received afatinib treatment, and three showed stable disease with a median progression-free survival of 4 months and one patient was diagnosed with progressive disease. No survival difference existed between HER2 positive and negative patients (49.3 months vs.45.0 months, P = 0.150). HER2 mutations represent a distinct subset of NSCLC. NGS showed that HER2 mutations commonly co-existed with other driver genes. Afatinib treatment displayed moderate efficacy in patients with HER2 mutations.