EGFR-mutation testing and TKI treatment patterns in locally advanced and metastatic NSCLC in Norway – A nationwide retrospective cohort study

Abstract

Background: Testing for epidermal growth factor receptor mutation (EGFRm) status is a prerequisite to identify eligible patients for tyrosine kinase inhibitors (TKI) treatment. However, EGFR testing of patients with non-small cell lung cancer (NSCLC) is suboptimal in many parts of the world. The aim of this study was to describe real-world EGFR testing practice, EGFRm prevalence, and subsequent TKI treatment patterns in Norway. Patients and methods: This retrospective, observational, cohort study included all incident locally advanced and metastatic non-squamous NSCLC patients registered in the Norwegian Cancer Registry during 2010–2017. A cohort with follow-up through 2018 was formed with linkage to nationwide registries on comorbidities, prescribed drugs and causes-of-death. Results: A total of 10,717 patients were included, of which 35% (3782) with locally advanced NSCLC and 65% (6935) with metastatic disease. Mean age at diagnosis was 71 years and 47% were female. EGFR testing among patients with metastatic NSCLC increased from 41% to >64% between 2010 and 2017, with a relative stable incidence of EGFRm+ (∼9%). More than 85% of EGFRm+ patients received TKI treatment. Patients with the most dismal prognosis (>80 age, comorbidities) and with diagnosis based on cytology/imaging were less likely to be tested. Differences in testing were observed between regions. Conclusion: Despite increased test rates over the study period, in Norway, a significant proportion of patients with non-squamous metastatic NSCLC are still not tested for EGFR. To maximize the identification of eligible patients for targeted therapies, increased testing is recommended, regardless of age, comorbidity rate and place of residence.

Keywords

• Non-small cell lung cancer
• Epidermal growth factor receptor
• Tyrosine kinase inhibitors