EGFR-mutation testing, treatment patterns and clinical outcomes in patients with stage IB-IIIA non-small cell lung cancer in Norway-a nationwide cohort study.

ABSTRACT

INTRODUCTION: Testing for mutations of epidermal growth factor receptor (EGFR) is crucial to identify non-small cell lung cancer (NSCLC) patients eligible for treatment with EGFR tyrosine kinase inhibitors (EGFR-TKIs); This study aims to describe EGFR-mutation testing, treatment patterns, and overall survival (OS) in localized NSCLC patients. MATERIALS AND METHODS: Patients with localized (Stage IB-IIIA) NSCLC registered in the Norwegian Cancer Registry during 2010-2017 were followed from diagnosis until emigration, death, or end of study in 2018. The cohort was linked to data from the Norwegian Patient Registry, the Prescription Database, and the Cause of Death Registry. RESULTS: Of 2367 patients identified with localized NSCLC, 52 % were females and median age at diagnosis was 69 years. Most (66 %) were treated with surgery, while 16 % received curatively-intended radiotherapy (RT). EGFR-mutation testing increased significantly from 58 to 84 % during the study period. Testing frequencies varied across regions and comorbidity levels. Nine-percent of tested patients were EGFR-mutation positive (EGFRm+), of whom 27 % were treated with EGFR-TKIs. There was no correlation between initial treatment with either surgery or RT and EGFR-TKI use. The 3-year OS did not vary considerably by EGFR-mutation testing, but EGFRm+ patients had a higher 3-year OS (78.8 %) than wild-type EGFR (EGFRwt) patients (65.9 %). DISCUSSION: Although EGFR-mutation testing is increasingly being implemented in the early-stage setting in line with national recommendations, some patients are still not being tested for molecular markers as part of their diagnostic workup-a prerequisite for providing equal access to effective targeted treatments, such as EGFR-TKIs, to eligible patients.