EGFR mutation status, treatment patterns, and outcomes in resectable early-stage non-small cell lung cancer prior to adjuvant EGFR-TKI approval: An international real-world study

OBJECTIVES: Historically, resection followed by chemotherapy was standard treatment for stage II-III non-small cell lung cancer (NSCLC) and selected patients with stage IB disease. However, recurrence was common post-resection. Genomic characterization of early-stage NSCLC and precision medicine have since provided more effective therapies. Real-world evidence prior to practice-changing approvals aids understanding of the disease and treatment landscape, and establishment of benchmarks for future studies. We report an international, retrospective, real-world study of patients with early-stage NSCLC. MATERIALS AND METHODS: Medical records were reviewed for patients ≥18 years with completely resected stage IA-IIIA NSCLC (diagnosed January2014-December2017) and an EGFR mutation test result from centers in Austria, Canada, France, Germany, Republic of Korea, Taiwan, the UK, and the US. Data were analyzed from diagnosis until December 2020 (UK until February 2021). Primary objectives included the proportion of patients with EGFR mutation-positive NSCLC, treatment patterns, and overall survival (OS). Analyses were descriptive, with OS estimated using Kaplan-Meier methods. RESULTS: Of 1043 patients (stage IA: 35%; IB: 22%; IIA: 15%; IIB: 10%; IIIA: 18%), 330 (32%) had EGFR mutation-positive NSCLC. Fifty-two percent of patients underwent surgical resection only; 29% (predominantly stage II-IIIA) received surgery plus adjuvant treatment ≤26 weeks post-surgery. The most common adjuvant treatment was chemotherapy for EGFR mutation-positive (97/103; 94%) and -negative NSCLC (193/195; 99%). Five-year OS rates were 84% (median follow-up 60.8 months) and 64% (median follow-up 51.3 months) for patients with EGFR mutation-positive and -negative NSCLC, respectively. Lung and brain were the most common sites of recurrence. CONCLUSIONS: In this real-world study, prior to the approval of osimertinib as adjuvant treatment for resected NSCLC, only one-third of patients received adjuvant treatment within 26 weeks post-surgery, highlighting its underutilization and emphasizing the critical need for early EGFR mutation testing to inform optimal treatment choices.