Prevalence of EGFR mutations in patients with resected stage I-III non-small cell lung cancer: results from EARLY-EGFR Latin America study.

Background: Although targeted and immune-based therapies are now recommended for early-stage non-small cell lung cancer (NSCLC), data on biomarker prevalence in Latin America (LATAM) remain limited. The aim of the descriptive, observational, real-world, EARLY-EGFR (NCT04742192) study was to determine the frequency of EGFR-mutated (EGFRm) in patients with resected stage I-III NSCLC across Asia, Middle East and Africa and LATAM. Methods: The LATAM subset prospectively enrolled patients with surgically resected stage IA-IIIB [American Joint Committee on Cancer (AJCC) 8th edition] non-squamous NSCLC from March 2021 to October 2022. Primary endpoint was EGFRm prevalence and secondary endpoints were EGFRm subtypes, clinico-demographics and treatment patterns. Associations were analyzed by Fisher's exact test with Monte Carlo. Results: Of 80 patients (mean ± standard deviation age of 66.5±9.7 years) enrolled, 67.5% were females and 57.5% were never smokers. Most patients had pathological stage (PS) stage I (66.3%) NSCLC, with 85.0% patients having pN0; all patients had adenocarcinoma. Most patients (61.3%) had right lung involvement. More than one-third of patients (39.5%; 30/76) had EGFRm with similar rates in males and females (39.1% vs. 39.6%). Exon-19 deletions (36.7%) and 21-L858R (30.0%) accounted for two-thirds of mutations. Four of 11 (36.4%) patients with EGFRm were found to be programmed death ligand-1 (PD-L1) positive. EGFRm rate in never smokers was significantly higher than in current and former smokers (51.2% vs. 24.2%, P=0.02). A total of 76.3% underwent only surgical resection. Of 44 PS IB-IIIB patients, 40.9% were prescribed systemic adjuvant therapy (AT), mostly platinum-based chemotherapy. Per logistic regression, age ≥60 years had increased odds of EGFRm, while smokers had decreased odds of EGFRm (both P<0.05). Conclusions: The LATAM subset shows an EGFRm prevalence of 39.5%. Despite American Society of Clinical Oncology guidelines recommending AT in PS IB-IIIB, only about 32% received it. Our results are important for guiding EGFR testing and informing treatment strategies in LATAM with recent and upcoming approvals of targeted and immunotherapy.