Background: The prevalence of EGFR mutations (EGFRm) in resected stage I-III NSCLC remains controversial as prior research studies were retrospective in nature. EARLY-EGFR is the first prospective, international study to determine the prevalence of EGFRm and treatment patterns in patients (pts) with early-stage NSCLC. Methods: EARLY-EGFR (NCT04742192), a non-interventional real-world study, captured data on EGFRm status, treatment patterns, demographic, clinical and pathological characteristics in consecutively enrolled pts with surgically resected stage IA-IIIB (AJCC 8^th) non-squamous NSCLC (Mar 2021 – Oct 2022). The primary endpoint was prevalence of EGFRm and secondary endpoints included prevalence of EGFRm subtypes and treatment patterns. Results: Of 601 pts (median [range] age: 62 [30-86] yrs) enrolled at 33 centers across Middle East and Africa (n=16), Latin America (n=80), and Asia (n=505), 317 (52.7%) were females, 354 (58.9%) were never smokers. The majority had stage IA-IB NSCLC (64.1%) involving right lung (62.9%), no nodal involvement (81.5%), T1a-T2b tumor (82.7%), adenocarcinoma histology (98.7%), and 105/420 (25.0%) tumors were poorly differentiated. About 23.3% (130/559) were diagnosed through a screening program; 60/539 (11.1%) reported family history of lung cancer. The overall prevalence of EGFRm was 50.7% (300/592). Exon-19 deletions accounted for 50.3%, L858R mutations for 35.7%, and compound mutations for 2.3% of mutations. EGFRm tumors were found to be PD-L1 positive in 38.5% of cases (15/39). Women had higher EGFRm rate than men (63.6% vs 36.2%). Compared with EGFR wild type (wt), pts with EGFRm were more likely to be never smokers (39.5% vs 60.5%) and have stage I/II NSCLC (46.5% vs 53.5%) (Table). Of 216 stage II/III NSCLC pts, only 51.4% received systemic adjuvant therapy. Significantly higher EGFRm rates in stages I and II than in stage III NSCLC (p<0.001 and p=0.050) were found, while no significant difference was found between stages I and II NSCLC (p=0.158). Conclusions: In this first prospective, real-world study of EGFRm prevalence in resected NSCLC, stage III and smoking were independent predictors associated with decreased odds of EGFRm. The results highlight the need to adhere to ASCO adjuvant chemotherapy guidelines, as only half of stage II/III NSCLC pts received adjuvant systemic therapy. Clinical trial information: NCT04742192.

Unknown/missing data not included ^acurrent and ex-smoker vs never smoker; ^bstage I and II vs stage III.