BACKGROUND: Historically, recommended tx for most patients (pts) with stage I–IIIA NSCLC was complete resection ± adjuvant chemotherapy (CT); however, 5-year (yr) overall survival (OS) rates with this approach (~30–90%) decrease with advancing disease stage. Osimertinib is a third generation EGFR TKI approved as adjuvant tx for resected stage IB–IIIA EGFR mutated NSCLC, based on results from the ADAURA trial. To understand rw data prior to adjuvant osimertinib approval, we report EGFR mutation (EGFRm) types, tx patterns and clinical outcomes from the South Korean cohort of a global retrospective rw study.
METHODS: Pts ≥18 yrs with completely resected stage IA–IIIA NSCLC and a positive EGFRm test result, diagnosed between 01 Jan 2014 and 31 Dec 2017, were assessed from diagnosis (Dx) until 31 Dec 2020 or last follow-up/death. Primary objectives included: frequency of EGFRm types, tx patterns and OS. Site of first recurrence was a secondary objective.
RESULTS: Of 200 pts in South Korea with a positive EGFRm test result, 95 (48%) had Ex19del and 87 (44%) L858R. At Dx, median age was 62 yrs (range: 36–83), 133 pts (67%) were female and 145 (73%) were never smokers; 68 pts (34%) had stage IA disease, 43 (22%) IB, 20 (10%) IIA, 15 (8%) IIB and 54 (27%) IIIA. In total, 90 pts (45%) received surgery only; 74 (37%) received surgery and adjuvant tx only (see Table). After a median follow-up of 54.7 months from Dx (interquartile range: 44.5–70.1), 5-yr OS rate was 69% (96% in stage IA, 84% IB, 72% IIA, 73% IIB and 26% IIIA). Of 106 pts who received any systemic tx with first recurrence data available, 53 had metastatic recurrence, most commonly in the lung (19/53; 36%) and brain (18/53; 34%).
CONCLUSIONS: In this rw study of pts in South Korea with resected EGFRm-positive early-stage NSCLC (Dx between 2014–2017), the majority (>90%) had Ex19del or L858R. Overall, 74 pts (37%) received adjuvant tx only; most frequently CT (73/74; 99%). The 5 yr OS rate was 69%.
