The role of EGFR mutations in predicting recurrence in early and locally advanced lung adenocarcinoma following definitive therapy.

ABSTRACT

INTRODUCTION: Roughly one third of new non-small cell lung cancer (NSCLC) is diagnosed at early stages. While lobectomy can improve mortality in this group, about 30-55% of patients will experience disease recurrence. Increased investigation into the factors affecting recurrence, particularly tumor molecular genetics such as EGFR mutations, is needed. MATERIALS AND METHODS: We conducted a single-center retrospective study of 282 patients with early or locally advanced lung adenocarcinoma, with or without EGFR mutations, who underwent definitive therapy. We then assessed recurrence, stage at recurrence, time to recurrence and progression-free survival (PFS). RESULTS: We identified 142 patients with EGFR-mutated and 140 EGFR-wildtype lung adenocarcinoma. Overall progression between groups was equivalent at ~40% at 5 years; no difference in PFS was observed at any time-point. However, among those who recurred, EGFR-mutated lung cancer had increased rates of metastatic recurrence compared to EGFR-wildtype disease (97% vs 68%, p = 0.007). CONCLUSIONS: EGFR-mutated disease may be associated with a higher risk of metastatic recurrence. Molecular testing may be a promising tool for risk stratification and surveillance following definitive management for early stage disease. Future prospective, multi-center cohort studies are needed to confirm these findings and improve our understanding of how EGFR mutation contributes to prognosis and clinical outcomes.