Clinical outcomes of thoracic radiotherapy for locally advanced nsclc with EGFR mutations or EML4-ALK rearrangement

Background: Little is known about the occurrence and consequences of epidermal growth factor receptor gene (EGFR) mutations and the fusion of the echinoderm microtubule-associated protein-like 4 (EML4) and anaplastic lymphoma kinase (ALK) genes in locally advanced non-small cell lung cancer (NSCLC). Patients and Methods: We retrospectively examined 37 patients with locally advanced NSCLC treated with definitive thoracic radiotherapy (TRT). Characteristics were compared among patients classified positive for EGFR mutations, EML4-ALK rearrangement, or patients who were double-negative for these changes. Results: We identified 11 (29.7%) patients with EGFR mutations and 3 (8.1%) with an EML4-ALK rearrangement. Progression-free survival of patients with EGFR mutation-positive NSCLC was similar to the one of those with double-negative disease (13.1 and 18.6 months). The incidence of local recurrence was higher in EGFR mutation-positive patients with NSCLC than in double-negative NSCLC. Conclusion: EGFR mutations and the EML4-ALK rearrangements were detected in substantial proportions of patients with locally advanced NSCLC. The efficacy of TRT was limited in patients with EGFR mutations.