Targeting Classical EGFR Mutations in Lung Cancer: Twenty Years of Progress and Beyond

The discovery of activating epidermal growth factor receptor (EGFR) mutations transformed the management of non-small cell lung cancer and has driven two decades of therapeutic advances in precision oncology across metastatic, resectable, and unresectable locally advanced disease, including central nervous system (CNS) control. Consequently, treatment outcomes for patients with tumors harboring classical EGFR mutations have markedly improved. Despite these advances, many questions remain unanswered, and the expanding number of treatment options has created new challenges in treatment selection and sequencing. This narrative review summarizes contemporary data on the management of classical EGFR-mutant NSCLC, encompassing novel therapeutic approaches across disease stages, biomarker-informed resistance strategies, multimodality treatment integrating radiotherapy, CNS-directed management, and challenging scenarios such as small-cell transformation. We also discuss emerging fourth-generation inhibitors, nucleic-acid delivery platforms, and data-enabled personalized treatment. We highlight evolving standards of care, unresolved knowledge gaps, and research priorities for the next decade.