EGFR and non-small cell lung carcinoma: A total of 442 patients diagnosed with stage IV NSCLC were collected in this study, excluding 81 patients whose disease had not yet progressed after treatment with first-line EGFR-TKIs, and a total of 361 patients showed disease progression requiring second-line treatment, of whom 43 patients received targeted therapy with third-generation EGFR-TKIs, and 123 patients met the inclusion criteria of this study.