Efficacy of Osimertinib in Patients with Postoperative Recurrent Non-Small-Cell Lung Cancer Harboring Sensitizing EGFR Mutations.

ABSTRACT Background The efficacy of osimertinib in patients with postoperative recurrent non–small‐cell lung cancer (NSCLC) compared to those with Stage IV NSCLC harboring epidermal growth factor receptor (EGFR) mutations remains unclear. Methods This study evaluated the efficacy of osimertinib in patients with postoperative recurrent EGFR‐mutated NSCLC. We retrospectively evaluated patients with NSCLC harboring EGFR mutations (exon 19 deletion or L858R mutation) who received osimertinib between September 2018 and July 2022 at a single institution. The efficacy of osimertinib was compared between patients with postoperative recurrent NSCLC (postoperative group) and those with Stage IV NSCLC (Stage IV group). Results Among a total of 172 patients treated with osimertinib, 52 were classified into the postoperative group and 120 into the Stage IV group. The response rate (58.1% vs. 61.8%, p = 0.836) and progression‐free survival (hazard ratio [HR]: 0.854, 95% confidence interval [CI]: 0.558–1.306, p = 0.465) were not significantly different between the postoperative and Stage IV groups. Overall survival (OS) was significantly longer in the postoperative group than in the Stage IV group (median: 39.2 months and 28.5 months, respectively; HR: 0.521, 95% CI: 0.293–0.927, p = 0.024). In the multivariable analysis of OS, postoperative recurrent disease and performance status were independent favorable prognostic factors. Conclusions Postoperative recurrent disease was an independent favorable prognostic factor in patients with NSCLC harboring EGFR mutations treated with osimertinib.