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

[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.