Similar Trend in Benefit of Adjuvant Platinum in Lung Cancer Patients Irrespective of Epidermal Growth Factor Receptor Mutation Status

Abstract

Objectives Adjuvant osimertinib is currently the standard of care after pulmonary resection in patients with non-small cell lung cancer (NSCLC) harbouring an activating epidermal growth factor receptor (EGFR) mutation. Several guidelines recommended up to 4 cycles of adjuvant platinum-doublet before adjuvant osimertinib treatment. However, whether adjuvant platinum-doublet prolongs the overall survival (OS) of patients with EGFR-mutated NSCLC as it did in the unselected LACE meta-analysis cohort is unclear. Methods A multicentre retrospective observational study was conducted at 21 centres in Japan, enrolling 4181 patients with lung adenocarcinoma who received pulmonary resection between 2015 through 2018. In this study, we compared the efficacy of adjuvant platinum-doublet between EGFR mutated and EGFR wild-type cohort focusing on 706 patients with pathological stage II-III disease. Propensity score matching (1:1 ratio, caliper = 0.2) was used to balance patient characteristics (age, sex, smoking, preoperative performance status, pathological stage, and EGFR status) between patients who received adjuvant treatment and those who did not. Results Among the 706 patients, 391 (55%) received adjuvant platinum-doublet. After 1:1 propensity score matching, patient characteristics were well balanced in the 2 groups (201 patients each). In subgroup analysis of overall and recurrence-free survival, the hazard ratios of adjuvant treatment were similar in the EGFR-mutated and EGFR wild-type groups (eg, OS, 0.56 [95% CI, 0.29-1.10] and 0.52 [95% CI, 0.33-0.82] in EGFR-mutated and EGFR wild-type subgroup, respectively). Conclusions Adjuvant platinum-doublet chemotherapy showed similar trends of benefit in the EGFR-mutated and EGFR wild-type subgroups.