Efficacy of platinum-based adjuvant chemotherapy for epidermal growth factor receptor-mutant lung adenocarcinoma

Ken Onodera; Isao Yokota; Yuki Matsumura; Kazuki Hayasaka; Satoshi Shiono; Jiro Abe; Hirotsugu Notsuda; Akira Sakurada; Hiroyuki Suzuki; Yoshinori Okada

doi:10.21037/jtd-23-1323

Efficacy of platinum-based adjuvant chemotherapy for epidermal growth factor receptor-mutant lung adenocarcinoma

J Thorac Dis. 2023 Dec 30;15(12):6534-6543. doi: 10.21037/jtd-23-1323. Epub 2023 Dec 4.

Authors

Affiliations

¹ Department of Thoracic Surgery, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Miyagi, Japan.
² Department of Biostatistics, Graduate School of Medicine, Hokkaido University, Sapporo, Hokkaido, Japan.
³ Department of Chest Surgery, Fukushima Medical University, School of Medicine, Fukushima, Japan.
⁴ Departments of Thoracic Surgery, Yamagata Prefectural Central Hospital, Yamagata, Japan.
⁵ Department of Thoracic Surgery, Miyagi Cancer Center, Natori, Miyagi, Japan.

Abstract

Background: The ADAURA trial reported that osimertinib improved overall survival (OS) as an adjuvant chemotherapy for pathological stage IB-IIIA epidermal growth factor receptor (EGFR) mutant lung cancer compared with a placebo. Currently, platinum-based adjuvant chemotherapy is the standard treatment for patients with or without EGFR mutations. This study aimed to evaluate the efficacy of platinum-based adjuvant chemotherapy in patient with stage II-IIIA EGFR mutant lung adenocarcinoma.

Methods: We collected the medical records of consecutive patients who underwent surgical resection for lung adenocarcinoma between 2005 and 2012 at the four participating institutions. The data of 173 patients with different EGFR mutation status were retrospectively evaluated to determine the efficacy of platinum-based adjuvant chemotherapy for OS and recurrence-free survival (RFS). We further analyzed OS using the inverse probability of treatment weighting method with propensity scores.

Results: The median age was 69 years (range, 45-85 years); 95 (54.9%) were male and 74 (42.8%) had EGFR mutations. A total of 43 patients with EGFR mutants (58.1%) and 43 patients with wild-type EGFR tumors (43.4%) received platinum-based adjuvant chemotherapy. No differences in RFS and OS were observed between EGFR mutant and wild-type EGFR in lung adenocarcinoma without adjuvant therapy. However, wild-type EGFR showed an improvement in OS with platinum-based adjuvant chemotherapy in inverse probability of treatment weighting analysis, whereas those with EGFR mutations showed no significant difference in OS between the surgery-only group and the adjuvant group. The deletion of exon 19 and exon 21 L858R point mutation showed no significant differences in OS between the surgery-only group and the adjuvant group, respectively. The hazard ratio (HR) exceeded 1 for uncommon EGFR mutations.

Conclusions: Platinum-based adjuvant chemotherapy may be less effective for EGFR-mutant lung adenocarcinoma, regardless of the mutation type.

Keywords: Lung cancer; adjuvant chemotherapy; epidermal growth factor receptor mutation (EGFR mutation); platinum-based chemotherapy.