Pathological Features and Differential Efficacy of Cisplatin-Based Adjuvant Chemotherapy in Lung Cancer Harboring Epidermal Growth Factor Receptor Mutations.

PURPOSE

We aimed to elucidate the efficacy of conventional cisplatin-based adjuvant chemotherapy for patients with lung cancers harboring epidermal growth factor receptor (EGFR) mutation.

METHODS

This retrospective cohort study included 110 patients (EGFR mutation group: n = 51; EGFR wild-type group: n = 59) receiving cisplatin-based adjuvant chemotherapy following complete resection of non-small-cell non-squamous-cell lung cancer (2010-2021). Clinicopathological characteristics, recurrence-free survival (RFS), and overall survival (OS) were investigated.

RESULTS

The pStage distribution was not statistically different. The EGFR mutation group was characterized by more advanced pN, papillary predominance, and presence of micropapillary components, whereas the EGFR wild-type group exhibited more advanced pT and solid predominant patterns. The median RFS was significantly worse in the EGFR mutation group (23.0 vs. 76.1 months, p = 0.017). Nevertheless, the median OS was not significantly different (85.6 months vs. not reached, p = 0.151). Multivariable analysis demonstrated that EGFR mutation and lymphatic invasion were significant risk factors in RFS; however, no independent factors were identified in OS.

CONCLUSIONS

Cisplatin-based adjuvant chemotherapy might be less effective in patients with EGFR-mutated lung cancer. The style of progression and histological pattern related with EGFR mutation may be associated with the efficacy of adjuvant chemotherapy and poor RFS.