Optimal Adjuvant Therapy in Resected Stage IIIA-N2 Non-Small-Cell Lung Cancer Harboring EGFR Mutations

Some non-small-cell lung cancer (NSCLC) patients are unexpectedly diagnosed with stage IIIA-N2 disease at the time of thoracoscopy or thoracotomy. Because of the limited statistical evidence of induction chemotherapy for these patients, it is necessary to develop more profound treatment strategies.

The demographic and clinical characteristics of patients with stage IIIA-N2 NSCLC harboring epidermal growth factor receptor (EGFR) mutations after radical resection were retrospectively reviewed. The patients were divided into 3 groups based on treatment: EGFR tyrosine kinase inhibitors (EGFR-TKIs, erlotinib or gefitinib), adjuvant chemotherapy (docetaxel plus cisplatin), and combination treatment (chemotherapy plus EGFR-TKIs). The effect of adjuvant therapy on survival rate was assessed using univariate and Cox regression analyses.

Patients receiving EGFR-TKIs alone showed significantly improved disease-free survival (DFS; p = 0.025) when compared to those receiving chemotherapy alone. Compared to chemotherapy alone, the combination of chemotherapy and EGFR-TKIs resulted did not significantly improve DFS (p < 0.001) and overall survival (OS p < 0.001). The combination of EGFR-TKIs with chemotherapy as adjuvant therapy led to improvements in both DFS (p = 0.116) and OS (p = 0.039) compared to patients receiving a EGFR-TKI monotherapy. Toxicities were mild in the 3 treatment groups.

Our study demonstrated that adjuvant EGFR-TKI treatment significantly increased the DFS of patients with stage IIIA-N2 NSCLC when compared with cisplatin-based chemotherapy. The use of EGFR-TKIs and chemotherapy is recommended in the setting of combined-modality therapy.