Clinical characteristics and prognostic value of EGFR mutation in stage I lung adenocarcinoma with spread through air spaces after surgical resection.

The clinical data of stage I invasive lung adenocarcinoma patients with spread through air spaces (STAS) who underwent lobectomy from January 1, 2013 to January 1, 2016 at the Department of Thoracic Surgery of Hebei Medical University were analyzed retrospectively, and statistical analysis was carried out to explore their clinical features and prognostic value of EGFR mutation. A total of 280 patients were included in the study cohort, and EGFR mutations were detected in 154 patients. EGFR mutations were more common in non-smokers (p=0.045), females (p<0.001), without vascular tumor thrombus (p=0.037), and histological subtype LPA/APA/PPA (p=0.001). Multivariate analysis of the Cox risk regression model showed that EGFR gene mutation (p=0.807) was not an independent influencing factor of recurrence-free survival (RFS), but EGFR mutation was an independent influencing factor of overall survival (OS) (p=0.012), and OS of patients with EGFR mutation was better. The EGFR mutation also significantly increased the progression-free survival (PFS) of relapsed patients (p<0.001), but the PFS of relapsed EGFR mutation patients who received adjuvant chemotherapy after the operation was worse than that of patients who did not receive adjuvant chemotherapy (p=0.029). EGFR gene mutation is not a risk factor for postoperative recurrence in patients with stage I lung adenocarcinoma with STAS but the 5-year survival rate of patients with EGFR gene mutation is better than that of wild-type. Postoperative adjuvant chemotherapy for patients with EGFR mutation should be carefully considered.