Association between EGFR mutation types and incidence of brain metastases in postoperative patients with stage I–III NSCLC

This retrospective study aims to clarify the association between epidermal growth factor receptor (EGFR) mutation types and brain metastasis incidence in early-stage non-small-cell lung cancer after surgery.

Patients pathologically diagnosed with stage I to III non-small-cell lung cancer were consecutively enrolled from January 2010 to January 2017 and reviewed. First-generation TKIs were selected as postoperative therapy for those with EGFR mutations, and platinum-based chemotherapy was used as postoperative therapy for patients with negative wild-type gene mutations. A Kaplan–Meier approach was used to calculate the cumulative incidence of brain metastasis and overall survival. Candidate prognostic factors were checked by log-rank test.

A total of 669 patients were eligible for the study, comprising 309 who were EGFR(+), and 360 who were EGFR(−). Patients with any type of EGFR mutation have a significantly higher risk of developing brain metastases compared to those with EGFR wild-type (hazard ratio=1.957, P=0.012). The incidence of brain metastasis was 17.1% higher in patients with the 19Del mutation than in those with the L858R mutation (13.6%), other mutations (13.3%), or wild-type EGFR (6.1%). Moreover, those with 19Del mutations showed the greatest increase in incidence of brain metastasis (hazard ratio=3.009, P=0.001); those with L858R mutations showed a smaller increase (hazard ratio=2.750, P=0.003).

EGFR mutations are predictive factors for the cumulative incidence of brain metastasis. EGFR-mutant non-small-cell lung cancer patients may need more frequent brain magnetic resonance imaging to detect earlier occurrence of brain metastases, allowing for timely and effective treatment to improve patient prognosis.