EGFR-TKI combined with radiotherapy in 105 patients of lung adenocarcinoma with brain metastasis: a retrospective study of prognostic factors analysis.

INTRODUCTION This study aimed to retrospectively analyze the response and prognosis factors for patients of lung adenocarcinoma with brain metastasis and epidermal growth factor receptor (EGFR) mutation, who were treated by EGFR-tyrosine kinase inhibitor (TKI) combined with brain radiotherapy (RT). METHODS From Jan 2021 to Jan 2024, the clinicopathological data of lung adenocarcinoma patients were collected from the First Affiliated Hospital of Hebei North University. SPSS version 26.0 statistical software was used for statistical analysis. P < 0.05 was determined to be statistically significant. RESULTS 105 patients were included. The 1, 2, 3-year overall survival (OS) rate was 82.9%, 61.2%, and 33.7%, respectively. 1, 2 ,3-year progression-free survival 1 (PFS1) rate was 62.7%, 36.6%, 22.1%. 1,2,3-year PFS2 rate was 80.8%, 54.6%, and 31.4%. The median OS, PFS1 and PFS2 was 29.8, 18.0 and 28.1 months, respectively. The COX multivariate analysis showed that gene mutation status and brain radiation dose were independent prognostic factors for OS; Gene mutation status, brain radiation dose, and response evaluation to initial treatment (response evaluation) are independent prognostic factors for PFS1; Clinical stage, gene mutation status, brain radiation dose, and response evaluation are independent prognostic factors for PFS2. CONCLUSION TKI combined with brain radiotherapy is effective on lung adenocarcinoma patients with EGFR mutation and brain metastasis. Patients with 19 Del or 21 L858R mutation and brain radiation doses ≥ 40 Gy have longer OS, PFS1, and PFS2, and complete remission (CR) + partial remission (PR) is associated with longer PFS1 and PFS2, Patients in stage IVA have longer PFS2.