Analysis of prognostic factors influencing brain metastasis in EGFR-mutant lung adenocarcinoma and comparison of prognostic assessment models.

Patients with EGFR-mutant lung adenocarcinoma are at risk for brain metastasis (BM), which worsens prognosis. The present study aimed to investigate the prognostic factors affecting the prognosis of patients with locally advanced lung adenocarcinoma with epidermal growth factor receptor (EGFR) mutations following the development of brain metastases (BM) after radical radiotherapy and chemotherapy. The present study also aimed to evaluate four scoring systems: Recursive partitioning analysis (RPA), diagnosis-specific graded prognostic assessment (DS-GPA), basic score for BM (BSBM) and lung cancer-associated molecular (Lung-mol) GPA, for their predictive roles. A retrospective analysis was performed on the clinical data of 260 patients with lung adenocarcinoma with BM and EGFR mutation admitted to the Cangzhou Hospital of Integrated Traditional Chinese and Western Medicine-Hebei Province (Cangzhou, China), from January 2016 to December 2022. The Cox proportional hazard model identified statistically significant prognostic factors. The log-rank test assessed the predictive effect of the four prognostic scoring systems on survival. Receiver operating characteristic (ROC) curves were constructed and the area under the curve (AUC) of each system was calculated. Among the 260 patients analyzed, the median survival time was 28.7 months. Independent prognostic risk factors included a Karnofsky Performance Status (KPS) score of <80 [hazard ratio (HR)=2.706; 95% CI, 1.825-4.012; P<0.001], extracranial metastases (HR=2.296; 95% CI, 1.543-3.418; P<0.001) and treatment with first- or second-generation EGFR-tyrosine kinase inhibitors (TKIs; HR=7.155; 95% CI, 4.950-10.344; P<0.001). All four scoring systems (RPA, DS-GPA, BSBM and Lung-mol GPA) were significant predictors of 1-, 2- and 3-year survival (P<0.001). ROC curve analysis revealed that the Lung-mol GPA system had the highest AUC, significantly outperforming the other three systems (P<0.05). In conclusion, KPS score, the presence of combined extracranial metastases and the generation of EGFR-TKIs administered are key independent prognostic factors in patients with BM secondary to radical radiotherapy for EGFR-mutated lung adenocarcinoma. Among the RPA, BSBM, DS-GPA and Lung-mol GPA models, the Lung-mol GPA model demonstrated notably increased predictive accuracy in patient prognosis.