Serum neurofilament light chain or glial fibrillary acidic protein in the diagnosis and prognosis of brain metastases.

INTRODUCTION: Brain metastases (BM) remains the most cumbersome disease burden in patients with lung cancer. This study aimed to investigate whether serum brain injury biomarkers can indicate BM, to further establish related diagnostic models, or to predict prognosis of BM.

MATERIALS AND METHODS: This was a prospective study of patients diagnosed with lung cancer with BM (BM group), with lung cancer without BM (NBM group), and healthy participants (control group). Serum neurofilament light chain (NfL) and glial fibrillary acidic protein (GFAP) were detected at baseline. We identified and integrated the risk factors of BM to establish diagnostic models.

RESULTS: A total of 158 patients were included (n = 37, 57, and 64 in the BM, NBM, and control groups, respectively). Serum biomarker levels were significantly higher in the NBM group than in the control group. Higher serum NfL and GFAP concentrations were associated with BM (odds ratios, 3.06 and 1.79, respectively). NfL (area under curve [AUC] = 0.77, p < 0.001) and GFAP (AUC = 0.64, p = 0.02) had diagnostic value for BM. The final diagnostic model included NfL level, age, Karnofsky Performance Status. The model had an AUC value of 0.83 (95% confidence interval [CI] 0.75-0.92). High NfL concentration was correlated with poor overall survival of patients with BM (hazard ratio, 3.31; 95% CI 1.22-9.04; p = 0.019).

CONCLUSION: Serum NfL and GFAP could be potential diagnostic biomarkers for BM in patients with lung cancer. We established a model that can provide individual diagnoses of BM. Higher NfL level may be associated with poor prognosis of patients with BM.