Construction of prognostic model for brain metastases in non-small cell lung cancer initially treated with third-generation EGFR-TKI and its relationship with the timing of stereotactic radiotherapy

DING Jinquan; HE Honghong; LI Weizhi; LI Xiaojing; ZHANG Qungui

doi:10.13276/j.issn.2097-1656.2025.12.018

Abstract：Objective To construct a risk prediction model for poor prognosis of brain metastases in non-small cell lung cancer(NSCLC)initially treated with third-generation epidermal growth factor receptor-tyrosine kinase inhibitor(EGFR-TKI)and further analyze the relationship between the timing of stereotactic radiotherapy and clinical prognosis.Methods A total of 91 newly treated NSCLC patients who received third-generation EGFR-TKI and stereotactic radiotherapy in Ganzhou Cancer Hospital from January 2020 to January 2021 were retrospectively included.Clinical characteristics,intracranial lesion remission,disease progression and overall survival were analyzed.Univariate and multivariate analysis was used for risk factors for poor prognosis of brain metastases in NSCLC treated with third-generation EGFR-TKI.A prediction model for prognosis of brain metastases in NSCLC initially treated with third-generation EGFR-TKI was constructed and its predictive efficacy was analyzed.Results The evaluated complete response rate and objective response rate of 91 patients receiving third-generation EGFR-TKI within 3 months were 26.37％(24/91)and 53.85％(49/91),respectively.The 91 patients were followed up for 9 to 36 months,and the median follow-up time was 24 months.The median progression-free survival was 16.0(95％ CI:8.0-21.6)months.The median intracranial progression-free survival was 17.0(95％ CI:9.0-32.4)months.The median overall survival was 20.0(95％CI:17.2-36.0)months.Univariate analysis showed that gender,KPS score,diagnostic specific prognosis evaluation grade score,number of brain metastases,EGFR mutation type and start time of brain radiotherapy were correlated with the overall survival of NSCLC patients with brain metastases initially treated with third-generation EGFR-TKI(P＜0.05).Among the results of multivariate analysis,low KPS score,low diagnostic specific prognosis evaluation grade score,EGFR 21 exon mutation and initiation of radiotherapy after brain metastases progression were all independent risk factors for overall survival of NSCLC patients with brain metastases initially treated with third-generation EGFR-TKI(P＜0.05).The results of the above multivariate analysis were used to construct the prognosis prediction model of patients at different time points.The survival of patients at 1,2 and 3 years was predicted by receiver operating characteristic curve,and the area under the curve was 0.786,0.780 and 0.756,respectively.Conclusion The poor prognosis of NSCLC patients with brain metastases initially treated with third-generation EGFR-TKI may be related to factors such as low KPS score,low diagnostic specific prognosis evaluation grade score,EGFR 21 exon mutation and initiation of radiotherapy after brain metastases progression.The mathematical model constructed by the above elements shows good predictive efficacy for the survival of patients.