Risk Factors For Brain Metastases In Advanced Non-Small Cell Lung Cancer

Objective:Brain metastasis has become one of the most important factors of the failure treatment of advanced non-small cell lung cancer (NSCLC).We intended to identify risk factors that affect brain metastases (BM) in patients with NSCLC, which may guide the choice of patients of high risk brain metastases in clinical.Methods:The clinical data of 158 advanced NSCLC patients hospitalized from April 2008 to June 2013 were extracted and then retrospectively analyzed (no brain metastasis 96, brain metastasis 62). All the enrolled patients had newly diagnosed NSCLC with stage IV and not received treatment previously. We tried to identify age, gender, smoking, ECOG score, pathological type, EGFR mutation status, serum CEA level, LDH levels associated with advanced NSCLC brain metastases. Then the 62 cases of treatment of patients with brain metastases were analyzed.Results:1. The incidence of brain metastasis was 39.2%(62/158), at the time of initial diagnosis of NSCLC 13.9%(22/158), the 1-year and 2-year brain metastasis rates were 30.3%(48/158)and 37.9%(60/158), respectively. The median survival for all patients was 14.8 months, the 1-year and 2-year survival rate were 62% and 26%. The median survival of brain metastasis patients was 12.3 months, the 1-year and 2-year survival rate was 52% and 22%. The median survival of no brain metastasis patients was 16.4 months, the 1-year and 2-year survival rate was 68% and 28%.2. The area under the ROC curve was 0.65 (p<0.001,95% confidence interval of 0.562-0.738), serum CEA value of=15 ng/ml seemed to be the appropriate cut-off level for the prediction of brain metastasis with 67% of sensitivity,61.4% of specificity,39 out of 77(50.6%) patients with CEA>15ng/ml and 23 out of 81 (28.3%) patients with CEA≤15ng/ml presented brain metastasis.3. In univariate analysis, smoking, adenocarcinoma, CEA>15ng/ml and ≤2 line chemotherapy were significantly associated with BM; but age, gender, ECOG score, EGFR mutation status and LDH were no correlation with BM.4. In logistic regression analysis, smoking (OR2.452,95% CI: 1.138-5.169,P= 0.022), adenocarcinoma (OR2.389,95% CI:1.029-5.547; P=0.043), serum CEA>15ng/ml (OR2.422,95% CI:1.181-4.965,P= 0.016)and ≤2 line chemotherapy (OR 3.140,95% CI:1.477-6.676,P =0.003)were independent risk factors for BM.5.The prognosis of brain metastases was associated with treatments (P<0.05),The median survival for the monotherapy group and the combined treatment group were 3months and 14 months respectively; The median survival time for brain radiotherapy group and no brain radiotherapy group were 14months and 6 months respectively; the median survival time for targeted therapy group and non-targeted therapy group were 17months and 6 months respectively. In targeted therapy group,6 cases with EGFR mutations, the median survival was 17 months, significantly longer than patients with wild-type EGFR one case 3months.Conclusion:smoking, adenocarcinoma, serum CEA>15ng/ml and ≤2 line chemotherapy were independent risk factors for advanced non-small cell lung cancer brain metastasis, the prognosis of brain metastases was associated with treatments, the best treatment for brain metastases of patients was multidisciplinary treatment, and based on the specific circumstances we should be taken in patients with individualized treatment strategies.