A Real-world Study Of Osimertinib In The First-line Treatment Of Brain Metastasis Patients With EGFR-mutated Non-small-cell Lung Cancer

Objective: To evaluate the efficacy,prognosis,and the safety of osimertinib,a third-generation EGFR tyrosine kinase,in first-line treatment of NSCLC patients of brain metastases(BMS)with EGFR-mutated,and provide a clinical practice basis for the clinical application and promotion of osimertinib.Methods: A total of 82 NSCLC patients of BMS with EGFR-mutated who treated by first-line osimertinib at Xiangya Hospital of Central South University from January 2018 to August 2021 were enrolled.The efficacy after treated 3 months was estimated by the indexes of intracranial objective response rate(i ORR),intracranial disease control rate(i DCR),and the incidence of adverse reactions during the period of treatment.All patients were followed up for disease progression or death after treatment.The overall survival rate(OS)rate and progression-free survival(PFS)rate,and prognostic factors were analyzed using the Cox proportional hazard regression model.Results: The overall i ORR and i DCR of NSCLC patients of BMS with EGFR-mutated were 69.5% and 95.1% after 3 months of first-line treatment with osimertinib,respectively.After treatment,the proportion of patients with central nervous system symptoms decreased significantly compared with before treatment(P=0.002),and the brain lesions decreased significantly compared with before treatment(P<0.001).The incidence of adverse reactions was 50.0% and the highest incidence was rash.There was no significantly statistical significance between the patients with meningeal metastasis and parenchymal metastasis in the period of treatment(P=1.000).The rate of OS in 82 NSCLC patients with BMS was 73.2%,and the PFS was 65.9%.The results of prognostic factors analysis showed that the risk of death in NSCLC patients with EGFR mutation type 19 del was 0.358 folds compared with EGFR mutation type L858R(P=0.040).NSCLC patients of BMS with EGFR-mutated with an age above 60 years was 4.385 folds of the risk of disease progression compared with that age less than or equal to 60 years(P=0.020).Conclusion: A better curative effect with i ORR and i DCR can be observed in the NSCLC patients of BMS with EGFR-mutated who treated by first-line osimertinib,and no serious adverse reactions occurred during treatment.EGFR mutation type with L858 R and age >60 years are the risk factors for prognosis of NSCLC patients of BMS with EGFR-mutated treated with osimertinib.