Correlation Between Clinical Features Of Patients With Advanced NSCLC After The First Generation EGFR-TKIS Resistance And T790M Mutation,the Efficacy Of Osimertinib

Objective:Investigate the relationship between the clinical features of patients with advanced NSCLC after the first generation EGFR-TKIs resistance and T790M mutation,the efficacy of osimertinib,to provide evidence for early prediction of the mutation status of T790M,early evaluation of the efficacy of osimertinib.Methods:Retrospectively collected clinical data of 52 patients who have experienced T790M mutation tissue detection with advanced NSCLC after the first generation EGFR-TKIs resistance(including gender,age,smoking history,clinical stage,EGFR initial mutation type,the first generation EGFR-TKIs type and PFS,serum CEA level);Patients with T790M mutations who received osimertinib were evaluated efficacy according to the RECIST 1.1evaluation criteria and were followed up by telephone or clinic;The correlation between the above clinical features and the T790M mutation status,the efficacy of osimertinib was analyzed.Results:1.A total of 52 patients were enrolled in this study,overall mutation rate of T790M was 48.1%;2.The EGFR initial mutation type and the PFS of the first generation EGFR-TKIs in patients with advanced NSCLC after the first generation EGFR-TKIs resistance are associated with the T790M mutation status.The T790M mutation rate was higher in advanced NSCLC patients whose EGFR initial mutation type is 19 exons or the PFS of the first generation EGFR-TKIs is more than 11 months(X~2 values were 7.530,4.914,P values were0.008,0.007,respectively).The logistic regression model suggests that the initial mutation type of EGFR and the PFS of the first generation EGFR-TKIs were independent factors affecting the T790M mutation of patients with advanced NSCLC after the first generation EGFR-TKIs resistance(OR=4.212,0.152;95%CI:1.257-18.081,0.038-0.604;P=0.008,0.007);3.There was no significant difference between the T790M mutation status and age,gender,smoking,clinical stage,the first generation EGFR-TKI drug type and serum CEA level in patients with advanced NSCLC after the first generation EGFR-TKIs resistance(P>0.05).4.There was no correlation between the efficacy of osimertinib in patients with advanced NSCLC with T790M mutation and the age,gender,smoking,clinical stage,EGFR initial mutation type the first generation EGFR-TKI drug type,PFS,and serum CEA level(P>0.05).Conclusion:1.The T790M mutation is the most common drug-resistant mutation in NSCLC patients with the first-generation EGFR-TKIs resistance;2.The type of EGFR initial mutation and the PFS of first-generation EGFR-TKIs in patients with advanced NSCLC after first-generation EGFR-TKIs resistance were correlated with T790M mutation status,and were independent influencing factors of T790M mutation status;3.The efficacy of osimertinib was not associated with age,gender,smoking,clinical stage,EGFR initial mutation type,type and PFS of first-generation EGFR-TKIs,serum CEA levels in patients with advanced NSCLC after first-generation EGFR-TKIs resistance.