Analysis Of The Factors Influencing The Survival Difference In The Treatment Of T790M Positive Lung Adenocarcinoma With Osimertinib

Objective(s):By collecting existing clinical data for real-world research,to analyze the relationship between the clinical characteristics and survival of patients who had received the third-generation EGFR-TKI osimertinib targeted therapy after T790M resistant mutation was found in patients who had received the first-generation epidermal growth factor receptor-tyrosine kinase inhibitors(EGFR-TKI)treatment,and to explore the factors of good prognosis of osimertinib.Methods:A retrospective analysis of 298 patients with T790M resistant mutations after progression of the first-generation EGFR-TKI therapy from January,2014 to January,2021 in Yunnan Cancer Hospital was conducted,clinical data of patients with lung adenocarcinoma treated with the third-genreration EGFR-TKI osimertinib monotherapy.Patients return to the hospital for follow-up visits in 1-3 months,and comprehensively evaluate the curative effect based on clinical and imaging manifestations.During the treatment period,patients should complete a chest CT/MRI examination at least once every 1-3 months,cranial MRI and whole body bone scan were performed at least once every 6-12 months,and the curative effect was evaluated according to the response evaluation criteria in solid tumorsl.1(RECIST1.1).Statistical analysis was performed with SPSS 25.0 software,Kaplan-Meier method was used for survival analysis,Log-Rank test was used for univariate survival prognosis analysis,and COX proportional model was used for multivariate survival analysis,use the GraphPad Prism 8.0.2 software to plot the forest.Results:1.Among 298 patients with lung adenocarcinoma treated with osimertinib who had a T790M resistance mutation detected by secondary genetic testing,226 patients developed resistance again.2.Univariate survival analysis showed that KPS score,type of primary EGFR mutation,liver metastasis,number of distant metastatic organs and previous operation may be the influencing factors of progression free survival(PFS)difference of patients receiving osimertinib,while KPS score,brain metastasis,number of distant metastatic organs,previous operation,tumor markers CEA,CA125,CA199 and the largest diameter of primary tumor may be the influencing factors of overall survival(OS)difference of patients receiving osimertinib,the difference was statistically significant(P<0.05).Multivariate survival analysis showed that KPS score and EGFR mutation type at initial treatment may be indqpendent prognostic factors affecting osimertinib PFS,while CA125 may be independent prognostic factor affecting osimertinib OS(P<0.05).3.Patients who had previously received concomitant therapy were given osimertinib,univariate survival analysis showed that the efficacy of radiotherapy and chemotherapy in patients receiving previous radiotherapy and chemotherapy treatment may be the influencing factor of PFS difference of patients receiving osimertinib,while the efficacy of chemotherapy may be the influencing factor of PFS difference of patients receiving osimertinib,the difference was statistically significant(P<0.05).Multifactor survival analysis showed that radiotherapy efficacy may be an independent prognostic factor of osimertinib PFS(P<0.05).Conclusion(s):Patients with T790M(+)lung adenocarcinoma treated with osimertinib,KPS score,and type of primary EGFR mutation may be independent prognostic factors affecting PFS,and the tumor marker CA125 may be an independent prognostic factor affecting OS,patients with a KPS score≥80 and a classic EGFR mutation may have a longer PFS,and patients with a tumor marker CA125<30.5 KU/L may have a longer OS.For patients who have previously received radiotherapy,radiotherapy efficacy may be an independent prognostic factor for PFS in patients treated with osimertinib,radiotherapy efficacy is positively associated with PFS in patients treated with osimeitinib in the posterior line.