Study On Survival And Prognosis Of Brain Metastasis In Elderly Patients With Non-Small Cell Lung Cancer

According to relevant data,lung cancer is one of the most common cancers in the world,especially in China,the morbidity and mortality of primary lung cancer are the highest,and non-small cell lung cancer is the main type of lung cancer.accounting for about 85% of the cases,the brain is a common metastatic site of advanced non-small cell lung cancer,which usually means that the survival prognosis is poor,especially for elderly patients.The immunity is low and the risk of death is higher.The study of brain metastasis of elderly non-small cell lung cancer can better determine the risk stratification and develop appropriate treatment,which has practical significance and application value to predict the survival probability of patients and reduce the risk of death.This paper mainly analyzes the data from the American cancer database SEER.Firstly,the survival curves of population,age,sex,metastasis,T stage,N stage,pathological type and treatment mode were described by Kmurm estimation.Secondly,the independent prognostic factors were determined by univariate Cox model analysis,and then the multi-factor Cox proportional hazard regression model was constructed by stepwise regression.Similarly,in the case of considering competitive events,firstly,Nelson-Aalen cumulative risk curve(CIF)is used to analyze the differences of risk functions among different groups of variables,and then a single factor competitive risk model is established to determine the independent prognostic variables that affect survival time and outcome,based on which a multi-factor competitive risk model is constructed.In the model of the application of neural network,all variables are included in the analysis,and the prediction model is constructed by setting hidden layers and nodes.The influencing variables determined in Cox proportional hazard regression model are age,sex,metastatic part,T stage,N stage and pathological type.When considering competitive events,the influencing variables are: age,sex,metastatic part,T stage,N stage,pathological type.By comparing the ROC curve and calibration curve of the three prediction models,the results show that the overall competitive risk model is optimal.Finally,the survival probability is visualized by building a line map.The risk of extracranial metastasis was further stratified based on the above competing risk model.Three modes of extracranial metastasis were identified: MA(no metastasis in liver,bone and lung),MB(no metastasis in liver)and MC(metastasis in liver).There was a significant difference in survival probability among patients with MA,MB and MC(SHR=1.13,95%CI: 1.05-1.21,p<0.01;SHR=1.46,95%CI: 1.34-1.60,p< 0.0l).Secondly,through subgroup analysis and interaction test,it was found that chemotherapy was the best.Then the survival and prognosis prediction model of patients at 6,12 and 18 months was constructed,and the ROC curve,calibration curve and decision curve were analyzed to judge the accuracy and fitness of the model.Finally,reasonable suggestions are provided for the above research conclusions.