Risk Factors Analysis Of Leptomeningeal Metastasis In EGFR Mutation Positive Advanced Non-small Cell Lung Cancer Patients After TKIs Treatment

Background and objective:It has been shown that epidermal growth factor receptor(EGFR)mutated positive non-small cell lung cancer(NSCLC)patients can benefit from tyrosine kinase inhibitors(TKIs)treatment.However,TKIs resistance is inevitable.Currently,leptomeningeal metastasis(LM)after TKIs resistance has attracted increasing attention.This study aimed to construct a nomogram model to predict the risk of LM in EGFR-mutated positive advanced NSCLC patients after receiving TKIs treatment.Methods:This study conducted a retrospective analysis of advanced EGFR-mutant NSCLC patients who received first-line TKIs treatment between January 1,2014,and May 31,2021.The patients were randomly divided into a training set and a validation set in a 7:3 ratio.Univariate and multivariate Cox regression analyses were performed to identify significant predictors related to LM.Factors with p<0.05 in the multivariate analysis were used to construct nomogram,and the nomogram was evaluated by concordance index(C-index),ROC curve and calibration curve.Results:At the end of the follow-up on October 31,2022,55 patients developed LM,and seven factors associated with the risk of LM were ultimately confirmed: initial diagnosis of brain metastasis,bone metastasis,liver metastasis,metastatic status,gene mutation type,previous use of Osimertinib and progression-free survival(PFS)of first-line TKIs treatment.The C-indexes of the nomogram constructed in the training and validation sets were 0.833 [95% confidence interval(CI)0.782-0.884]and 0.875(95% CI 0.793-0.922),respectively,indicating good discrimination of the model.The calibration curve showed good consistency between the predicted and observed results of the nomogram.Conclusion:This study developed a nomogram model to predict the risk of LM in EGFR mutation-positive advanced NSCLC patients after receiving TKIs treatment.The nomogram can help clinicians identify high-risk individuals for LM occurrence,thereby developing intervention and treatment strategies.