The Infiltration Pattern Of Immune Cells In The Tumor Microenvironment Of Bladder Cancer And Its Clinical Significance

Background and purpose:Bladder cancer is the most common malignant tumor of the genitourinary system in China.In addition to BCG bladder perfusion therapy,several PD-1/PD-L1 inhibitors have been approved for bladder cancer in recent years.PD-1/PD-L1 inhibitors mainly make an effect by regulating the function of CD8+ T cells in Tumor Microenvironment(TME),and its efficacy is also affected by TME.Therefore,the research on the TME of bladder cancer has been paid more attention.Based on the TCGA public dataset,the purpose of our study was to explore the relationship between the infiltration pattern of immune cells in the TME of bladder cancer and the clinical characteristics,pathological stage and prognosis of these patients.Method:Based the CIBERSORT algorithm,we analyzed the infiltration patterns of a total 22 immune cell types in 406 patients with bladder cancer.The correlation between expression levels of 22 immune cells and pathological stage was analyzed by Wilcoxon test.The correlation between expression levels of 22 immune cells,clinicopathological features(such as age,sex,stage)and overall survival(OS)was evaluated by kaplan-meier log-rank test and COX regression model.Result:The distribution of M2,M0 macrophages,resting CD4 memory T cells,and CD8 T cells was more abundant in tissues of 406 patients with bladder cancer,accounting for 12.8%,12.6%,12.5%,and 10.8%,respectively.With the increase of clinical stage,level of CD8 T cells,follicular helper T cells,regulatory T cells,resting dendritic cells,activated dendritic cells gradually decreased,while M0 and M2 macrophages gradually increased.Higher level of activated CD4 memory T cells,CD8 T cells and resting dendritic cells have longer survival,while M0 macrophage was negatively correlated with OS.In addition,multivariate analysis found that age,TNM stage and CD8+ T cell level were independent prognostic factors affecting OS in patients with bladder cancer.Conclusion:The infiltration pattern of immune cells in TME in patients with bladder cancer is related to clinical stage.The CD8+ T cells is an independent prognostic factor affecting OS in these patients.The study suggests that increasing the number and function of CD8+ T cells in TME of bladder cancer and choosing treatment according to type of immune cell in TME may bring greater clinical benefits to these patients.