The Expression And Prognostic Significance Of Tumor-infiltrating CD8+T Cells And β-catenin In Non-small Cell Lung Cancer

PurposeLung cancer is a kind of malignant tumor with the highest morbidity and mortality in China and non-small cell lung cancer(NSCLC)accounts for about 85%of primary lung cancer.Tumor immune microenvironment plays an important role in the development of NSCLC and other malignant tumors,and tumor-infiltrating CD8+T cells are the main anti-tumor immune effector cells.Studies illustrated that there was a close correlation between the quantity and localization(cancer nest and stroma)of infiltrating CD8+ T cells with chemoradiotherapeutic efficacy and prognosis of tumor patients.Immunotherapy has become the promising field in NSCLC therapy and it is confirmed that tumor-infiltrating CD8+ T cells are indispensable for effective anti-PD-1/PD-L1 immunotherapy.Therefore,it is of great research value and clinical significance to investigate the factors that regulate tumor-infiltrating CD8+ T cells.As one of the classic signaling pathways,Wnt/p-catenin pathway plays a vital role in some physiological processes such as hematopoietic stem cell renewing and lymphocyte development and cancer processes involving oncogenesis,invasion and metastasis,and drug resistance,but the relationship between Wnt/p-catenin pathway and tumor-infiltrating CD8+ T cells in NSCLC remains unclear.This study detected tumor-infiltrating CD8+ T cells and(3-catenin expression in pathological tissues of NSCLC patients and analyzed their correlation and prognosis significance in NSCLC patients with statistical methods,which aims to provide the evidence for regulatory mechanism in tumor-infiltrating CD8+ T cells in NSCLC,and may become the predictive marker for the prognosis of NSCLC patients.MethodsA total of 88 patients with non-small cell lung cancer were enrolled according to inclusion and exclusion criteria,and the clinicopathological data were followed up and collected.The expression of CD8 and β-catenin was detected with immunohistochemistry in tumor pathological tissues.Chi-square test and rank sum test were applied to analyze the respective correlation of tumor-infiltrating CD8+ T cells and β-catenin expression with clinical pathological characteristics of patients.Spearman test analyzed the correlation between tumor-infiltrating CD8+ T cell number and P-catenin expression scores.Survival analysis of the patients was conducted by Kaplian-Meier curves.Univariate and multivariate analysis models(the Log Rank test)were performed for the factors affecting the survival prognosis of NSCLC patients.Results1.CD8+ T cells were both detected in cancer nest and stroma,and the mean number in nest was 36.86±2.31 per high power field(HPF)with 29.49±1.72/HPF in stroma,and their quantities were positively correlated(r=0.755,p<0.001).The statistical analysis of clinicopathological factors showed that the earlier TNM stage of patients,the more tumor-infiltrating CD8+ T cells(p<0.001).2.β-catenin was mainly expressed in tumor cell membrane/cytoplasm with 67.0%expression positive rate.The correlation analysis of patients with clinical pathologic factors showed that the β-catenin expression was negatively related to TNM staging of patients(p = 0.013).3.There was a correlation between tumor-infiltrating CD8+ T cells andβ-catenin expression in cancer cells.The higher number of CD8+ T cells in the cancer nest was in line with less β-catenin expression(r=-0.678,p<0.001);CD8+ T cell number in cancer stroma was also negatively correlated with β-catenin expression(r=-0.518,p<0.001).4.In the survival analysis of overall survival(OS)in stage Ⅰ to Ⅳ patients,the patients in CD8+ T cell high-infiltrating group in cancer nest owned significantly prolonged OS(p<0.001),and the OS of high-infiltration group in stroma was also significantly better than that in low-infiltration group(p<0.001);NSCLC patients with positive P-catenin expression had worse survival outcomes(positive group OS vs negative group OS,p=0.001).5.Stage Ⅰ-Ⅲ patients all underwent surgical treatment and their survival analysis indicated that the OS of patients with high-infiltrating CD8+ T cells in cancer nest was extended compared with low-infiltrating group(p = 0.005)and CD8+ T cell number in stroma also suggested better OS(p = 0.022);The disease-free survival(DFS)analysis of the patients showed that DFS in high-infiltrating CD8+ T cells in cancer nest and stroma were both superior to low-infiltrating group(nest p=0.019,stroma p=0.037).NSCLC patients with positive β-catenin possessed poorer survival prognosis(positive group OS vs negative group OS,p=0.019;positive group DFS vs negative group DFS,p=0.018).6.COX univariate survival analysis model revealed that tumor-infiltrating CD8+ T cells in cancer nest and stroma,β-catenin expression and TNM stage were correlated with OS of stage Ⅰ-Ⅳ patients and OS and DFS of stage Ⅰ-Ⅲ patients.The variables above were included into COX multivariate analysis model and the results showed that β-catenin expression level(p=0.047)and TNM staging(p=0.016)were independent prognostic factors for OS in stage Ⅰ-Ⅳ patients but not for OS and DFS in stage Ⅰ-Ⅲ patients.Conclusion1.CD8+ T cells were detected both in cancer nest and stroma and their quantities were positively correlated.The earlier TNM stage of patients indicated more tumor-infiltrating CD8+ T cells,β-catenin was mainly expressed in tumor cell membrane/cytoplasm and later TNM stage patients owned higher β-catenin expression.2.Stage Ⅰ-Ⅳ patients with high-infiltrating CD8+ T cells in cancer nest and stroma had longer OS than low-infiltrating group and stage Ⅰ-Ⅲ patients in high-infiltrating group also possessed longer OS and DFS.The patients with positiveβ-catenin expression owned poor survival prognosis including shorter OS in stageⅠ-Ⅳ and shorter OS and DFS in stage Ⅰ-Ⅲ patients.3.β-catenin expression in cancer cells was negatively correlated with the infiltrating number of CD8+ T cells in cancer nest and stroma respectively,suggesting that β-catenin may be the factor affecting the infiltration of CD8+ T cells.β-catenin expression level was an independent prognostic factor of OS in stage I-IV patients,which can be used to predict the survival prognosis of NSCLC patients.