Tumor-infiltrating CD45RO memory cells correlate with favorable prognosis in patients with lung adenocarcinoma.

BACKGROUND

The present study aimed to investigate the association of CD45RO, CD8, CCR7 and FOXP3 tumor-infiltrating lymphocytes (TILs) with the clinicopathological features as well as survival of patients with lung adenocarcinoma.

METHODS

Ninety patients with lung adenocarcinoma who underwent surgery were recruited in the present study. Lung adenocarcinoma tissues and paired adjacent lung tissues were obtained from all participants, and immunohistochemistry was performed to detect the expression of CD45RO, CD8, CCR7 and FOXP3. After multiplying the staining intensity score by the labeling frequency score, the immunohistochemical results were divided into three groups: TILs low, TILs intermediate and TILs high.

RESULTS

CD45RO, CD8 and CCR7 infiltrating lymphocytes were markedly increased in lung adenocarcinoma (all P<0.001) while FOXP3 infiltrating lymphocytes were reduced (P<0.001) compared with than in adjacent tissues. CD45RO TILs were negatively associated with tumor size (P=0.002), lymph node metastasis (P<0.001) and TNM stage (P<0.001). CD8 TILs were also negatively correlated with lymph node metastasis (P=0.016). Kaplan-Meier curve analysis revealed that CD45RO TILs were positively associated with longer disease-free survival (DFS) (P<0.001) and overall survival (OS) (P<0.001). Univariate and multivariate Cox's proportional hazards regression confirmed that CD45RO TILs (high) independently predicted longer DFS (P=0.002) and OS (P=0.009).

CONCLUSIONS

The present study demonstrates that CD45RO TILs are negatively correlated with tumor size, lymph node metastasis and TNM stage and that CD45RO TILs (high) can be regarded as a novel and promising biomarker for prolonged DFS and OS in lung adenocarcinoma patients.