Peripheral memory and naïve T cells in non-small cell lung cancer patients with lung metastases undergoing stereotactic body radiotherapy: predictors of early tumor response

Chao Liu†View ORCID ID profile,
Qinyong Hu†,
Bin Xu,
Xiaoyu Hu,
Huichao Su,
Qian Li,
Xiaoling ZhangEmail author,
Jinbo YueEmail author and
Jinming YuEmail author

†Contributed equally

Cancer Cell International201919:121

https://doi.org/10.1186/s12935-019-0839-5

Received: 26 February 2019
Accepted: 25 April 2019
Published: 7 May 2019

Abstract

Background

Further analysis of phase I trial of the KEYNOTE-001 has shown that previous radiotherapy improves the outcomes of patients with advanced non-small cell lung cancer (NSCLC) who received pembrolizumab treatment, possibly explained by the radiation-induced specific anti-cancer immunity with a memory effect. In this study, we aimed to investigate the peripheral memory and naïve T cells as predictors of early response in lung metastases post-stereotactic body radiotherapy (SBRT).

Methods

Sixty-six lung metastases patients with NSCLC who received SBRT were enrolled in this study. Analyses of peripheral memory CD4+ T, memory CD8+ T, naive CD4+ T, and naive CD8+ T in NSCLC patients were performed by flow cytometry. Evaluations of the link between immune cells and early radiation response a month after SBRT were carried out via logistic regression analyses.

Results

Higher levels of memory CD4+ T, memory CD8+ T, and lower levels of naïve CD4+ T, CD4+ naïve/memory ratio, and CD8+ naïve/memory ratio were shown in responders compared with non-responders (all P < 0.05). Logistic regression analyses of univariate and multivariate revealed that peripheral memory CD4+ T (OR: 0.14, 95% CI 0.04–0.50, P = 0.003; OR: 0.17, 95% CI 0.05–0.66, P = 0.010), memory CD8+ T (OR: 0.11, 95% CI 0.01–0.87, P = 0.037; OR: 0.11, 95% CI 0.01–0.97, P = 0.047), naïve CD4+ T (OR: 16.25, 95% CI 3.17–83.13, P = 0.001; OR: 12.67, 95% CI 2.26–71.18, P = 0.004) and CD4+ naïve/memory ratio (OR: 11.27, 95% CI 2.67–47.58, P = 0.001; OR: 8.50, 95% CI 1.90–38.14, P = 0.005) were independent predictors for tumor response to SBRT in the lung metastases of NSCLC patients.

Conclusions

The tumor response of lung metastases a month after SBRT independently correlated with peripheral memory CD4+ T, memory CD8+ T, naïve CD4+ T, and CD4+ naïve/memory ratio. These findings could be helpful in incorporating additional treatments to improve clinical outcomes in the case of poor responders.