PD-1 or PD-L1 co-localizes with immune cells for prediction of prognosis in non-small cell lung cancer.

Abstract

e21029 Background: A number of studies have shown that tumor cells expressing PD-L1 correlate with a better prognosis of immunotherapy in patients with non-small cell lung cancer(NSCLC). However, there were few studies on the immune cells that expressing PD-1 or PD-L1 affect the clinical outcome of patients with NSCLC. Therefore, further research is needed Methods: A total of 336 tumor tissues from patient with non-small cell lung cancer were collected and divided into two cohorts, discovery cohort (174 patients) and validation cohort (162 patients). We used multiplex IHC to identify and quantify CD8, CD57, CD68, CD163, PD-1 and PD-L1 positive rate in tumor tissues, and analyzed its relationship with clinical prognosis. Results: Both PD-1 and PD-L1 were detected on CD8+, CD57+, CD68+, and CD163+ immune cells, but the positive rate were different. PD-1 was higher on cytotoxic T cells (CD8+PD-1+) and PD-L1 was higher on macrophages and cytotoxic T cells (CD68+PD-L1+ and CD8+PD-L1+). By undifferentiated clustering analysis in discovery cohort, the survival rate of tumors with more immune cells expressing PD-1 or PD-L1 was worse. Univariate analysis using X-tile plots to generate the optimum cut off score for all features revealed that immune cells expressing PD-1 or PD-L1 were adverse factors of clinical prognosis of patients with NSCLC, and this result was also confirmed in the validation cohort. Conclusions: In 336 non-small cell lung cancer cases, the expression characteristics of PD-1 and PD-L1 on tumor-infiltrating immune cells were related to survival of patient. In this study, high level of PD-1 and PD-L1 expression on immune cells were associated with lower survival rate, and biomarker characteristics based on this analysis probably enables us to better guide clinical treatment