Abstract: PD04-07
Sources of Funding: Supported by National Natural Science Foundation of China(Grand number 81572506)

Introduction

Renal cell carcinoma (RCC) is one of the most common urological tumors. The role of programmed cell death 1 ligand 1 (PD-L1) in RCCs in predicting outcome of the patients is yet unclear.

Methods

We analyzed the clinical and RNA-seq data of 522 kidney clear cell cancer (KIRC), 259 kidney papillary cell carcinoma (KIRP) and 66 kidney chromophobe (KICH) patients from The Cancer Genome Atlas (TCGA) database.

Results

In KIRC patients with high PD-L1 mRNA level and low PD-L1 mRNA level in tumors, the median overall survival periods were 45.0 and 37.1 months respectively (p=0.002). Multivariate Cox regression tests found that PD-L1 mRNA level in tumor was an independent predictor for overall survival status in KIRC patients (HR=0.7, 95% CI 0.5-0.9, p=0.007). However, no significant difference in overall survival status was found between high and low PD-L1 groups in KIRP and KICH cohorts.Gene-set enrichment analysis on the data from databases of TCGA and GSE53757 dataset in GEO showed that several pathways relating to immunological functions were activated in KIRCs with high PD-L1 mRNA expression, and glycolysis and epithelial-mesenchymal transition pathways relating to tumor progression and metastasis were up-regulated in KIRCs with low PD-L1 mRNA level.

Conclusions

In conclusion, higher PD-L1 mRNA level in KIRC tissues was associated with a favorable outcome due to the higher immunological responses in tumor tissues.

Funding

Supported by National Natural Science Foundation of China(Grand number 81572506)