Comprehensive analysis of PD-L1 expression, tumor-infiltrating lymphocytes, and tumor microenvironment in LUAD: differences between Asians and Caucasians

Fenglong Bie,Moyan Zhang,Ruochuan Zang,Peng Song,Guangyu Bai,Lei Liu,Shugeng Gao,Nan Sun,Yue Peng,Bolun Zhou,He Tian

doi:10.1186/s13148-021-01221-3

Abstract

BackgroundsThe characteristics of programmed cell death protein-1 (PD-L1) expression, tumor-infiltrating lymphocytes (TILs), and tumor microenvironment (TME) in lung adenocarcinoma (LUAD) patients are closely related to immunotherapy, and there are differences between Asians and Caucasians.MethodsAcquire the transcriptome data of the Cancer Genome Atlas and Chinese LUAD patients. R software was used to analyze the differential expression of genes, prognosis, and gene function. Use CIBERSORT for TIL-related analysis and ESTIMATE for TME-related analysis.ResultsThe expression of PD-L1 in tumor tissues of Caucasian LUAD patients was lower than that in normal tissues, while there was no significant difference in Asians. There was no statistical difference between PD-L1 expression and prognosis. The composition of TILs between Caucasian and Asian LUAD patients was quite different. There was no correlation between TILs and prognosis in Caucasians. However, the higher content of resting mast cells indicated a better prognosis in Asians. The Caucasian patients with higher immune and estimate scores had a better prognosis (p = 0.021, p = 0.025). However, the Asian patients with a higher estimate score had a worse prognosis (p = 0.024). The high expression of COL5A2 (p = 0.046, p = 0.027) and NOX4 (p = 0.020, p = 0.019) were both associated with the poor prognosis in Caucasians and Asians.ConclusionThere are many differences in the characteristics of PD-L1 expression, TILs, and TME between Caucasian and Asian LUAD patients. This provides a certain hint for the selection of specific immunotherapy strategies separately for Caucasian and Asian LUAD patients.

Highlights

Lung cancer is the cancer with the highest fatality rate and the second-highest incidence rate in the world [1, 2]
Many studies on immune checkpoint inhibitors (ICIs) therapy are based on Western databases such as the Cancer Genome Atlas (TCGA), and there are few studies comparing the differences between Asians and Caucasians
This study focused on comparing the differences between Caucasians and Asians on the characteristics of PD-L1 expression, tumor-infiltrating lymphocytes (TILs), and tumor microenvironment (TME) related to immunotherapy in lung adenocarcinoma (LUAD)

Summary

Introduction

Lung cancer is the cancer with the highest fatality rate and the second-highest incidence rate in the world [1, 2]. The main pathological types of NSCLC are lung adenocarcinoma. (LUAD), lung squamous cell carcinoma (LUSC), and large cell carcinoma. The proportion of LUAD is increasing, and it has become the most common pathological type of NSCLC [4]. Many studies on immune checkpoint inhibitors (ICIs) therapy are based on Western databases such as the Cancer Genome Atlas (TCGA), and there are few studies comparing the differences between Asians and Caucasians. This study took LUAD as the research disease, focusing on the analysis of immunotherapy-related programmed death-ligand 1 (PD-L1, called CD274) expression, tumor-infiltrating lymphocytes (TILs), and tumor microenvironment (TME) characteristics between Asians and Caucasians

Methods

Results

Conclusion