ASCO-SITC 2018: Study Sheds Light on Immune Microenvironment of Lung Tumors
According to research findings presented at the American Society of Clinical Oncology–Society for Immunotherapy of Cancer (ASCO-SITC) Clinical Immuno-Oncology Symposium (Abstract 140) in San Francisco, greater T-cell diversity in the periphery may prove to be linked to better overall survival in patients with non–small cell lung cancer (NSCLC) compared with those who have a more normal lung/tumor T-cell repertoire. Alexandre Reuben, PhD, of the MD Anderson Cancer Center in Houston, and colleagues found distinct phenotypes between normal lung and NSCLC tumors, suggesting possible differences in the ongoing immune response in different regions of the lungs.
Sequencing of the CDR3 variable region of the beta chain of the T-cell receptor as well as whole-exome sequencing on peripheral blood, normal lung, and tumor cells were performed on 235 patients with NSCLC. The immune microenvironment was further analyzed in 10 patients with paired normal lung and tumor.
Greater T-cell clonality was found in the normal lung than in the tumor in the majority of patients (89%). The investigators also confirmed marked differences in the immune microenvironment between normal lung and tumor, including higher frequency of VISTA-positive antigen-presenting cells in the tumor.
“These results suggest that a substantial proportion of infiltrating T cells in NSCLC tumors may be lung-resident T cells associated with response to environmental factors,” Dr. Reuben and colleagues concluded.