Multiomics analysis reveals high-immune infiltration in tumor-adjacent lung tissues affects the prognosis of stage I NSCLC.

Abstract

8540 Background: Along with the wide application of low-dose spiral CT in lung cancer screening, a large number of resectable patients with lung cancer are identified, especially stage I Non-Small Cell Lung Cancer (NSCLC). However, their prognosis varies greatly and 5-year recurrence rate of stage I NSCLC is around 30%. Therefore, it is crucial to explore the potential mechanism of recurrence of early NSCLC. Methods: Eighty-seven patients with stage I NSCLC were enrolled from April 2008 to July 2015, including 79 squamous carcinoma and 28 adenocarcinoma. Frozen tumor tissues and paired tumor-adjacent lung tissues were collected to employ targeted panel sequencing, RNA sequencing and TCR repertoire sequencing. Results: Ninety-five non-silent mutations were detected in tumor-adjacent lung tissues with a median tumor mutation burden of 1.5/Mb, significantly lower than that in tumor tissues (11/Mb), p < 0.05. 42 mutations were specifically detected in the adjacent normal tissues, enriching in the immune response pathways. Comparing with paired tumors, tumor-adjacent lung tissues were found more favorable immune infiltration including higher immune cell activity like CD8+ T cell (0.50 vs 0.43, p < 0.0001), up-regulated immune-associated pathways, higher TCR clonality (0.19 vs 0.18, p < 0.05), less loss of heterozygosity (LOH) of human leukocyte antigen (HLA) (6.25% vs 50%, p < 0.0001) and observed predicted neoantigens expression (1 vs 128, p < 0.01). However, more shared viral-associated TCRs in tumor and tumor-adjacent tissues were found using the GLIPH algorithm. Prognostic analysis showed patients with higher overlap of TCR in tumors and tumor-adjacent lung tissues were prone to recur in five years. Furthermore, patients with higher immune infiltration in tumor-adjacent lung tissues had favorable outcomes than those with lower immune infiltration (HR: 0.37 for DFS, p < 0.05, HR: 0.31 for OS, p < 0.05), irrelevant of the infiltration level in tumor tissues. Conclusions: Immune microenvironment in tumor-adjacent lung tissues plays important roles in progress of stage I NSCLC.