Tumor immune microenvironment (TIME) analysis of stage I lung adenocarcinoma with micropapillary pattern.

Abstract

e20510 Background: Micropapillary is one of the most aggressive histologic subtypes of lung adenocarcinoma, which is considered a poor prognostic marker. Comprehensive analysis of tumor immune microenvironment (TIME) features of micropapillary of early invasive lung adenocarcinoma may provide better insight and facilitate the development of novel strategies for early detection and intervention. Methods: A total of 15 patients who underwent anatomical resection and were pathologically diagnosed with stage I micropapillary adenocarcinomas were included in this study. Gene expression profiles (GEPs) of tumor immune-related 289 genes were analyzed using NanoString nCounter. Differentially expressed genes(DEGs), estimation of TIME cell infiltration, and TIME signatures between micropapillary and non-micropapillary were assessed. Results: The number of micropapillary and non-micropapillary patients was 5 and 10. The comparison revealed CD69, IL6, CXCL8, CXCL2, POLR2A and so on were significantly upregulated in the micropapillary group compared with the non-micropapillary group, while HLA-DPA1, IFIT2, and other seven genes were down-regulated in the micropapillary group. These DEGs were mostly enriched in “positive regulation of cytokine production”， “T cell activation”， “receptor ligand activity，” and “signaling receptor activator activity” pathways according to GO enrichment analysis. The results of the KEGG analysis revealed that genes were significantly enriched in “IL-17 signaling pathway”, “TNF signaling pathway”, “cytokine-cytokine receptor interaction”, and so on. Meanwhile, different immune infiltration of the two groups was analyzed. Totally, there was a better TIME cell infiltration in the micropapillary group compared with the non-micropapillary group. Especially, the score of DCs and mast cells was significantly higher in micropapillary group. However, TIME signature scores were similar in both groups. Conclusions: Our study demonstrated that the TIME between micropapillary and non-micropapillary of stage I lung adenocarcinoma was different. Increased mast cells explained poor prognosis in lung adenocarcinoma with micropapillary pattern. A high level of DCs infiltration indicated that micropapillary adenocarcinoma might benefit from immunotherapy.