Immune evolution from preneoplasia to invasive lung adenocarcinomas and underlying molecular features

Abstract

How anti-cancer immunity shapes early carcinogenesis of lung adenocarcinoma (ADC) is unknown. We characterized immune contexture of invasive lung ADC and its precursors by transcriptomic immune profiling, T cell receptor (TCR) sequencing and multiplex immunofluorescence. Our results demonstrated that anti-tumor immunity evolved as a continuum from lung preneoplasia, to preinvasive ADC, minimally-invasive ADC and frankly invasive lung ADC with a gradually less effective and more intensely regulated immune response including down-regulation of immune-activation pathways, up-regulation of immunosuppressive pathways, higher infiltration of CD4+ T cells, lower infiltration of CD8+ T cells, decreased T cell clonality, and lower frequencies of top T cell clones in later stages. Driver mutations, HLA loss, chromosomal copy number aberrations and DNA methylation changes may collectively impinge host immune responses and facilitate immune evasion as a potential mechanism underlying outgrowth of the most fit subclones in preneoplasia into dominant clones in invasive ADC. SIGNIFICANCEThere has been a drastic increase in the detection of lung nodules, many of which are lung ADC precursors. The management of these lung nodules is controversial. We discovered that immune activation and evasion have started at preneoplastic stage and lung ADC precursors may exhibit an overall better-preserved anti-tumor immune contexture suggesting therapeutic strategies reprograming the immune microenvironment in patients with lung ADC precursors prior to further immunosuppression in invasive lung cancers may be beneficial. These findings have served as the critical scientific rationale for our immunoprevention clinical trial IMPRINT-Lung (NCT03634241) recruiting individuals diagnosed with lung nodules at high risk developing invasive lung cancers.