505P A dynamic proteomic signature for the prediction of incident lung cancer: A longitudinal analysis in the UK biobank cohort

outcome cluster in every dataset is defined by signatures of high immune population, high PD-L1, and low B-cells, all of which were confirmed at the protein level by mIF.It also shows an exclusion of epithelial T-cells visible in routine H&E.Spatially resolved transcriptomics reveals overexpression of stromal extracellular matrix programs, supporting this physical exclusion of T-cells from the tumour regions.Our findings suggest a key role for B-cells in tumour virulence and checkpoint inhibitor sensitivity, and we are now studying their broader influence on the immune microenvironment. Conclusions:We propose a robust new transcriptomic based classification of LUAD which defines 6 LUAD variants, each with key clinicopathological features, and which highlights the defining role of B-cells in tumour virulence.