Here, we present an in-depth proteomic profiling of pre-diagnostic plasma samples from 114 individuals with suspected lung cancer, including 57 patients diagnosed with stage III-IV lung adenocarcinoma (LUAD) and 57 non-cancer controls. Plasma samples were depleted of high-abundant proteins, and proteomic analysis was performed using high-resolution isoelectric focusing (HiRIEF) coupled with liquid chromatography tandem mass spectrometry (LC-MS/MS), with relative quantification by isobaric tandem mass tags (TMT16-plex).