PFAA profiling of patients with cancers. Schematic procedures of PFAA screening (A) and PFAA profile alterations in 117 cancer patients including 56 GC, 28 BC and 33 TC, compared to 137 HCs (B) are presented. Colored cells indicated levels of amino acids increased in cancer patients at p < 0.001 (dark red), p < 0.05 (pink), decreased in cancer patients at p < 0.001 (dark green), p < 0.01(green) and p < 0.05 (light green), respectively. PLS-DA scores plots showed a separation between control subjects (black) and cancer patients (red) in GC group (C), BC group (D) and TC group (E). For GC group, R2 = 0.852, Q2 = 0.837; for BC group, R2 = 0.786, Q2 = 0.727; for TC group, R2 = 0.792, Q2 = 0.761. Altered amino acid profiles of GC patients at early and advanced tumor stages are presented (F). The axes show the concentrations (μM) of each amino acid for discriminating relative early stage from advanced stage. Blue line stands for PFAAs of GC patients at stage 0-III, red line for PFAA of GC patients at stage IV. NEAAs: non-essential amino acids, EAAs: essential amino acids, BCAAs: branched-chain amino acids, GAAs: glucogenic amino acids, TAAs: total amino acids, GC: gastric cancer, BC: breast cancer, TC: thyroid cancer, HC: healthy control.