Elevated Serum Levels of Circulating Immunoinflammation-Related Protein Complexes Are Associated with Cancer

Disease-specific immune response-related protein complexes in the bloodstream are associated with disease status. We used proteomic technologies to screen novel circulating immunoinflammation-related protein complexes (IIRPCs) and to evaluate their diagnostic accuracy. The discovery study included 96 gastric cancer patients and 83 healthy controls and was designed to isolate and identify the IIRPCs. Then an independent validation study including 1366 patients with lung, colorectal, pancreatic, gastric, or thyroid cancer, 141 patients with other types of cancer, 376 patients with benign lung, colorectal, pancreatic, gastric, or thyroid diseases, and 3707 healthy controls was performed. We observed seven major patterns of the IIRPCs and confirmed the IIRPCs as personalized biomarkers of cancers. The levels of the IIRPCs were significantly increased in cancer patients compared with controls and benign patients (p < 0.0001). Each of the IIRPCs (a2 to a4, a6, a7, and b3 to 135) shows excellent discriminating power for lung, colorectal, pancreatic, and gastric cancer, with under the receiver operating characteristic curves (AUCs) from 0.95 to 0.99 (95% CIs 0.91-1.00), and for thyroid cancer, with the AUCs from 0.87 to 0.96 (95% CIs 0.80-0.98). The IIRPCs can be used as a novel type of broad-spectrum and supramolecular biomarker for personalized cancer diagnosis.