Detection of Five Solid Carcinomas Using Blood Circulating Proteins

When diagnosed in a metastatic stage cancer is mostly incurable making its early detection via biomarkers of immense clinical interest. Proteins circulating in blood are a preferred source of biomarkers for a wide range of cancers due to the ease and non-invasiveness of collection. Our approach to cancer biomarker discovery is based on the observation that proteomic changes in tumor tissue are remotely detectable as changes in the protein composition of blood plasma. To determine whether these changes in the plasma of patients are specific for their specific cancer or represent a response to cancer in general we performed a cross-tumor plasma proteomic study. Using a proteomic serum/plasma workflow consisting of the combined use of N-glycosite enrichment and SWATH mass spectrometry (SWATH-MS), we investigated 155 blood samples derived from cohorts of patients with carcinomas at a localized or locally advanced clinical stage, or from a matched control group. A quantitative comparison of the resulting N-glycosite profiles indicated that some biomarkers are common to several cancers, while others are highly specific for one cancer type.