Serum glycoprotein biomarker validation for esophageal adenocarcinoma and application to Barrett's surveillance

BACKGROUND u0026 AIMS: Esophageal adenocarcinoma (EAC) is thought to develop from asymptomatic Barrett9s esophagus (BE) with a low annual rate of conversion. Current endoscopy surveillance for BE patients is probably not cost-effective. Previously, we discovered serum glycoprotein biomarker candidates which could discriminate BE patients from EAC. Here, we aimed to validate candidate serum glycoprotein biomarkers in independent cohorts, and to develop a biomarker panel for BE surveillance. METHODS: Serum glycoprotein biomarker candidates were measured in 301 serum samples collected from Australia (4 states) and USA (1 clinic) using lectin magnetic bead array (LeMBA) coupled multiple reaction monitoring mass spectrometry (MRM-MS). The area under receiver operating characteristic curve was calculated as a measure of discrimination, and multivariate recursive partitioning was used to formulate a multi-marker panel for BE surveillance. RESULTS: Different glycoforms of complement C9 (C9), gelsolin (GSN), serum paraoxonase/arylesterase 1 (PON1) and serum paraoxonase/lactonase 3 (PON3) were validated as diagnostic glycoprotein biomarker candidates for EAC across both cohorts. A panel of 10 serum glycoproteins accurately discriminated BE patients not requiring intervention [BE+/- low grade dysplasia] from those requiring intervention [BE with high grade dysplasia (BE-HGD) or EAC]. Tissue expression of C9 was found to be induced in BE, dysplastic BE and EAC. In longitudinal samples from subjects that have progressed towards EAC, levels of serum C9 glycoforms were increased with disease progression. CONCLUSIONS: Further prospective clinical validation of the confirmed biomarker candidates in a large cohort is warranted. A first-line BE surveillance blood test may be developed based on these findings.