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

SUMMARY BACKGROUND & AIMS Esophageal adenocarcinoma (EAC) is thought to develop from asymptomatic Barrett’s 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. Abbreviations AAL Aleuria aurantia lectin %CV % Co-efficient of variation AUROC Area under receiver operating characteristics curve BE Barrett’s esophagus BE-HGD Barrett’s esophagus with high-grade dysplasia BE-ID Barrett’s esophagus which is indefinite for dysplasia BE-LGD Barrett’s esophagus with low-grade dysplasia BMI Body mass index C1QB Complement C1q subcomponent subunit B C2 Complement C2 C3 Complement C3 C4B Complement C4-B C4BPA C4b-binding protein alpha chain C4BPB C4b-binding protein beta chain C9 Complement component C9 CFB Complement factor B CFI Complement factor I CI Confidence interval CP Ceruloplasmin EAC Esophageal adenocarcinoma EPHA Erythroagglutinin from Phaseolus vulgaris FFPE Formalin-fixed, paraffin-embedded GERD Gastroesophageal reflux disease GSN Gelsolin JAC Jacalin from Artocarpus integrifolia LeMBA Lectin magnetic bead array MRM-MS Multiple reaction monitoring-mass spectrometry NPL Narcissus pseudonarcissus lectin NSE Non-specialized epithelium OR Odds ratio PGLYRP2 N-acetylmuramoyl-L-alanine amidase PON1 Serum paraoxonase/arylesterase 1 PON3 Serum paraoxonase/lactonase 3 RBP4 Retinol-binding protein 4 SERPINA4 Kallistatin SIS Stable isotope-labeled internal standard