Clinical utility of high-throughput glycome analysis in patients with pancreatic cancer

Background: Most of the glycan changes reported in cancers were based on the examinations of a small number of patients or particular proteins. The aim of this study was to determine the changes of the serum N-glycan profile comprehensively in a large number of pancreatic cancer patients and investigate its clinical utility. Methods: Glycan levels in the serum of 92 pancreatic cancer patients and 243 healthy volunteers (HLT) were examined by comprehensive quantitative high-throughput glycome analysis and were compared with clinical parameters. Results: Out of 66 glycans detected, 15 were differentially expressed in pancreatic cancer, and 10 out of the 15 glycans were significantly up-regulated in cases with distant metastasis. There was a clear increase in overall expression of serum glycans, especially highly-branched glycans with fucose moieties, in pancreatic cancer. Among these 15 glycans, a tri-antennary complex type glycan (m/z 3195) showed the highest area under the receiver operating characteristic curve (AUROC = 0.799) for the diagnosis of pancreatic cancer. The ratio of pairs of glycans on the same path of the biosynthesis pathway (m/z 3195/1914) was found to be significantly higher in pancreatic cancer than in HLT (median = 1.11 and 0.41, respectively; p < 0.0001, AUROC = 0.831). For this pair ratio, the hazard ratio for survival (2.60, 95 % CI = 1.44-4.79) was higher than that of any single glycan and 1-year survival of patients with a high and low ratio was 36.9 and 69.2 %, respectively, (p = 0.001). Conclusions: Comprehensive glycome analysis can be used to know the presence of pancreatic cancer, distant metastasis, and patient prognosis, simultaneously.