A targeted glycoproteomic approach identifies cadherin-5 as a novel biomarker of metastatic breast cancer

Highlights ► HPA binding breast cancer serum proteins underwent proteomic identification. ► Pregnancy zone protein, polymeric immunoglobulin receptor and cadherin-5 emerged as potential markers of metastatic breast cancer. ► Proteomic analysis was verified by ELISAs. The cadherin-5 ELISA discriminated recurrent breast cancers from those with no sign of recurrence. ► Analysis of cadherin-5 glycosylation also showed a significantdifference between the two sample groups. ► Serum cadherin-5 discriminated patients with recurrent breast cancerfrom those with no sign of recurrence with 90% specificity.