Upregulation of Sulfated N-Glycans in Serum as Predictive Biomarkers for Early-Stage Breast Cancer.

Breast cancer (BC) is a major global health concern, and early detection is key to improving patient outcomes. Aberrant glycosylation, particularly the sulfation of glycans, is implicated in cancer progression; however, analyzing these low-abundance glycans is challenging. This study aimed to profile serum sulfated N-glycans in Ethiopian patients with BC to identify novel biomarkers for the early detection of BC. Using a glycoblotting-based sulphoglycomics workflow, including high-throughput glycoblotting enrichment, weak anion exchange (WAX) separation, and MALDI-TOF MS, serum samples from 76 BC patients and 20 healthy controls were analyzed. Statistical evaluation revealed significant differences in the sulfated N-glycan profiles. Seven mono-sulfated N-glycans were markedly elevated in patients with BC, demonstrating high diagnostic accuracy (AUC ≥ 0.8) in this internal cohort. Terminal Lewis-type glycan epitopes were prominent in sulfated glycans but were absent in their non-sulfated counterparts. The increased fucosylation and sialylation of sulfated glycans are statistically significant markers of early-stage BC. The preservation of sialic acid groups during the analysis ensured detailed structural insight. This pioneering study quantitatively examined sulfated N-glycans in BC and identified potential glyco-biomarkers for early detection. Validation in larger, diverse cohorts is needed to establish their broader diagnostic relevance and improve our understanding of cancer-associated glycomic alterations.