High-Mannose N-Glycans To Monitor Early Response to Chemotherapy in African Epithelial Ovarian Cancer Patients─A Pilot Study.

Epithelial ovarian cancer (EOC) remains the most lethal form of cancer despite improvements in surgical techniques and therapeutic interventions over recent decades. The high mortality rate is largely associated with a lack of sensitive and specific early diagnostic biomarkers to allow timely intervention. Hence, the identification and validation of novel noninvasive biomarkers for primary diagnosis and for disease monitoring is of high importance. Malignant transformations of N-glycosylation have been reported across various cancer types including EOC, but little is known about the N-glycome of African populations. In this work, we investigated aberrant N-glycosylation for the first time in an African EOC cohort comprising primary patients and those undergoing chemotherapy. In this pilot study, the N-glycome of African EOC and controls was comparable to those previously found in European cohorts. Of importance, high-mannose N-glycans increased with response to treatment in early chemotherapy cycles, and complex-type sialylated fucosylated N-glycans decreased, especially in the late chemotherapy cycles. Interestingly, the glycan-based index that we previously developed to detect primary EOC was more sensitive and specific than the routine diagnostic biomarker to identify primary EOC and to monitor chemoresponse in the early phase of the treatment.