Determination of Salivary Sialic Acid Through Nanotechnology: A Useful Biomarker for the Screening of Breast Cancer

Purpose. To demonstrate the usefulness of sialic acid (SA) in saliva as a biomarker for breast cancer (BC) and develop a new tool for early detection. Methods. Considering that the amount of SA in human saliva is limited, the levels of SA were measured using surface-enhanced Raman spectroscopy (SERS) with tailored citrate-reduced silver nanoparticles. We calibrated the spectrum using analytical reagent SA. The 164 patients included in this study were undergoing screening mammography and/or ultrasound testing. The SA test was performed in the absence of previous information regarding the health of the subjects. Biopsies were performed to determine the diagnosis of cancer condition. The biopsy studies determined that 35 patients are BC affected and 129 gave negative results. Results. SERS showed a sensitivity and specificity of 80 and 93%, respectively. The cut-off value for SA (12.5 mg/dL) was established through a receiver operating characteristic (ROC) curve analysis. The area under the curve of the ROC analysis resulted in 95% with this SA level cut-off. Our results suggest that SA may be a useful biomarker for the screening of breast cancer in women. Conclusions. Our results suggest that the SA levels measured from saliva may be highly sensitive and specific markers for the presence of breast cancer. (C) 2019 IMSS. Published by Elsevier Inc.