Mass Spectrometry-Based Proteomics Analysis of Breast Milk for Breast Cancer Biomarker Discovery: An Update

Innovations in approaches for early detection and individual risk assessment of different cancers, including breast cancer (BC), are needed to reduce cancer morbidity and associated mortality. The assessment of potential cancer biomarkers in accessible bodily fluids provides a novel approach to identify the risk and/or onset of cancer. Biomarkers are biomolecules, such as proteins, that are indicative of an abnormality or a disease. Human milk is a vastly underutilized biospecimen that offers the opportunity to investigate potential protein BC-biomarkers in young, reproductively active women. As a first step, we have examined the entire protein pattern in human milk samples from breastfeeding mothers with cancer, who were diagnosed either before or after milk donation, and from women without cancer, using a variety of biochemical fractionation (1D-PAGE and 2D-PAGE) and mass spectrometry (MS)-based proteomics (nanoliquid chromatography tandem MS or nanoLC-MS/MS and matrix-assisted laser desorption ionization MS or MALDI-MS) for biomarker discovery as applied to BC using breast milk samples.