Nipple aspiration is a noninvasive technique for obtaining breast fluids from the duct openings of the nipple for the evaluation of abnormalities associated with breast cancer. NAF contains cells and many proteins (e.g., PSA). Therefore, the fluid can be tested for malignant cells and for diagnostic biomarkers of breast cancer. NAF production can be realized in more than 80% of the women at high-risk for breast cancer. The average total protein concentration in NAF is 71 mg/mL. NAF proteome analysis holds promise as a noninvasive method to identify biomarkers for breast cancer diagnosis and prognosis.
