Hormonal determinants of nipple aspirate fluid yield among breast cancer cases and screening controls.

Background: Nipple aspiration fluid (NAF) use as a biosample is limited by the variable yield across studies. We investigated the endocrine determinants of yield in an ongoing breast cancer case-control study.

Methods: One-hundred and eighteen women yielding ≥2 μL NAF and 120 non-yielders were included; serum hormones were measured; differences in median hormones were assessed using the Wilcoxon rank-sum test.