A total of 75 women will be recruited for this study over roughly 13 months (ten months of year 1 and 3 months of year 2) by a clinician. She will confirm from the patient chart the previous diagnosis of proliferative breast disease, obtain the type of breast disease diagnosed, how long ago it was diagnosed to the nearest month, and any breast or health problems that could affect the lavage results. The study subjects will fill out questionnaires, be weighed and measured for height, donate a 10-ml blood sample and undergo a breast lavage procedure. During the lavage procedure, breast nipple fluid and the lavage fluid will be collected.