Breast Anatomy and Nipple Aspirate Fluid (NAF) Collection

The female breast has two main components; glandular tissue (lobes and ducts) and connective tissue. The breast is divided into 5 to 7 lobes that radiate outwards from the nipple and contain clusters of milk-producing glands. The lobes are further divided into smaller compartments called lobules. Each cluster drains into a duct, which connects the lobules and the nipple. The breast is held together by fatty connective tissue, which provides support and contains nerves as well as blood and lymphatic vessels.

Adenocarcinoma is a general term that refers to a cancer that starts in glandular tissues anywhere in the body. Over 85% of breast cancers start in glandular tissue and therefore are classified as adenocarcinomas. Those that originate in lobules are known as lobular carcinoma and those that begin in ducts are ductal carcinomas. The term “noninvasive breast cancer” refers to adenocarcinomas that are confined to lobules or ducts. Another term used to describe these cancers is in situ. Invasive breast cancer refers to a carcinoma that has spread from lobules or ducts to fatty connective tissue.

It has been known since early studies in the 1950s by Dr. George Papanicolaou, the inventor of the “Pap smear” for cervical cancer, that adult non-pregnant, non-lactating women secrete fluid into the milk ducts of the breast. This fluid does not normally escape because the nipple orifices are occluded by smooth muscle contraction, dried secretions, and keratinized epithelium. This fluid contains several cell types, including exfoliated breast epithelial cells, both normal as well as atypical cells and even malignant cells. The fluid also contains molecular diagnostic biomarkers, including associated proteins, complex lipids, RNA, and DNA.

A number of medical devices have been designed over the ensuing decades that apply negative pressure to the nipple, like a suckling child, to induce the expression of Nipple Aspirate Fluid (NAF) which is then collected by carefully touching a capillary tube to any apparent drops of NAF. In general these devices are successful in obtaining NAF in from 39 to 66% of patients and the Company believes it is this sample collection variability that has prevented routine adoption of NAF cytology for screening.

The MASCT System was designed to overcome this shortcoming by placing a hydrophilic (“water seeking”) membrane in contact with the nipple during the cycles of negative pressure to “wick” fluid from the orifice of the ducts by capillary action, thereby increasing the frequency of obtaining NAF in women. During the clinical testing, the MASCT System collected fluid in 97% of women. We believe we are the only NAF collection system with this membrane design. The MASCT has been awarded 14 US and international patents for aspects of this design.