Nipple aspirate fluid color is associated with breast cancer

Background: Fluid can be non-invasively aspirated from the breast nipple (nipple aspirate fluid, NAF). NAF may have many colors, including clear, white, yellow, green, and red/brown. While bloody spontaneous nipple discharge has been linked with breast cancer, the association of NAF color with cancer is not established. Our hypothesis was that red/brown NAF color was associated with breast cancer. The purpose of this study was to assess (1) if red/brown NAF is associated with the presence and progression of breast cancer, (2) the influence of prior needle or surgical biopsy on NAF color, and (3) if an association between NAF color and breast cancer was found, to develop a cancer predictive model including NAF color and cytology, and clinical information. Methods: Specimens were obtained from 848 breasts between 1999 and 2004 after subjects enrolled in an IRB approved protocol to evaluate biologic markers of breast cancer. Cytologic evaluation was performed on Papanicolaou-stained cytospin preparations of NAF. Results: Red/brown NAF was associated with breast cancer when considering all samples (p < 0.001) and samples from women who did not undergo recent surgery (p = 0.005). Needle biopsy did not, but surgical biopsy did influence NAF color. For the 327 women with NAF collected from both breasts, there was a significant association between red/brown NAF color and the presence of breast cancer (p = 0.005). Red/brown NAF was more common in breasts with ductal carcinoma in situ than atypical hyperplasia (p = 0.008). The optimal model, included NAF color, cytology, and age, was 92% sensitive and 61% specific in predicting if a woman had breast cancer. Conclusions: NAF color was associated with the presence of breast cancer and the progression from precancer to cancer in a population of women who presented to a breast cancer evaluation clinic. NAF color contributed to a highly predictive breast cancer detection model. Additional studies are warranted to determine the usefulness of NAF color in the assessment of women who present for breast cancer evaluation.