Background: Nipple ductal lavage (NDL) is a new minimally invasive procedure with the potential to help identify women who could benefit from breast cancer risk intervention. NDL is currently encouraged for women with fluid-producing ducts and a 5-year Gail risk > or =1.7%. The purpose of this study was to evaluate the atypia rate by NDL in fluid-producing ducts compared with non-fluid-producing ducts and the atypia rate in high-risk verses low-risk patients to determine if current recommendations are supported.
Methods: Fifty-nine women were studied with NDL. The 226 ducts lavaged included all fluid-producing ducts (n = 136) and any dry ducts we could cannulate (n = 90). Breast cancer risk was calculated using mathematic models.
Results: There were 26 (44%) women with a 5-year Gail risk > or =1.7% and 33 (56%) with a 5-year Gail risk <1.7%. Cytologic atypia was diagnosed in 20 of 59 (34%) of patients. The atypia rate was similar for women with a 5-year Gail risk > or =1.7% (9 of 26 or 35%) compared with lower-risk women (11 of 33 or 33%, P = 1.0) and for fluid-producing ducts (26 of 136 or 19%) compared with dry ducts (14 of 90 or 15%, P = 0.61). No significant differences were found when the atypia was categorized as mild versus marked. Of note, the insufficient sample rate was higher for dry ducts (33%) compared with fluid-producing duct (22%, P = 0.07).
Conclusions: If NDL results are found to correlate with breast cancer incidence, it will be important to apply the test in a way that maximizes sensitivity for the detection of atypia in a screened population. We were unable to identify patient or duct characteristics that predict NDL atypia rates.