Obesity is associated with atypia in breast ductal lavage of women with proliferative breast disease

Background: Benign proliferative breast disease without atypia slightly increases breast cancer risk but there are currently few clinical options for breast cancer prevention in this group of women. Methods: We conducted a pilot study of women with a past diagnosis of proliferative breast disease with a goal to determine if the characteristics of cells obtained by breast ductal lavage were related to nutritional factors. Results: There were 57 women who enrolled. A total of 39 women yielded nipple aspirate fluid (NAF) samples and 36 underwent breast ductal lavage. Five of the lavage samples were acellular and 28 had at least 200 cells. Surprisingly, atypia was present in 11 women. Presence of atypia was associated with slight changes in morphometric features of the epithelial cells such as measures of circularity as obtained by image analysis, but the only variable significantly different in women with atypia (versus no atypia) was a higher mean body mass index. Body mass index was also significantly correlated with C-reactive protein (CRP) levels in the nipple aspirate fluid, indicating that obesity might have a pro-inflammatory effect on the breast that can contribute to increased rates of atypia. Conclusions: Although the clinical significance of atypia in breast ductal lavage is uncertain, these results support further work on prevention of obesity as a strategy for reducing breast cancer risk.