Concentration of aluminium in breast cyst fluids collected from women affected by gross cystic breast disease

Gross cystic breast disease (GCBD) is the most common benign breast disorder, but the molecular basis of cyst formation remains to be identified. If the use of aluminium-based antiperspirant salts is involved in the etiology of gross breast cyst formation, it might be expected that aluminium would be at elevated levels in human breast cyst fluid (BCF). Aluminium was measured by ICP-MS in 48 samples of BCF, 30 samples of human blood serum and 45 samples of human breast milk at different stages of lactation (colostrum, intermediate, mature). The median level of aluminium in apocrine type I BCF (n = 27, 150 µg l⁻¹) was significantly higher than in transudative type II BCF (n = 21, 32 µg l⁻¹; P <0.0001). By comparison, aluminium measurements gave a median concentration of 6 µg l⁻¹ in human serum and 25 µg l⁻¹ in human breast milk, with no difference between colostrum, intermediate and mature milk. Levels of aluminium were significantly higher in both types of BCF than in human serum (P <0.0001). However when compared with human breast milk, aluminium levels were only significantly higher in apocrine type I BCF (P <0.0001) and not in transudative type II BCF (P = 0.152). It remains to be identified why such high levels of aluminium were found in the apocrine type I BCF and from where the aluminium originated. However, if aluminium-based antiperspirants are found to be the source and to play any causal role in development of breast cysts, then it might become possible to prevent this common breast disorder. Copyright © 2008 John Wiley & Sons, Ltd.