Gross
cystic breast disease is a common condition. Women with apocrine
breast cysts may be at higher risk of
breast cancer than women with
cysts which are lined by flattened epithelium. Apocrine
cysts have been shown to be associated with higher intracystic levels of
dehydroepiandrosterone sulphate and intracystic
sodium to
potassium ratios of less than 3. In this study we measured the concentrations of
epidermal growth factor,
dehydroepiandrosterone and its sulphate in
breast cyst fluid. The concentrations of all three analytes were significantly higher in
cysts with intracystic Na+/K+ ratios of less than 3 than in
cysts with
electrolyte ratios of greater than or equal to 3 (P less than 0.001). The higher levels of
EGF in
cysts with low intracystic
electrolyte ratios may provide an explanation of why women with apocrine
cysts may be at greater risk of
breast cancer. Positive correlations were obtained between concentrations of
EGF and
DHAS and between
EGF and DHA, compatible with the view that intracystic
EGF levels may be
androgen-modulated. A positive correlation was also obtained between DHA and
DHAS concentrations which supports the view that DHA in cyst fluid may be derived from the metabolism of
DHAS in the
breast cyst wall.