RELATIONSHIPS BETWEEN ESTROGEN-INDUCIBLE PROTEINS, ESTRADIOL AND ELECTROLYTE RATIO IN BREAST CYST FLUID

Women who have breast cysts with intracystic Na+/K+ < 3 may have a hig her risk of developing breast cancer than women who have breast cysts with intracystic Na+/K+ > 3. In this study wide-ranging intracystic co ncentrations of cathepsin D and pS2 (oestrogen inducible proteins/poly peptides) as well as oestradiol were found. The concentrations of cath epsin D and oestradiol were significantly higher in the low electrolyt e ratio cyst group than in the high electrolyte ratio cyst group. No s ignificant difference was found between pS2 concentrations in the two groups. The significantly higher intracystic concentrations of catheps in D, a mitogenic lysosomal endopeptidase and oestradiol in the low el ectrolyte ratio group may partly provide an explanation for the higher risk of breast cancer which has been observed in this group of women.