Differential distribution of soluble and complexed forms of prostate-specific antigen in cyst fluids of women with gross cystic breast disease

Gross cystic breast disease (GCBD) is the most common benign disease of the human female breast, and patients with GCBD have an increased risk of brea st cancer. The aim of this study was to evaluate the distribution inside ap ocrine cells and in breast cyst fluids aspirated from gross cysts of prosta te-specific antigen (PSA) molecular forms, and to correlate the different i ntracystic PSA profiles to the subpopulations of gross cysts. Type 1 cysts showed a median value of 0.71 mug/L of total PSA and 0.32 g/L of ACT, signi ficantly different to that of Type II cysts (Wilcoxon P < D. DO 1). Althoug h large excesses of ACT were detected in all samples, BCF samples and apocr ine cells from Type I gross cysts contained about 70% of free PSA, compared to the higher amounts of complexed PSA found in Type II gross cysts. We de monstrate that in apocrine/secretive Type I breast gross cysts the serine p rotease PSA was mainly present in its free form, in contrast to a major pro portion of complexed PSA found in flattened/transudative Type II cysts. Our results are consistent with the notion that a prolonged exposure of apocri ne breast cells lining the Type I gross cysts to the proteolytic activity o f PSA could be involved in the etiopathogenesis of GCBD. <(c)> 2001 Wiley-L iss, Inc.