Accumulation of active androgens in breast cyst fluids.

80 breast cyst fluids (BCF) from 57 patients were divided by K+/Na+ ratio: 56 with ratio over 1 (type I) and 24 with ratio less than 1 (type II). Significantly higher amounts of testosterone, dihydrotestosterone and dehydroepiandrosterone sulphate (DHAS) were found in type I than in type II cysts. A positive relation was found between testosterone and dihydrotestosterone in both types. DHAS was significantly correlated with testosterone and dihydrotestosterone in type I casts only. In 52 patients, blood was sampled after cyst evacuation. Testosterone was significantly higher in blood than in BCF while dihydrotestosterone and androstenedione were significantly higher in BCF. No relation was observed between circulating levels of androgens and their intracystic concentrations. Women bearing type I cysts may be at increased risk of developing cancer. These findings support the hypothesis that androgens play a role in the hormonal aetiology of breast cancer.