STEROID BIOCHEMISTRY AND CATEGORIZATION OF BREAST CYST FLUID - RELATION TO BREAST-CANCER RISK

Patients bearing macrocysts of the breast are at higher risk of later developing cancer. The fluid filling the cysts (breast cysts fluid, BC F) contains unusual amounts of steroid conjugates, first androgen and estrogen sulfates. Measuring BCF cations (K+, Na+) allows categorizati on of cysts into two major subsets (type I and type II) that are assoc iated with a different degree and/or turnover of apocrine metaplastic cells in the lining epithelium. Type I cysts (high K+/Na+ ratio) accum ulate huge amounts of dehydroepiandrosterone sulfate, estrone sulfate, androstane-3 alpha,17 beta-diol glucuronide, androsterone glucuronide and contain more testosterone and dihydrotestosterone than type IL Co nversely, type II cysts (low K+/Na+ ratio) contain more progesterone a nd pregnenolone. A cohort study was study was started in 1983 at the C ancer Prevention Center, Ravenna, Italy, with the aim of evaluating th e relationships between the biochemistry of BCF and the incidence of b reast cancer in women with gross cystic disease (GCD) of the breast. T he bimodal distribution of the cationic pattern has been confirmed fro m data obtained in 798 patients aspirated. The risk of cyst relapse wa s significantly higher among women with type I cysts or with multiple cysts at presentation. Twelve incident cases of breast cancer have bee n diagnosed among women whose BCF was categorized. Eleven out of 12 ca ses had type I or multiple cysts. The cumulative incidence of breast c ancer among patients bearing type I cysts was 2.5%. We conclude that w omen with GCD bearing type I cysts have an increased breast cancer ris k when compared with the counterpart bearing type II cysts or the gene ral population.