Studies on clinical, hormonal and pathological correlations in breast fibroadenomas

Abstract

Plasma progesterone and estradiol were measured throughout the menstrual cycle in 84 patients with breast fibroadenoma. These in vivo data were compared to the levels of estradiol receptor protein (ER) ∗ as assayed in vitro on cytosol of tumor tissue obtained at surgery. Plasma progesterone (P) levels for all the patients (11.7 ± 2.8 ng/ml) were significantly lower ( P < 0.001) than those of normal women (21.0 ± 8.0 ng/ml) studied at the same days of the luteal phase. In addition, plasma estradiol (E 2) levels during the luteal phase were elevated: 289.6 ± 51.5 compared to 180.3 ± 82.0 pg/ml in normal women ( P < 0.01). The patients were divided in three groups according to the ER levels. The group with high ER concentration (H-ER > 20 fmol/mg protein, 11 cases) was also found to have the highest cell proliferation, whereas in the 49 patients with the lowest ER concentration (L-ER < 7 fmol/mg protein) there was an important stromal reaction. In 28 cases where ER binding site levels varied from 7 to 20 fmol/mg protein (M-ER), the cellular density was intermediate between both groups. The observation of positive estradiol receptor protein in fibroadenomas where the epithelial cellularity is most important emphasizes the role of estradiol in cellular multiplication and hyperplasia. In addition, the observation in vivo of an estradiol/progresterone imbalance in all the patients studied indicates that this could be the primary cause favouring the development of benign dystrophy in the mammary gland.