Immunoreactive hormones in human breast tissues

Samples of breast tissue obtained at biopsy or mastectomy from women with benign breast disease and infiltrating duct or anaplastic carcinoma were maintained for 2 weeks in organ culture synthetic medium 199 without additional serum or hormones. Media were changed every 48 hours. Media withdrawn from the tissues were assayed for insulin, prolactin (Prl), and parathyroid hormone (PTH). In addition, tissue explants were extracted in acid-alcohol and assayed for insulin by standard radioimmunoassay (RIA) procedures. At day 0 portions of breast tissue from patients with malignant or benign disease were fixed in Bouin solution; they were then embedded in paraffin; and serial sections were obtained for histologic and immunocytochemical examination. The dissection media assayed for insulin and PTH by RIA showed that the hormones were present in media from patients with benign as well as malignant disease. However, there was no significant difference between the two groups of women. Only traces of Prl were detected in media. The amount of insulin present in certain tissue explants appeared to increase with time in culture. Immunocytochemical studies showed that insulin-like or PTH-like immunostaining appeared most often in malignant tumor tissue and was observed infrequently or not at all in patients with benign disease. Prl-positive cells were rare. These data suggest that breast tissues contain and may synthesize significant amounts of certain hormones that may influence the growth and proliferation of breast cells.