Estrogen Receptors in Human Pituitary Tumors

Abstract

and hyperprolactinemia. In these rats the administration of the dopaminergic agonist bromocriptine reduces the levels of serum prolactin and the size of the pituitary gland [5, 6]. Estrogens also stimulate cell proliferation in breast tissue and the presence of estrogen receptors in breast cancer is an important sign in the degree of differentiation and an important indication of prognosis and treatment selection [7, 8]. Thus, the presence of estrogen receptors in breast cancer indicates a more differentiated tissue and a better prognosis than the absence of this protein. Furthermore the concentration of estrogen receptors in breast cancer cells contributes to the stadifi cation of breast cancer and allows making a rational decision on the usefulness of the treatment with anti-estrogen [9]. Although pituitary tumors are almost entirely histologically benign, their behavior varies considerably after surgery and / or in their response to dopaminergic agonists. Some of them are fast growing adenomas and relapse rapidly after surgery requiring treatment with dopaminergic agonists almost immediately. Others are apparently cured by surgery: prolactinemia remains within normal range and there are no signs of regrowth. There are all kinds of intermediate cases between these two above mentioned options. We have shown that dopaminergic ago-Authors

Hyperprolactinemia and prolactinoma

“…The high incidence of prolactinomas in women during their reproductive period, but not after menopause, is remarkable and unique for pituitary adenomas. This is probably related to the observation that estrogen receptors are expressed mainly in prolactin-producing pituitary adenomas, but rarely in other adenomas (Burdman et al, 2008).…”

Expression of estrogen receptor alpha is associated with prolactin pituitary tumor prognosis and supports the sex-related difference in tumor growth

“…In the Law's series (12) (14) noted that the two tumors negative for ERa were larger than the three positive ones and Kaptain et al (12) observed that recurrent tumors (previously treated surgically) were less likely to express ERa. In the present series, we applied for the first time to pituitary tumors, an IR score adapted from studies in breast cancer to evaluate ER expression.…”

“…Immunohistochemical (IHC) detection of ERa, used in breast cancer management, has progressively improved over the years with new generation ER-antibodies, the establishment of a semi-quantitative immunoreactive (IR) score (10), and the use of automated analysis (11). The IHC detection of ERa in pituitary PRL tumors has been studied by several authors, all of whom failed to demonstrate sex-related differences (8,12,13,14,15). However, these studies used manual immunostaining techniques, did not establish an IR score, and more recent ones (14,15) included only five and six tumors respectively.…”

“…The IHC detection of ERa in pituitary PRL tumors has been studied by several authors, all of whom failed to demonstrate sex-related differences (8,12,13,14,15). However, these studies used manual immunostaining techniques, did not establish an IR score, and more recent ones (14,15) included only five and six tumors respectively.…”

Prolactinoma in Children and Adolescents

“…This could be one possible paracrine factor in the development and aggressiveness of prolactinomas [16]. Paradoxically, Burdman et al [17] have recently shown that the most aggressive tumors were those negative for estrogen receptors within prolactinomas. In certain tumors, the regulatory mechanisms might not be operating properly and estrogen receptors might not be necessary for the regulation of PRL levels, and therefore absent.…”