Estrogen receptors in prolactinomas: a clinico-pathological study.
BACKGROUND
Antiestrogens are effective in the treatment of estrogen receptor (ER) positive breast carcinoma. The use of antiestrogen therapy in pituitary adenomas, however, has not been explored. This study attempted to identify a population who may benefit from antiestrogen therapy.


METHODS
Prolactinomas from 29 patients (10 men, 19 women) were analyzed for ER and Ki-67 labeling index using immunohistochemistry. Nine of the 19 women were either amenorrheic or had not received exogenous estrogen for at least one year. Ten women were menstruating either spontaneously or as a result of estrogen administration. Factors including age, serum prolactin level, tumor size, evidence of tumor invasiveness and recurrence of tumor were evaluated to determine if they were predictive of ER expression.


RESULTS
Tumors from 6/10 (60%) men were positive for ER. Among women who were having menses, 9/10 (90%) tumors were positive, whereas 6/9 (67%) tumors from amenorrheic women were positive. Statistical analysis revealed that none of the variables: gender, age, menstrual status, Ki-67 proliferative rate, exposure to dopamine agonists, preoperative prolactin level, tumor size, or invasiveness was predictive for the presence of the receptor. The incidence of ER, however, was significantly reduced in recurrent tumors (p = 0.03).


CONCLUSIONS
ER expression is less likely in recurrent tumors. The efficacy of ER antagonists cannot be inferred by gender or estrogen exposure.
Kaptain
G J
GJ
Department of Neurosurgery, University of Virginia Health Sciences Center, Charlottesville 22908, USA. gjk5c@virginia.edu
Simmons
N E
NE
Alden
T D
TD
Lopes
M B
MB
Vance
M L
ML
Laws
E R
ER
D000328:Adult; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use; D020847:Estrogen Receptor Modulators / Q000627:therapeutic use; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000378:metabolism; D008297:Male; D010911:Pituitary Neoplasms / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology*; D015175:Prolactinoma / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology*; D011960:Receptors, Estrogen / Q000378:metabolism*; D013629:Tamoxifen / Q000627:therapeutic use
D018931:Antineoplastic Agents, Hormonal; D020847:Estrogen Receptor Modulators; D019394:Ki-67 Antigen; D011960:Receptors, Estrogen; D013629:Tamoxifen