Increased hypothalamic dopaminergic tone only in early parous women with either malignant or benign breast tumors.
OBJECTIVE
To investigate whether the serum prolactin (PRL) response to a dopamine antagonist was different in nonobese, euthyroid women with malignant or benign breast tumors in comparison with healthy women, considering their age at first full-term pregnancy or their nulliparity.


METHODS
Serum PRL concentrations before and 60, 90, and 120 minutes after oral administration of metoclopramide (10 mg) were studied in 122 nonobese, nonsmoking, euthyroid women: 28 who had invasive breast cancer, stage I or II (group 1), 34 who had benign breast disease (group 2), and 60 who were clinically healthy (group 3). These three main groups were subdivided into early and late parous women (< or = 25 and >25 years, respectively) and nulliparous women, and the menopausal status was also considered.


RESULTS
Early parous women with invasive breast cancer (both premenopausal and postmenopausal) and early parous premenopausal women with benign breast disease had significantly higher serum PRL concentrations in response to administration of metoclopramide (P<0.05) and a greater area under the PRL curve (P<0.05) than those observed in early parous healthy women. No other significant differences in the serum PRL response were noted between or within groups.


CONCLUSIONS
The results of this study suggest the existence of an increased hypothalamic dopaminergic tone in early parous women but not in late parous or nulliparous women with malignant or benign breast tumors in comparison with similar healthy women. This finding may represent an adaptive protective mechanism attempting to prevent persistently increased serum PRL concentrations, a factor that could adversely affect the clinical evolution of the disease.
Ortega-González
Carlos
C
Instituto Nacional de Perinatología, Hospital General, Secretaria de Salud, Mexico City, Mexico. ortegacarlos@hotmail.com
Parra
Adalberto
A
Barra
Rosalba
R
Aranda
Carlos
C
Ramírez
Dana
D
Di Castro
Paolo
P
Castro
Ivone
I
Zambrana
Marcela
M
Coria
Irma
I
D000328:Adult; D000367:Age Factors; D001941:Breast Diseases / Q000503:physiopathology*; D001943:Breast Neoplasms / Q000503:physiopathology*; D004298:Dopamine / Q000502:physiology*; D018492:Dopamine Antagonists; D004958:Estradiol / Q000097:blood; D005260:Female; D006801:Humans; D007031:Hypothalamus / Q000503:physiopathology*; D007700:Kinetics; D008572:Menarche; D008787:Metoclopramide; D008875:Middle Aged; D010298:Parity; D011247:Pregnancy; D011374:Progesterone / Q000097:blood; D011388:Prolactin / Q000097:blood
D018492:Dopamine Antagonists; D011374:Progesterone; D004958:Estradiol; D011388:Prolactin; D008787:Metoclopramide; D004298:Dopamine