title: Hormonal treatment with sex steroids in women is associated with lower p105 serum concentrations.
abstract: BACKGROUND
  In breast and ovarian cancer patients elevated serum levels of the oncoprotein p105 were detected. We examined the influence of endocrine factors on the p105 serum concentration.
  
  
  METHODS
  The sera of 115 and non-pregnant women were analysed. Of the premenopausal women (n = 77) hormonal contraception was used by 30 women, and of the postmenopausal women (n = 33) there were 15 women using hormonal replacement therapy (HRT). The serum specimens were analysed by ELISA.
  
  
  RESULTS
  Women with hormonal contraception had significantly lower serum levels than premenospausal controls (82-138 fmol/ml, median 109 fmol/ml vs. 103-183 fmol/ml, median 130 fmol/ml; P < 0.001). In postmenopausal women with HRT serum levels were significantly lower than in postmenopausal controls (88-136 fmol/ml, median 117 fmol/ml vs. 99-261 fmol/ml, median 148 fmol/ml; P < 0.001).
  
  
  CONCLUSIONS
  Sex steroids seem to modulate c-erbB-2 activity. These results are important with regard to clinical studies on p105 oncoprotein in cancer patients.
authors.affiliation: Department of Obstetrics and Gynecology, University of Göttingen, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Meden
authors.forename: S
authors.initials: S
authors.lastname: Mielke
authors.forename: D
authors.initials: D
authors.lastname: Marx
authors.forename: W
authors.initials: W
authors.lastname: Wuttke
authors.forename: W
authors.initials: W
authors.lastname: Kuhn
mesh_terms: D003278:Contraceptives, Oral, Hormonal / Q000494:pharmacology*; D015914:Estrogen Replacement Therapy; D005260:Female; D012739:Gonadal Steroid Hormones / Q000494:pharmacology*; D006801:Humans; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000097:blood*
chemical_list: D003278:Contraceptives, Oral, Hormonal; D012739:Gonadal Steroid Hormones; D018719:Erb-b2 Receptor Tyrosine Kinases