title: Association between brain tumors and menopausal status.
abstract: BACKGROUND
  Several lines of evidence have implicated female hormones in the etiology of human brain tumors, meningiomas in particular.
  
  
  OBJECTIVE
  To investigate the relationship between brain tumor development and the hormonal changes manifested during pregnancy and menopause, we analyzed data from female participants in a population-based case-control study of adult brain tumors. This study was conducted in 1987-1988 in the Rhein-Neckar-Odenwald area of the Federal Republic of Germany.
  
  
  METHODS
  The study population consisted of 127 women with meningiomas, gliomas, and acoustic neuromas (case patients) and 233 control women who were selected from the general population and frequency-matched by age to the case patients. Information on parity, menopausal status, and previous gynecologic surgeries was obtained through a standardized questionnaire. Case patients and control subjects were compared with the use of the unconditional maximum likelihood estimation of the parameters in a logistic regression model.
  
  
  RESULTS
  Our results were not statistically significant; nevertheless, they revealed some interesting trends. No association was found between parity and the development of any of the three histological subtypes of brain tumor (relative risk [RR] = 1.31; 95% confidence interval [CI] = 0.51-2.07). Menopausal women had a greatly reduced risk of developing meningiomas (RR = 0.58; 95% CI = 0.18-1.90), and this effect was most pronounced when menopause had been surgically induced by bilateral oophorectomy (RR = 0.12; 95% CI = 0.01-1.30). Menopausal women had a greater risk of developing gliomas or acoustic neuromas (RR = 1.77; 95% CI = 0.67-4.68), except when menopause was surgically induced, in which case the risk was reduced (RR = 0.33; 95% CI = 0.04-3.09). Oophorectomy after menopause did not appear to influence risk.
  
  
  CONCLUSIONS
  Since the onset of menopause is accompanied by cessation of estrogen production, our results support the notion that female hormones play a role in the development of brain tumors.
authors.affiliation: Department of Epidemiology and Biometry, German Cancer Research Center, Heidelberg.
authors.forename: B
authors.initials: B
authors.lastname: Schlehofer
authors.forename: M
authors.initials: M
authors.lastname: Blettner
authors.forename: J
authors.initials: J
authors.lastname: Wahrendorf
mesh_terms: D000328:Adult; D000368:Aged; D001932:Brain Neoplasms / Q000209:etiology*; D016022:Case-Control Studies; D005260:Female; D005910:Glioma / Q000209:etiology*; D006801:Humans; D008579:Meningioma / Q000209:etiology*; D008593:Menopause; D008875:Middle Aged; D009464:Neuroma, Acoustic / Q000209:etiology*; D010052:Ovariectomy; D010298:Parity; D012306:Risk