Reproductive Factors and Risk of Meningioma and Glioma

Abstract

Female sex hormones have previously been suggested as possible risk factors for brain tumors, but published studies have reported conflicting results. We conducted a population-based case-control study of glioma (n = 626) and meningioma (n = 906) cases and randomly selected controls stratified on age and geographic region (n = 1,774) in Denmark, Finland, Norway, Sweden, and the United Kingdom. Unconditional logistic regression was used to estimate odds ratios (OR) for glioma and meningioma in relation to reproductive factors. A decreased glioma risk was associated with ever-pregnancy compared with neverpregnancy [OR, 0.8; 95% confidence interval (95% CI), 0.6-1.0]. Meningioma risk among women ages <50 years was increased in relation to number of pregnancies leading to a live birth (OR, 1.8; 95% CI: 1.1-2.8 for giving birth to 3 children compared with nulliparous women; P trend among parous women = 0.01). This relation was not found for older women. Breastfeeding among parous women increased the glioma risk (OR, 2.2; 95% CI, 1.3-3.9 for breast-feeding 36 months or more compared with breast-feeding 3 months or less). Menopausal status and age at menopause were not associated with meningioma or glioma risk. Our findings imply that reproductive hormones may influence the occurrence of meningioma and glioma.

Abrupt Regression of a Meningioma after Discontinuation of Cyproterone Treatment: Fig 1.

“…Meningiomas may enlarge during hormonal influx, particularly during pregnancy and in the luteal phase of the menstrual cycle. 2 In line with this, spontaneous regression of meningiomas has been reported after pregnancy. 3 Because meningiomas often express progesterone receptors and, albeit to a lesser extent, estrogen receptors, 4,5 it has been postulated that these hormones may influence the increase in tumor size by increasing blood volume and extracellular and intracellular fluid as well as by increasing proliferation of the tumor tissue.…”

International variation in the incidence of adult primary malignant neoplasms of the brain and central nervous system

“…This phenomenon has been reported specifically for gliomas [3], although one report from New York State indicated that the protective effect of female sex against glioblastomas (the most common form of adult gliomas) decreased after menopause [28]. That our results with respect to male/female rate ratios did not significantly differ by World Area population suggests that this male/ female difference is biologically based and that an explanation should be sought in genetic differences between males and females, sex hormones, and/or female reproductive factors [28,30]. Our results suggest that within an overall context of elevated male risk, female pre-menopausal sex hormones confer increased risk to females.…”

“…Our results suggest that within an overall context of elevated male risk, female pre-menopausal sex hormones confer increased risk to females. While reproductive and hormonal factors have been studied in relation to brain cancer risk, results have been conflicting and a coherent understanding has not emerged [30].…”

Successful treatment of multiple intracranial meningiomas with the antiprogesterone receptor agent mifepristone (RU486)

“…There are several lines of evidence suggesting that progesterone may impact meningioma growth. The use of hormone replacement therapy (HRT) [3,12,26] and oral contraceptives [12,14] have been associated with an increased risk of meningioma. Several case reports have suggested a growth-promoting role of progesterone-agonist treatment on meningiomas [2,5,6,22,25].…”