Hormone therapy and brain tumors.

The incidence of meningiomas is two to three times higher in women than in men, yet it is a rare event (around one case per 10 000 woman-years). Preclinical and clinical studies point at potential effects of female sex hormones on brain tumors. Results from several prospective, large-scale studies indicate that postmenopausal hormone therapy may increase the risk for diagnosing meningioma by 30-80%, but there is no effect in regard to glioma. However, because of the very low incidence of meningioma in the general population of women, the absolute excess risk attributed to hormone therapy has no clinical impact.