SPINAL MENINGIOMAS IN WOMEN IN LOS-ANGELES-COUNTY - INVESTIGATION OF AN ETIOLOGIC HYPOTHESIS

A series of 3 studies explored the hypothesis that the preponderance o f spinal meningiomas among postmenopausal women relates to their highe r prevalence of spinal osteoporosis: (a) medical records showed that m eningiomas in women, unlike other spinal tumors, usually arise in the mid thoracic spine where osteoporotic vertebral fractures predominate; (b) radiographic evidence of osteoporosis was seen commonly with meni ngiomas but not with other spinal tumors; and (c) age-adjusted multiva riate analysis of data from an interview study of 81 women with spinal meningioma and 155 random digit dial controls showed 6 factors relate d to risk, Four factors were protective: (a) current use (at diagnosis ) of estrogen replacement therapy [odds ratio (OR) = 0.2; 95% confiden ce interval (CI) = 0.1-0.6]; (b) past use of oral contraceptives (P tr end <0.01); (c) past participation in sports (OR = 0.5; CI = 0.2-0.9); and (d) premenopausal status (OR = 0.2; CI = 0.1-0.7), Risk increased among women who had ever smoked cigarettes (OR = 1.7; CI = 0.9-3.1) o r had a history of high dose radiography (>500 mrad exposure to active marrow/examination; includes upper or lower gastrointestinal series a nd/or cardiac angiography; OR = 2.9, and CI = 1.6-5.3), although no as sociation was seen with prior radiotherapy, Other results that did not support the hypothesis include findings that cases and controls were similar in mean body weight and in the proportion who had postmenopaus al fractures or height loss, In conclusion, these studies lend some su pport to our hypothesis, but other known meningioma risk factors such as ionizing radiation also appear important, We propose that osteoporo tic collapse fractures of the vertebrae can traumatize the spinal meni nges, causing damage and subsequent repair of the meninges, and that t he cell proliferation that occurs during the repair process increases the likelihood of tumor development.