Lifestyle factors and primary glioma and meningioma tumours in the Million Women Study cohort

Abstract

Previous studies have reported inconsistent results on the effect of anthropometric and lifestyle factors on the risk of developing glioma or meningioma tumours. A prospective cohort of 1.3 million middle-aged women was used to examine these relationships. During 7.7 million women-years of follow-up, a total of 1563 women were diagnosed with a primary incident central nervous system tumour: 646 tumours were classified as glioma and 390 as meningioma. Our results show that height is related to the incidence of all central nervous system tumours with a risk of about 20% per 10 cm increase in height (relative risk ¼ 1.19, 95% CI ¼ 1.10 -1.30 per 10 cm increase in height, Po0.001): the risks did not differ significantly between specified glioma and meningioma. Body mass index (BMI) was also related to central nervous system tumour incidence, with a risk of about 20% per 10 kg m À2 increase in BMI (relative risk ¼ 1.17, 95% CI ¼ 1.03 -1.34 per 10 kg m À2 increase in BMI, P ¼ 0.02). Smoking status, alcohol intake, socioeconomic level, parity, age at first birth, and oral contraceptive use were not associated with the risk of glioma or meningioma tumours. In conclusion, for women in the United Kingdom, the incidence of glioma or meningioma tumours increases with increasing height and increasing BMI. British Journal of Cancer (2008) Keywords: body mass index; glioma; height; meningioma; women Primary brain and central nervous system cancers are relatively rare and represent approximately 2% of all cancers diagnosed in the United Kingdom. However, due to a poor prognosis, they are responsible for 7% of the years of life lost from cancer before the age of 70 years (Cancer Research UK, 2007). Very little is known about the aetiology of central nervous system tumours, but environmental factors are thought to play a role (McKinney, 2004;Connelly and Malkin, 2007).The two most common types of central nervous system tumour are glioma and meningioma (Claus et al, 2005). Gliomas arise from glial cells, are found predominantly in the brain and to a lesser extent in the spinal cord or other parts of the central nervous system, and represent more than 70% of all brain tumours (Ohgaki and Kleihues, 2005). Gliomas are typically histologically malignant, can be either slow or fast growing, and are more frequently diagnosed in men than in women. Meningiomas arise from the arachnoidal cells of the leptomeninges (the pia mater and arachnoid mater of the meninges) (Sanson and Cornu, 2000), are also more frequently found in the brain than elsewhere in the central nervous system, and represent more than 20% of all brain tumours (Longstreth et al, 1993). Meningiomas are typically benign (490%) and slow growing. The risk of meningioma increases with age (Sanson and Cornu, 2000), and they are more frequently diagnosed in women (Sanson and Cornu, 2000;Perry et al, 2007).There are few well-established risk factors for glioma and meningioma tumours among adults; while exposure to ionizing radiation and rare inherited genetic conditions such as n...

Nonmydriatic ocular fundus photography among headache patients in an emergency department

“…Either mechanism may explain the increased frequency of optic nerve pallor we found among patients with a high BMI because obesity is associated with idiopathic intracranial hypertension (IIH) and with an increased risk of CNS tumors, particularly meningiomas that frequently affect the anterior visual pathways. 22,23 Optic disc edema, representing nearly a third of the abnormalities found, was observed more frequently than optic disc pallor. Among patients who present to the ED with headache, this is particularly relevant because optic disc edema frequently indicates increased intracranial pressure, especially when bilateral, as was seen in more than 90% of the cases.…”

Do Steroid Hormones Play a Role in the Etiology of Glioma?

“…Findings concerning other reproductive factors, including age at first birth, parity, and menopausal status, have not been consistent. Three studies (17,22,24) found that women who had ever used oral contraceptives were at decreased risk, but there were no clear trends with duration of use, and the remaining studies provided no evidence of an association (16,(18)(19)(20). Several studies (16,17,22) reported that ever users of menopausal hormone therapy had reduced risk of glioma, but there was no trend with duration of use, and other studies (18,19,23,24) showed no association of ever use of hormone therapy or duration of use with glioma risk.…”

“…A number of epidemiologic studies (10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24), most of which have used a case-control design (10-12, 14-17, 19, 21, 22), have examined menstrual and reproductive factors and the use of exogenous hormones in relation to risk of glioma in women (10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24). Overall, these studies have yielded weak and inconsistent results.…”

Distribution of allele frequencies and effect sizes and their interrelationships for common genetic susceptibility variants

“…For lipid level, we define risk alleles as variants that are positively associated with total cholesterol and LDL, the increased level of which is known to confer risk of heart disease, but negatively associated with HDL, the increased level for which is considered protective. For height, although such definitions are more ambiguous, we considered variants that are positively associated with height as a risk allele because increased mortality has been previously reported for taller subjects (16)(17)(18)(19).…”