A number of studies have focused on the association between oral contraceptive (OC), hormonal replacement therapy (HRT) and reproductive factors and meningioma risk, but the results were inconsistent. Thus, a meta-analysis was performed to obtain more precise estimates of risk. We conducted a literature search using PubMed and EMBASE databases to July2013, without any limitations. Random effects models were used to summarize results. Twelve case-control and six cohort studies were included in this meta-analysis. We found that an increased risk of meningioma was associated with HRT use(RR = 1.19, 95% CI = 1.01–1.40), postmenopausal women(RR = 1.32, 95% CI = 1.07–1.64) and parity(RR = 1.18, 95% CI = 1.00–1.40).No significant associations were observed for OC use (RR = 0.93, 95% CI = 0.83–1.03), age at menarche(RR = 1.06, 95% CI = 0.92–1.21), age at menopause(RR = 1.03, 95% CI = 0.81–1.30), or age at first birth(RR = 0.94, 95% CI = 0.80–1.10). In conclusion, the results of our study support the hypothesis that longer exposure to effect of female sex hormones may increase the risk of meningioma in women, yet additional studies are warranted to confirm our findings and identify the underlying biological mechanisms.

Background: Standard treatment for high-grade glioma (HGG) includes surgery followed by radiotherapy and/or chemotherapy. Insertion of carmustine wafers into the resection cavity as a treatment for malignant glioma is currently a controversial topic among neurosurgeons. Our meta-analysis focused on whether carmustine wafer treatment could significantly benefit the survival of patients with newly diagnosed glioblastoma multiforme (GBM). Method: We searched the PubMed and Web of Science databases without any restrictions on language using the keywords “Gliadel wafers”, “carmustine wafers”, “BCNU wafers”, or “interstitial chemotherapy” in newly diagnosed GBM for the period from January 1990 to March 2015. Randomized controlled trials (RCTs) and cohort studies/clinical trials that compared treatments designed with and without carmustine wafers and which reported overall survival or hazard ratio (HR) or survival curves were included in this study. Moreover, the statistical analysis was conducted by the STATA 12.0 software. Results: Six studies including two RCTs and four cohort studies, enrolling a total of 513 patients (223 with and 290 without carmustine wafers), matched the selection criteria. Carmustine wafers showed a strong advantage when pooling all the included studies (HR =0.63, 95% confidence interval (CI) =0.49–0.81; P=0.019). However, the two RCTs did not show a statistical increase in survival in the group with carmustine wafer compared to the group without it (HR =0.51, 95% CI =0.18–1.41; P=0.426), while the cohort studies demonstrated a significant survival increase (HR =0.59, 95% CI =0.44–0.79; P<0.0001). Conclusion: Carmustine-impregnated wafers play a significant role in improving survival when used for patients with newly diagnosed GBM. More studies should be designed for newly diagnosed GBM in the future.

Studies of the association between excess body weight and risk of meningioma have produced inconsistent results. Therefore, a meta-analysis of published studies was performed to better assess the association between meningioma and excess body weight. A literature search was conducted in the PubMed and EMBASE databases without any limitations. The reference lists of identified articles were also screened for additional studies. The summary relative risks (RRs) and 95% confidence intervals (CI) were calculated using fixed- or random-effects models. A total of 6 studies provided risk estimates for overweight or obesity. Overall, the combined RRs were 1.12 (95% CI = 0.98–1.28) for overweight and 1.45 (95% CI = 1.26–1.67) for obesity. After stratification by gender, no significant association was observed for obese men (RR = 1.30, 95% CI = 0.64–2.62), while significant association was detected for obese women (RR = 1.46, 95% CI = 1.26–1.69). No substantial differences emerged across strata of study design and geographic areas. The results of this meta-analysis suggest that obesity but not overweight is associated with an increased risk of meningioma. Due to the limited number of studies, further research is needed to confirm the association.

Previous investigations of glioma risk in women have focused on oral contraceptive (OC), hormone replacement therapy (HRT), and reproductive factors. However, the results of published studies were inconclusive and inconsistent. Thus, a meta-analysis based on published case-control studies was performed to assess the role of exogenous and endogenous hormones factors in glioma risk. The PubMed and EMBASE databases were searched without any restrictions on language or publication year. Reference lists from retrieved articles were also reviewed. We included case-control studies reporting relative risks (RRs) with corresponding 95% confidence intervals (CIs) (or data to calculate them) between oral contraceptive (OC) and hormone replacement therapy (HRT) use, reproductive factors and glioma. Random-effects models were used to calculate the summary risk estimates. Finally, 11 eligible studies with 4860 cases and 14,740 controls were identified. A lower risk of glioma was observed among women who were ever users of exogenous hormones (OC RR = 0.707, 95% CI = 0.604–0.828; HRT: RR = 0.683, 95% CI = 0.577–0.808) compared with never users. An increased glioma risk was associated with older age at menarche (RR = 1.401, 95% CI = 1.052–1.865). No association was observed for menopause status, parous status, age at menopause, or age at first birth and glioma risk. The results of our study support the hypothesis female sex hormones play a role in the development of glioma in women. Additional studies are warranted to validate the conclusion from this meta-analysis and clarity the underlying mechanisms.

The relationship between risk of glioma and alcohol consumption has been widely studied, but results have been conflicting. We therefore conducted a meta-analysis of observational studies to systematically assess the relationship between alcohol drinking and risk of glioma. Two electronic databases (PubMed and EMBASE) were searched from inception to 8 August 2013 to identify pertinent studies that linked alcohol drinking with glioma risk. We used a random-effects model to calculate the overall relative risk (RR) with corresponding 95% confidence intervals (CIs). Fifteen case-control and four cohort studies were identified for this analysis. The combined RR for total alcohol drinkers versus non-drinkers was 0.96 (95% CI: 0.89–1.04). In the subgroup analysis by geographic area, a significant association was observed in North American studies (RR = 0.78, 95% CI: 0.65–0.93), but not in European or Asian/Australian studies. In the subgroup analysis by study design, a borderline significant association emerged in population-based case-control studies (RR = 0.82, 95% CI: 0.68–0.99), but not in hospital-based case-control studies (RR = 1.00, 95% CI: 0.99–1.01) or cohort group (RR = 1.03, 95% CI: 0.88–1.20). Our results show no material association between alcohol consumption and risk of glioma existed. Further prospective evidences are needed to confirm this association.

Endothelial nitric oxide synthase (eNOS) is the catalyst of endothelial nitric oxide (NO) synthesis. Polymorphisms in the eNOS gene may influence the risk of intracranial aneurysm (IA), but the results of existing researches are still inconsistent. Thus, we performed the present meta-analysis to derive a more precise estimation between eNOS polymorphisms (T786C, G894T, 27-bp-variable number of tandem repeat [VNTR]) and IA risk. Case–control studies evaluating the association between the eNOS polymorphisms and IA risk were searched in PubMed, Ovid & Embase, Web of Science, and Chinese Wanfang datasets with the last search up to July 15, 2014. The pooled odds ratios (ORs) for the association between eNOS polymorphisms and IA and their corresponding 95% confidence intervals (CIs) were estimated using the random or fixed-effects model. Finally, 10 studies for T786C polymorphism (1819 cases and 1893 controls), 9 studies for G894T polymorphism (1393 cases and 1508 controls), and 7 studies for 27-bp-VNTR polymorphism (1281 cases and 1406 controls) were included in the meta-analyses. In the overall analysis, no evidence of association between eNOS polymorphisms and susceptibility of IA was found. When subgrouped by race descent, significantly increased risk was detected among Asians for T786C polymorphism (heterozygous comparison of codominant model: OR = 1.294, 95% CI = 1.025–1.634; dominant model: OR = 1.277, 95% CI = 1.019–1.600), but not in Caucasians or the other 2 polymorphisms. Our meta-analysis suggested that T786C polymorphism was associated with increased risk of IA among Asians, whereas G894T and 27-bp-VNTR polymorphisms might have no influence on the susceptibility of IA.