Influence of county-level geographic/ancestral origin on glioma incidence and outcomes in US Hispanics.

BACKGROUND: Glioma incidence is 25% lower in Hispanics than White non-Hispanics. The US Hispanic population is diverse, and registry-based analyses may mask incidence differences associated with geographic/ancestral origins. METHODS: County-level glioma incidence data in Hispanics were retrieved from the Central Brain Tumor Registry of the United States. American Community Survey data were used to determine the county-level proportion of the Hispanic population of Mexican/Central American and Caribbean origins. Age-adjusted incidence rate ratios and incidence rate ratios (IRRs) quantified the glioma incidence differences across groups. State-level estimates of admixture in Hispanics were obtained from published 23andMe data. RESULTS: Compared to predominantly Caribbean-origin counties, predominantly Mexican/Central American-origin counties had lower age-adjusted risks of glioma (IRR = 0.83; P < 0.0001), glioblastoma (IRR = 0.86; P < 0.0001), diffuse/anaplastic astrocytoma (IRR = 0.78; P < 0.0001), oligodendroglioma (IRR = 0.82; P < 0.0001), ependymoma (IRR = 0.88; P = 0.012), and pilocytic astrocytoma (IRR = 0.76; P < 0.0001). Associations were consistent in children and adults and using more granular geographic regions. Despite having lower glioma incidence, Hispanic glioblastoma patients from predominantly Mexican/Central American-origin counties had poorer survival than Hispanics living in predominantly Caribbean-origin counties. Incidence and survival differences could be partially explained by state-level estimates of European admixture in Hispanics with European admixture associated with higher incidence and improved survival. CONCLUSIONS: Glioma incidence and outcomes differ in association with the geographic origins of Hispanic communities, with counties of predominantly Mexican/Central American origin at significantly reduced risk and those of Caribbean origin at comparatively greater risk. Although typically classified as a single ethnic group, appreciating the cultural, socioeconomic, and genetic diversity of Hispanics can advance cancer disparities research.

MTHFR C677T and A1298C Polymorphisms in Breast Cancer, Gliomas and Gastric Cancer: A Review.

Folate (vitamin B9) is found in some water-soluble foods or as a synthetic form of folic acid and is involved in many essential biochemical processes. Dietary folate is converted into tetrahydrofolate, a vital methyl donor for most methylation reactions, including DNA methylation. 5,10-methylene tetrahydrofolate reductase (MTHFR) is a critical enzyme in the folate metabolism pathway that converts 5,10-methylenetetrahydrofolate into 5-methyltetrahydrofolate, which produces a methyl donor for the remethylation of homocysteine to methionine. MTHFR polymorphisms result in reduced enzyme activity and altered levels of DNA methylation and synthesis. MTHFR polymorphisms have been linked to increased risks of several pathologies, including cancer. Breast cancer, gliomas and gastric cancer are highly heterogeneous and aggressive diseases associated with high mortality rates. The impact of MTHFR polymorphisms on these tumors remains controversial in the literature. This review discusses the relationship between the MTHFR C677T and A1298C polymorphisms and the increased risk of breast cancer, gliomas, and gastric cancer. Additionally, we highlight the relevance of ethnic and dietary aspects of population-based studies and histological stratification of highly heterogeneous tumors. Finally, this review discusses these aspects as potential factors responsible for the controversial literature concerning MTHFR polymorphisms.

Two novel genetic variants in the STK38L and RAB27A genes are associated with glioma susceptibility.

Glioma is the most common malignant primary brain tumors with poor prognosis. Genome wide association studies (GWAS) of glioma in populations with Western European ancestry were completed in the US and UK. However, our previous results strongly suggest the genetic heterogeneity could be important in glioma risk. To systematically investigate glioma risk-associated variants in Chinese population, we performed a multistage GWAS of glioma in the Han Chinese population, with a total of 3,097 glioma cases and 4,362 controls. In addition to confirming two associations reported in other ancestry groups, this study identified one new risk-associated locus for glioma on chromosome 12p11.23 (rs10842893, pmeta = 2.33x10-12, STK38L) as well as a promising association at 15q15-21.1 (rs4774756, pmeta = 6.12x10-8, RAB27A) in 3,097 glioma cases and 4,362 controls. Our findings demonstrate two novel association between the glioma risk region marked by variant rs10842893 and rs4774756) and glioma risk. These findings may advance the understanding of genetic susceptibility to glioma.

Adult Glioma Incidence and Survival by Race or Ethnicity in the United States From 2000 to 2014.

Importance: Glioma is the most commonly occurring malignant brain tumor in the United States, and its incidence varies by age, sex, and race or ethnicity. Survival after brain tumor diagnosis has been shown to vary by these factors. Objective: To quantify the differences in incidence and survival rates of glioma in adults by race or ethnicity. Design, Setting, and Participants: This population-based study obtained incidence data from the Central Brain Tumor Registry of the United States and survival data from Surveillance, Epidemiology, and End Results registries, covering the period January 1, 2000, to December 31, 2014. Average annual age-adjusted incidence rates with 95% CIs were generated by glioma histologic groups, race, Hispanic ethnicity, sex, and age groups. One-year and 5-year relative survival rates were generated by glioma histologic groups, race, Hispanic ethnicity, and insurance status. The analysis included 244 808 patients with glioma diagnosed in adults aged 18 years or older. Data were collected from January 1, 2000, to December 31, 2014. Data analysis took place from December 11, 2017, to January 31, 2018. Results: Overall, 244 808 patients with glioma were analyzed. Of these, 150 631 (61.5%) were glioblastomas, 46 002 (18.8%) were non-glioblastoma astrocytomas, 26 068 (10.7%) were oligodendroglial tumors, 8816 (3.6%) were ependymomas, and 13 291 (5.4%) were other glioma diagnoses in adults. The data set included 137 733 males (56.3%) and 107 075 (43.7%) females. There were 204 580 non-Hispanic whites (83.6%), 17 321 Hispanic whites (7.08%), 14 566 blacks (6.0%), 1070 American Indians or Alaska Natives (0.4%), and 5947 Asians or Pacific Islanders (2.4%). Incidences of glioblastoma, non-glioblastoma astrocytoma, and oligodendroglial tumors were higher among non-Hispanic whites than among Hispanic whites (30% lower overall), blacks (52% lower overall), American Indians or Alaska Natives (58% lower overall), or Asians or Pacific Islanders (52% lower overall). Most tumors were more common in males than in females across all race or ethnicity groups, with the great difference in glioblastoma where the incidence was 60% higher overall in males. Most tumors (193 329 [79.9%]) occurred in those aged 45 years or older, with differences in incidence by race or ethnicity appearing in all age groups. Survival after diagnosis of glioma of different subtypes was generally comparable among Hispanic whites, blacks, and Asians or Pacific Islanders but was lower among non-Hispanic whites for many tumor types, including glioblastoma, irrespective of treatment type. Conclusions and Relevance: Incidence of glioma and 1-year and 5-year survival rates after diagnosis vary significantly by race or ethnicity, with non-Hispanic whites having higher incidence and lower survival rates compared with individuals of other racial or ethnic groups. These findings can inform future discovery of risk factors and reveal unaddressed health disparities.

Pleckstrin homology-like domain family B member 1 rs498872 polymorphism and glioma risk in Chinese Han population.

This case-control study aimed to investigate the association between PHLDB1 rs498872 polymorphism and the risk of glioma in a Chinese Han population. A total of 210 patients and 235 controls were enrolled in this study. The CT genotype and TT genotype were significantly associated with the risk of glioma (OR=1.48, 95%CI 1.00-2.19, P=0.05 and OR=2.40, 95%CI 1.06-4.10, P=0.03), respectively. In addition, T allele of PHLDB1 rs498872 polymorphism was significantly associated with an increased risk of glioma (OR=1.58, 95%CI 1.08-2.29, P=0.02). We also found that PHLDB1 rs498872 polymorphism was not associated with histology and tumor grade of glioma. In conclusion, this study found that PHLDB1 rs498872 polymorphism was significantly associated with glioma risk in Chinese Han population.

Association between common polymorphisms in ERCC gene and glioma risk: A meta-analysis of 15 studies.

BACKGROUND: A number of studies have investigated the roles of excision repair cross complementation group 1 (ERCC1), ERCC2, and ERCC5 genes polymorphisms in the development of glioma; however, the results were inconsistent. Here, we performed a meta-analysis to investigate the association between 6 polymorphisms in the ERCC genes (rs3212986, rs11615, rs13181, rs1799793, rs238406, rs17655) and glioma risk. METHODS: The PubMed, Embase, and Web of science were searched up to September 6, 2016, for studies on the association between ERCC polymorphisms and glioma risk. A fixed-effects or random-effects model was used to calculate the pooled odds ratios based on the results from the heterogeneity tests. Sensitivity and cumulative meta-analyses were also performed. RESULTS: A total of 15 studies were eligible for the pooled analysis, conducted in 2 populations of ethnic descent: 8 Europeans and 7 Asians. The results showed that ERCC1 rs3212986 polymorphism was positively associated with glioma [AA vs CC: odds ratio (OR) = 1.298, 95% confidence interval (95% CI) = 1.043-1.230, P = .025]. Association of the ERCC2 rs13181 and rs1799793 polymorphisms was only observed in Asians (CC vs AA for rs13181: OR = 1.539, 95% CI = 1.122-2.109, P = .007; AA vs GG for rs1799793: OR = 1.474, 95% CI = 1.090-1.994, P = .012). However, no association was observed between glioma risk and ERCC1 rs11615, ERCC2 rs238406, and ERCC5 rs17655 polymorphisms. Moreover, sensitivity and cumulative meta-analyses confirmed the stability of the results. CONCLUSIONS: Our meta-analysis indicated that the ERCC1 rs3212986 polymorphism and 2 polymorphisms in ERCC2 gene (rs13181 and rs1799793) contributed to the susceptibility of glioma.

Impact of interaction between the G870A and EFEMP1 gene polymorphism on glioma risk in Chinese Han population.

AIMS: To investigate the impact of CCND1 and EFEMP1 gene polymorphism, and additional their gene-gene interactions and haplotype within EFEMP1 gene on glioma risk based on Chinese population. METHODS: Logistic regression was performed to investigate association between single-nucleotide polymorphisms (SNP) and glioma risk and generalized multifactor dimensionality reduction (GMDR) was used to analyze the gene-gene interaction. RESULTS: Glioma risks were higher in carriers of homozygous mutant of rs603965 within CCND1 gene, rs1346787 and rs3791679 in EFEMP1 gene than those with wild-type homozygotes, OR (95%CI) were 1.67 (1.23-2.02), 1.59 (1.25-2.01) and 1.42 (1.15-1.82), respectively. GMDR analysis indicated a significant two-locus model (p=0.0010) involving rs603965 within CCND1 gene and rs1346787 within EFEMP1 gene. Overall, the cross-validation consistency of the two- locus models was 10\ 10, and the testing accuracy is 60.17%. Participants with rs603965 - GA or AA and rs1346787- AG or GG genotype have the highest glioma risk, compared to participants with rs603965 - GG and rs1346787- AA genotype, OR (95%CI) was 3.65 (1.81-5.22). We conducted haplotype analysis for rs1346787 and rs3791679, because D' value between rs1346787 and rs3791679 was more than 0.8. The most common haplotype was rs1346787 - A and rs3791679- G haplotype, the frequency of which was 0.4905 and 0.4428 in case and control group. CONCLUSIONS: Polymorphism in rs603965 within CCND1 gene and rs1346787 within EFEMP1 gene and its gene- gene interaction were associated with increased glioma risk.

Correlations of MGMT genetic polymorphisms with temozolomide resistance and prognosis of patients with malignant gliomas: a population-based study in China.

This study aims to investigate the associations of O6-methylguanine-DNA methyltransferase (MGMT) genetic polymorphisms (Leu84Phe and Ile143Val) with temozolomide (TMZ) resistance and prognosis of patients with malignant gliomas. A total of 212 patients diagnosed with malignant gliomas were enrolled in this study as the case group. All of these patients took oral TMZ and were assigned into the TMZ-sensitive (complete response+partial response) and the TMZ-resistant (stable disease+progressive disease) groups based on the clinical response after chemotherapy. The polymerase chain reaction-restriction fragment length polymorphism was used to identify the gene polymorphism of Leu84Phe and Ile143Val. The survival time and survival outcomes of all the patients were obtained by follow-up. There were significant differences in the genotype and allele of Leu84Phe between the TMZ-sensitive and the TMZ-resistant groups. The CT, TT and CT+TT genotypes and the T allele of MGMT gene Leu84Phe may be associated with increasing TMZ resistance in patients with malignant gliomas. Logistic regression analysis showed that Leu84Phe of MGMT gene and pathological grade were independent risk factors for the increase of TMZ resistance in patients with malignant gliomas. Kaplan-Meier survival curve revealed that the average survival time of patients with the CT+TT and CC genotypes of Leu84Phe in the two groups was statistically significant. COX regression analysis showed that Leu84Phe, degree of resection and pathological grade were independent prognostic factors for patients with malignant gliomas. Our study demonstrates that Leu84Phe of MGMT gene might be a risk factor of TMZ resistance and poor prognosis of patients with malignant gliomas.

Investigation of the role of XRCC1 genetic polymorphisms in the development of gliomas in a Chinese population.

We conducted a study in a Chinese Han population to investigate the role of XRCC1 gene polymorphisms (Arg399Gln and Arg194Trp) with a risk of susceptibility to gliomas. Samples from 115 patients with gliomas and 228 control subjects were consecutively collected between March 2012 and December 2014. Genotype analysis of XRCC1 Arg399Gln and Arg194Trp was performed using polymerase chain reaction-restriction fragment length polymorphism assay. All the analyses were performed using the SPSS 17.0 software package. We observed that the XRCC1 Arg399Gln and Arg194Trp genotype frequencies conformed to the Hardy-Weinberg equilibrium. We observed that the Trp/Trp genotype of XRCC1 Arg194Trp was associated with an increased risk of glioma when compared to the wild-type genotype (odds ratio (OR) = 2.14, 95% confidence interval (CI) = 1.14-3.86, P = 0.03). In the dominant model, we found that the Arg/Trp + Trp/Trp genotype of XRCC1 Arg194Trp could significantly elevate the susceptibility of developing glioma (OR = 1.79, 95%CI = 1.07-0.94). However, we observed that the XRCC1 Arg399Gln genetic polymorphism did not influence the risk of glioma. In summary, we suggest that the XRCC1 Arg194Trp genetic polymorphism could be a predictive biomarker for the susceptibility to glioma in a Chinese population.

Assessing the association between EFEMP1 rs3791679 polymorphism and risk of glioma in a Chinese Han population.

In this study, we assessed the association between the EFEMP1 rs3791679 polymorphism and glioma risk in a Chinese Han population. A total of 94 glioma patients and 206 healthy controls who conformed to the inclusion and exclusion criteria were recruited from Baogang Hospital between March 2012 and October 2014. The EFEMP1 rs3791679 gene polymorphism was assessed using a polymerase chain reaction-restriction fragment length polymorphism assay and the results were statistically analyzed using SPSS Statistics 17.0. The results of unconditional logistic regression analysis revealed that the GG genotype of EFEMP1 rs3791679 was positively correlated with increased susceptibility to glioma (adjusted OR = 2.09, 95%CI = 1.21-7.81). Moreover, the GG genotype of EFEMP1 rs3791679 was correlated with higher risk of glioma compared to the AA+GA genotype (OR = 2.60, 95%CI = 1.08-6.28) in the regressive model. In conclusion, we report that the EFEMP1 rs3791679 polymorphism influences glioma susceptibility in the Chinese Han population.

Effect of CDKN2A/B rs4977756 polymorphism on glioma risk: a meta-analysis of 16 studies including 24077 participants.

So far, epidemiological studies have been performed to investigate the association of CDKN2A/B rs4977756 polymorphism and glioma risk. However, the results from different studies remain inconsistent. To clarify these conflicts and to quantitatively evaluate the effect of rs4977756 polymorphism on glioma risk, a meta-analysis was conducted using relevant published clinical studies about rs4977756 polymorphisms and glioma risk. Relevant studies concerning the association between rs4977756 polymorphism and risk of glioma were included in this meta-analysis. Odds ratio (OR) and 95 % confidence interval (CI) were calculated under fixed or random effects models when appropriate. Subgroup analyses were performed by race. This meta-analysis included 13 studies with a total of 8129 cases and 15,858 controls. The pooled results showed that there was an obvious association of CDKN2A/B rs4977756 polymorphism with risk of glioma in all four comparison models (dominant model/AG + GG vs. AA: OR = 1.36, 95 %CI = 1.20-1.54, p < 0.01; heterozygote comparison/AG vs. AA: OR = 1.31, 95 %CI = 1.12-1.53, p < 0.01; homozygote comparison/GG versus AA: OR = 1.49, 95 %CI = 1.36-1.64, p < 0.01; additive model/G vs. A: OR = 1.23, 95 %CI = 1.18-1.28, p < 0.01, respectively). For the subgroup analyses of ethnicities, similar results were observed in Caucasians. However, the association was not found between rs4977756 polymorphism and the risk of glioma in all models for the Asian studies. The CDKN2A/B rs4977756 polymorphism is obvious increase the risk of glioma in Caucasians. Future studies are needed to confirm the results in other ethnic populations.

CCDC26 rs4295627 polymorphism (8q24.21) and glioma risk: a meta-analysis.

The association between the CCDC26 rs4295627 single nucleotide polymorphism (SNP) and the glioma risk has been studied previously, but these studies have yielded conflicting results. The aim of the present study is to analyze this association more vigorously, by means of a meta-analysis. A comprehensive literature search was performed in databases PubMed and EMBASE. Six articles including 12 case-control studies in English with 11,368 controls and 5891 cases were eligible for the meta-analysis. We conducted subgroup analyses by the source of controls, ethnicity, and country. Our meta-analysis revealed that the rs4295627 SNP was associated with the glioma risk in a heterozygote model (TG versus TT: odds ratio = 1.35, 95% confidence interval = 1.26-1.45, P = 0.066). Moreover, our results suggested that the rs4295627 SNP was associated with a notably increased risk of glioma among Caucasians except for Swedes in 4 models (the homozygote model, recessive model, dominant model, and additive model). Nonetheless, in Sweden and China, the results showed no associations. No evidence of the publication bias was uncovered. Thus, our meta-analysis suggests that the rs4295627 SNP is associated with an increased risk of glioma. Additional studies are needed to derive more precise conclusion.

DNA repair gene XRCC3 variants are associated with susceptibility to glioma in a Chinese population.

The susceptibility to glioma is not well understood. It has been suggested that the X-ray cross complementing group 3 (XRCC3) gene influences the capacity to repair DNA damage, leading to increased glioma susceptibility. In this study, we evaluated the relationship between XRCC3 mutations and glioma risk. Genotypes were assessed in 389 Chinese glioma patients and 358 healthy controls. XRCC3 Thr241Met (rs861539) and 2 additional polymorphisms, rs3212112 (c.774+19T>G) and rs1799796 (c.562-14A>G), were directly sequenced. The frequency of the rs861539 T allele was significantly lower in the glioma group than in healthy controls [11.1 vs 17.7%, odds ratio = 0.62 (0.48-0.80), P < 0.001]; the frequencies of the CT or CT+TT genotypes differed between groups (18.5 vs 31%, 20.3 vs 33.2%, respectively). The frequency of the rs3212112 G allele was significantly higher in the glioma group than in healthy controls [15.8 vs 5.3%, odds ratio = 2.94 (2.07-4.17), P < 0.001]. The frequencies of the GT or TG+GG genotypes differed between groups (25.4 vs 7.8%, 28.5 vs 9.2%, respectively). This study demonstrates that the rs861539 and rs3212112 polymorphisms in the XRCC3 gene may influence the risk of glioma development in Chinese populations.

International Differences in Treatment and Clinical Outcomes for High Grade Glioma.

BACKGROUND: High grade gliomas are the most common type of malignant brain tumor, and despite their rarity, cause significant morbidity and mortality. This study aimed to compare the treatment patterns of high grade glioma to examine survival patterns in patients who receive specific treatments between cohorts in Ohio and Taiwan. METHOD: Patients aged 18 years and older at age of diagnosis with World Health Organization (WHO) grade III or IV astrocytoma from 2007-2012 were selected from the Ohio Brain Tumor Study and the Taiwan Cancer Registry. The treatment information was derived from medical chart reviews in Ohio and National Health Insurance Research Data in Taiwan. Treatment examined included surgical procedure (brain biopsy and/or resection), radiotherapy (radiation and/or radiosurgery), and alkylating chemotherapy. Kaplan-Meier and parametric survival models were used to examine the effect of treatment on survival, adjusted for age, sex, and comorbidities. RESULTS: 294 patients in Ohio and 1,097 patients in Taiwan met the inclusion criteria. 70.3% patients in Ohio and 51.4% in Taiwan received surgical resection, followed by concurrent chemoradiation. Patients who received this treatment had the highest survival rate, with a 1-year survival rate of 72.8% in Ohio and 73.4% in Taiwan. Patients who did not receive surgical resection, followed by concurrent chemoradiation had an increased risk of death (hazard ratio of 5.03 [95% confidence interval (CI): 3.61-7.02] in Ohio and 1.49 [95% CI: 1.31-1.71] in Taiwan) after adjustment for age, sex, and comorbidities. CONCLUSION: Surgical resection followed by concurrent chemoradiation was associated with higher survival rate of patients with high grade glioma in both Ohio and Taiwan; however, one-third of patients in Ohio and half in Taiwan did not receive this treatment.

Association between genetic polymorphisms of PTGS2 and glioma in a Chinese population.

Several previous studies indicated that genetic polymorphisms in inflammatory factor genes were associated with glioma risk. However, the relationship between the prostaglandin-endoperoxide synthase 2 (PTGS2) genetic polymorphism and glioma remains unclear in the Chinese population. We selected 199 histologically confirmed adult glioma patients and 199 cancer-free controls for the present study and analyzed the distribution of the PTGS2 genotypes and haplotypes. We found that the CC+CT genotype of rs5275 was common in the control group but not in the glioma group (P = 0.033). In addition, we found that the frequency of the C allele was higher in the control group than in the glioma group (P = 0.014). For rs6681231, although we found no significant difference between the 2 groups in genotype distribution, we found that the frequency of the C allele was lower in glioma patients than in control subjects (P = 0.044). We found no significant difference between these 2 groups in the rs689466 genotype and allele distributions. Haplotype analysis suggested that the frequency of the C-A-C haplotype was significantly lower in glioma patients than in control subjects [P = 0.028, odds ratio (OR) = 0.628, 95% confidence interval (CI) = 0.413-0.955]. However, the frequency of the T-A-G haplotype was higher in glioma patients than in control subjects (P = 0.036, OR = 1.418, 95%CI = 1.022-1.967). Therefore, polymorphisms in the PTGS2 gene may be associated with glioma susceptibility in the Chinese population.

The survival of patients with high grade glioma from different ethnic groups in South East England.

Studies in the United States (US) have reported varying treatment and survival for patients with high grade glioma from different ethnic groups. This study investigates for the first time whether differences also exist in the United Kingdom (UK). This population-based cohort study used cancer registration data for 4,845 patients diagnosed in South East England between 2000 and 2009. Linked self-assigned ethnicity data within Hospital Episode Statistics were used to define White, Indian, Pakistani, Bangladeshi, Black Caribbean, Black African, Other and Not known groups. Logistic regression was used to generate odds ratios for a record of receipt of treatment (surgery, radiotherapy and chemotherapy), adjusting for sex, age, morphology, socioeconomic deprivation and comorbidity in each ethnic group. Hazard ratios were generated using Cox regression, adjusting for sex, age, morphology, socioeconomic deprivation, comorbidity and treatment. The overall one-year survival was 28.4 %. Ethnicity data was available for 3,793 (78 %) patients. Receipt of treatment was generally similar between different ethnic groups after adjustment for sex, age, morphology, socioeconomic deprivation and comorbidity. After adjustment for potential confounders, the Indian (HR 0.72, p = 0.037) and Other groups (HR 0.76, p = 0.003) had better survival, while the Not known group (HR 1.34, p < 0.0001) had worse survival than the White group. Patients from UK Indian groups have better survival than White patients while those from Black ethnic groups appear to have similar survival to White patients. These findings suggest the need to investigate possible contributing factors including the completeness of follow-up, clinical performance status and tumour biology.

Association between telomerase reverse transcriptase rs2736100 polymorphism and risk of glioma.

BACKGROUND: Epidemiological studies have been conducted to investigate the association of telomerase reverse transcriptase (TERT) rs2736100 polymorphism with glioma risk. The aim of the present study was to evaluate the association of TERT rs2736100 polymorphism with glioma risk using a meta-analysis approach. MATERIALS AND METHODS: All eligible studies were identified through a search of PubMed, EMBASE, China National Knowledge Infrastructure, Database of Chinese Scientific and Technical Periodicals, and China Biology Medical literature database before January 2014. The association between the TERT rs2736100 polymorphism and glioma risk was estimated by odds ratio (OR) and 95% confidence interval (CI). RESULTS: A total of nine case-control studies including 9411 cases and 13,708 controls were eventually collected. Overall, we found that TERT rs2736100 polymorphism was significantly associated with the risk of glioma (OR = 1.29, 95% CI 1.24-1.34, P < 0.001). In the subgroup analysis based on ethnicity, the significant association was found in Caucasians (OR = 1.29, 95% CI 1.24-1.34, P < 0.001). In subgroup analyses by histology, the associations were significant in glioblastoma (OR = 1.45, 95% CI 1.32-1.60, P < 0.001), astrocytoma (OR = 1.41, 95% CI 1.26-1.58, P < 0.001), and oligodendroglioma (OR = 1.20, 95% CI 1.05-1.37, P = 0.008). CONCLUSIONS: Taken together, these data suggested that TERT rs2736100 polymorphism may contribute to glioma susceptibility.

Association of ERCC1 C8092A and ERCC2 Lys751Gln polymorphisms with the risk of glioma: a meta-analysis.

OBJECTIVES: To comprehensively evaluate the association of ERCC1 C8092A and ERCC2 Lys751Gln polymorphisms with the risk of glioma. METHODS: Potential studies were searched and selected through the Pubmed/MEDLINE, EMBASE, the China National Knowledge Infrastructure (CNKI) platforms, WanFang and VIP database up to June 2013. Two investigators independently reviewed full text and included studies met inclusion criteria. Combined odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated in a fixed-effects model or a random-effects model according to results of heterogeneity test. All analyses were performed by Revman 5.2 and Stata 10.0 software. RESULTS: A total of 10 studies were included in our meta-analysis, including 3,580 glioma patients and 4,728 controls. Overall, ERCC1 C8092A polymorphism was associated with the risk of glioma (AA vs. CC: OR = 1.29, 95%CI: 1.07-1.55, P = 0.01; recessive model: OR = 1.29; 95% CI: 1.07-1.55, P = 0.01). When stratified by ethnicity, significant association was only observed in the Chinese population (AA vs. CC: OR = 1.37, 95%CI: 1.03-1.81, P = 0.03; recessive model: OR = 1.34; 95% CI: 1.02-1.75, P = 0.04). For ERCC2 Lys751Gln polymorphism, no significant association was found between ERCC2 Lys751Gln polymorphism and the risk of glioma in different genetic models. A significant association of ERCC2 Lys751Gln polymorphism with the risk of glioma was identified in the Caucasian population under recessive model (OR = 0.87; 95% CI: 0.78-0.98, P = 0.02), but not in the Chinese population. CONCLUSION: This meta-analysis suggested that the AA genotype of ERCC1 C8092A polymorphism might increase the susceptibility of glioma in the Chinese population. And the TT genotype of ERCC2 Lys751Gln polymorphism may decrease the risk of glioma in the Caucasian population. But the small number of studies and moderate methodological quality require cautious interpretation of the study results.

Quantitative assessment of the association between +61A>G polymorphism of epidermal growth factor gene and susceptibility to glioma.

Numerous studies have investigated the risk of cancer associated with the polymorphism of epidermal growth factor (EGF) 61A>G, but results have been inconsistent. We performed this meta-analysis to drive a more precise estimation of the association between this polymorphism and risk of glioma. A comprehensive search was conducted to identify all case-control studies on the EGF +61A>G polymorphism and glioma risk. Odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated to assess the strength of the association. Statistical analysis was performed with the software program Stata (version 12.0). A total of ten eligible studies, including 1,888 cases and 2,836 controls were included in this work. Overall, there was a significant association between EGF +61A>G polymorphism and glioma risk in the allele model (OR = 1.419, 95% CI = 1.144-1.759, P = 0.001). In the subgroup analysis by ethnicity, significant associations were also found in Asian populations under all different genetic models (homozygote model: OR = 1.727, 95% CI = 1.310-2.275, P = 0.000; heterozygote model: OR = 1.202, 95% CI = 1.023-1.413, P = 0.025; dominant model: OR = 1.279, 95% CI = 1.096-1.491, P = 0.002; recessive model: OR = 1.590, 95% CI = 1.221-2.070, P = 0.001; and A-allele versus G-allele OR = 1.600, 95% CI = 1.145-2.236, P = 0.006). However, no significant associations were found among Caucasians in all comparison models. In conclusion, the results suggest that there is a significant association between EGF +61A>G polymorphism and glioma risk among Asians.

Association between GSTP1 Ile105Val polymorphism and glioma risk: a systematic review and meta-analysis.

Glutathione S-transferase P1 (GSTP1) gene Ile105Val polymorphism has been suggested to be involved in the development of glioma. However, the results from the studies regarding the association between GSTP1 Ile105Val polymorphism and glioma risk have been inconsistent. Thus, we performed a meta-analysis to investigate this association. Pooled odds ratios (ORs) with 95% confidence intervals (95%CIs) were calculated using random or fixed effects model. Nine studies with 2,078 cases and 3,970 controls were finally included into this meta-analysis. The results suggested there was no association between GSTP1 Ile105Val polymorphism and glioma risk under recessive model (OR = 1.138, 95%CI = 0.966-1.341, Pheterogeneity = 0.088, P = 0.123). Subgroup analyses by ethnicity showed there was also no association between GSTP1 Ile105Val polymorphism and glioma risk in mixed populations under recessive model (OR = 1.199, 95%CI = 0.928-1.549, Pheterogeneity = 0.060, P = 0.166) and Caucasian populations (OR = 1.097, 95%CI = 0.885-1.360, Pheterogeneity = 0.186, P = 0.398). In conclusion, the meta-analysis suggests that there is no association between GSTP1 Ile105Val polymorphism and glioma risk. However, more well-designed and larger studies are needed to further assess this association.