Association of a LSP1 gene rs3817198T>C polymorphism with breast cancer risk: evidence from 33,920 cases and 35,671 controls

Published data on the association between lymphocyte-specific protein 1 (LSP1) rs3817198T>C polymorphism and breast cancer risk are inconclusive. Hence, we conducted a meta-analysis of the LSP1 gene and risk of breast cancer to obtain the most reliable estimate of the association. PubMed, Embase and Web of Science databases were searched. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were extracted and pooled to assess the strength of the association between the LSP1 rs3817198T>C polymorphism and risk of breast cancer. A total of seven eligible studies including 33,920 cases and 35,671 controls based on the search criteria were involved in this meta-analysis. The distributions of genotypes in the controls were all in agreement with Hardy–Weinberg equilibrium. We observed that the LSP1 rs3817198T>C polymorphism was significantly correlated with breast cancer risk when all studies were pooled into the meta-analysis (the allele contrast model: OR = 1.06, 95% CI = 1.04–1.08; the homozygote codominant: OR = 1.14, 95% CI = 1.01–1.28). In the stratified analysis by ethnicity, significant association was observed in Caucasians for CC versus TT homozygote codominant model (OR = 1.25; 95% CI = 1.03–1.52) and for the recessive model (OR = 1.22; 95% CI = 1.02–1.47). There was significant association observed in Africans for CC versus TT homozygote codominant model (OR = 0.45; 95% CI = 0.22–0.92) and for the recessive model (OR = 0.43; 95% CI=0.22–0.88). Also, significant association was observed in mixed ethnicities for CC versus TT homozygote codominant model (OR = 1.12; 95% CI = 1.05–1.19). When stratified by study design, statistically significantly elevated risk was found in nested case–control studies (CC vs. TT: OR = 1.12, 95% CI = 1.05–1.19). But no significant association was observed for all comparison models between LSP1 rs3817198T>C polymorphism and breast cancer risk in hospital-based and people-based studies. When stratified by BRCA1 mutation carriers status, statistically significantly elevated risk was found in this meta-analysis (the allele contrast model: OR = 1.07, 95% CI = 1.01–1.14; the dominant model: OR = 1.09, 95% CI = 1.00–1.18). And significant association was found in the BRCA2 mutation carriers in the allele contrast (OR = 1.11, 95% CI = 1.03–1.20), the homozygote codominant (OR = 1.23, 95% CI = 1.04–1.47), the heterozygote codominant (OR = 1.12, 95% CI = 1.00–1.25) and the dominant models (OR = 1.14, 95% CI = 1.03–1.27). There was significant association between LSP1 rs3817198T>C polymorphism and breast cancer risk in BRCA1 and BRCA2 positive cohort in all comparison models (the allele contrast model: OR = 1.08, 95% CI = 1.03–1.13; CC vs. TT: OR = 1.16, 95% CI = 1.05–1.29; TC vs. TT: OR = 1.09, 95% CI = 1.01–1.16; the dominant model: OR = 1.10, 95% CI = 1.03–1.17; the recessive model: OR = 1.12, 95% CI = 1.01–1.23). In conclusion, this meta-analysis suggests that the LSP1 rs3817198T>C polymorphism is a low-penetrant risk factor for developing breast cancer but may not be in Africans.     

XPA A23G polymorphism and susceptibility to cancer: a meta-analysis

Xeroderma pigmentosum group A (XPA) participates in modulating recognition of DNA damage during the DNA nucleotide excision repair process. The XPA A23G polymorphism has been investigated in case–control studies to evaluate the cancer risk attributed to the variant, but the results were conflicting. To clarify the effect of XPA A23G polymorphism in cancer risk, we conducted a meta-analysis that included 30 published case–control studies. Overall, no significant association of XPA A23G variant with cancer susceptibility was observed for any genetic model. However, significant association was observed for colorectal cancer (GG vs. AA: OR = 1.68, 95% CI = 1.15–2.44; dominant genetic model GG + AG vs. AA: OR = 1.54, 95% CI = 1.08–1.17), for breast cancer an increased but non-significant risk was found (GG vs. AA: OR = 1.27, 95% CI = 0.98–1.66; dominant genetic model GG + AG vs. AA: OR = 1.27, 95% CI = 0.99–1.63), and for head and neck cancer an increased risk was observed in recessive model (OR = 1.19, 95% CI = 1.02–1.38), whereas for lung cancer a significant reduced risk was observed (GG vs. AA: OR = 0.77, 95% CI = 0.66–0.90; dominant genetic model GG + AG vs. AA: OR = 0.76, 95% CI = 0.66–0.87), it’s noting that in Asian population the inverse association was more apparent. In addition, in Asian population for esophageal cancer a significant decreased risk was also found in dominant genetic model (OR = 0.55; 95% CI = 0.43–0.70) and for head and neck cancer an increased risk was observed in dominant genetic model (OR = 1.51, 95% CI = 1.03–2.23). The meta-analysis suggested that the XPA A23G G allele is a low-penetrant risk factor for cancer development.     

Association between ATM polymorphisms and cancer risk: a meta-analysis

To date, epidemiological studies have assessed the association between Ataxia-telangiectasia mutated (ATM) gene polymorphisms and cancer risk, including lung cancer, breast cancer, glioma and pancreatic cancer. However, the results of these studies remain controversial. We aimed to examine the associations between two SNPs (rs664143 and rs664677) and cancer risk by conducting a meta-analysis of case–control studies. A total of 12 publications were included in this meta-analysis, 8 for rs664143 and 7 for rs664677. Overall, rs664143 heterozygote carriers turned out to be associated with cancer risk (OR = 1.18, 95% CI 1.02–1.36). In the subgroup analysis by cancer type, we observed that the ATM rs664143 polymorphism was significantly associated with lung cancer risk (GA vs. GG: OR = 1.48, 95% CI 1.18–1.85, AA vs. GG: OR = 1.51, 95% CI 1.18–1.93) and rs664677 polymorphism was associated with decreased lung cancr risk and increased breast cancer risk (for lung cancer: TC vs. TT: OR = 0.76, 95% CI 0.62–0.92, CC vs. TT: OR = 0.80, 95% CI 0.64–0.99 and for breast cancer: TC vs. TT: OR = 1.42, 95% CI 1.17–1.73, CC vs. TT: OR = 1.51, 95% CI 1.21–1.87). In the subgroup analysis by region, we also observed that individuals with ATM rs664143 GA or AA genotype had an obvious increased cancer risk among Asian people (GA vs. GG: OR = 1.40, 95% CI 1.20–1.63, AA vs. GG: OR = 1.37, 95% CI 1.16–1.62). In conclusion, ATM rs664143 polymorphism was associated with cancer susceptibility. ATM rs664143 polymorphism was significantly associated with lung cancer risk. ATM rs664677 polymorphism was associated with decreased lung cancer risk as well as increased breast cancer risk.     

The MDM2 309T>G Polymorphism and Ovarian Cancer Risk: A Meta-Analysis of 1534 Cases and 2211 Controls

Background

Recently, there have been a number of studies on the association between MDM2 (Murine Double Minute 2) 309 polymorphism and ovarian cancer risk. However, the results of previous reports remain controversial and ambiguous. Thus, we performed a meta-analysis to explore more precisely the association between MDM2 309 polymorphism and the risk of ovarian cancer.

Methods

A meta-analysis was performed to examine the association between MDM2 309T>G polymorphism and ovarian cancer risk. Odds ratio (OR) and its 95% confidence interval (CI) were used for statistical analysis.

Results

Our publication search identified a total of 6 studies with 1534 cases and 2211 controls. No significant association was found between MDM2 309T>G polymorphism and ovarian cancer risk in total population analysis. In the subgroup meta-analysis by ethnicity, a negative association was shown in Asian subgroup (G vs. T OR = 0.774, 95% CI = 0.628–0.955, P = 0.017, P _het = 0.327; GG vs. TT: OR = 0.601, 95% CI = 0.395–0.914, P = 0.017, P _het = 0.417; dominant model TG+GG vs. TT: OR = 0.661, 95% CI = 0.468–0.934, P = 0.019, P _het = 0.880), and no significant association in any genetic models among Caucasians was observed.

Conclusions

This meta-analysis provides evidence for the association between MDM2 309 polymorphism and ovarian cancer risk, supporting the hypothesis that MDM2 SNP309 G allele acts as an important ovarian cancer protective factor in Asians but not in Caucasians.     

Survivin promoter ?31G/C (rs9904341) polymorphism and cancer susceptibility: a meta-analysis

This study aimed to perform a meta-analysis to assess the association of survivin −31 G/C promoter polymorphism and cancer risk. Thirteen case–control studies identified through PubMed and published between 2007 and 2011 with a total of 3329 cancer cases and 3979 controls were included in this meta-analysis. Odds ratio (OR) and 95% confidence interval (95% CI) were used to investigate the strength of the association. Overall, the pooled analysis showed that survivin −31C allele was associated with 1.27 fold increased risk of cancer compared with the −31G allele (95% CI = 1.091–1.479; random model). Subgroup analyses based on type of cancer and ethnicity were also performed, and results indicated that survivin −31G/C polymorphism was not associated with risk of gastric cancer [OR = 2.879; 95% CI = 0.553–15.004) for CC vs.GG] and esophageal cancer [OR = 1.352; 95% CI = 0.494–3.699) for CC vs.GG]. Stratification on the basis of ethnicity showed that the risk due to −31C allele was significant only in Asian population [OR = 1.894; 95% CI = 1.206–2.974 for CC vs.GG]. The present meta-analysis suggests an important role of survivin −31 G/C polymorphism with cancer risk especially in Asian population. However, further studies with larger sample size are required to draw more comprehensive conclusions and provide more precise evidence in individual cancers.     

Current evidences on vascular endothelial growth factor polymorphisms and breast cancer susceptibility

Several polymorphisms of vascular endothelial growth factor (VEGF) such as 936 C/T, −2578 C/A, −406 C/T, and −1154 G/A polymorphism have been identified. Published data on the association between VEGF polymorphisms and breast cancer risk are inconclusive. To derive a more precise estimation of the relationship, a meta-analysis was performed. Crude OR with 95% CI was used to assess the strength of association between them. For VEGF 936C/T polymorphism, a total of 10 studies including 7,685 cases and 7,915 controls were involved in this meta-analysis. Overall, no significant associations were found between VEGF 936C/T polymorphism and breast cancer risk when all studies pooled into the meta-analysis (TC vs. CC: OR = 0.904, 95% CI = 0.797–1.024; TT vs. CC: OR = 0.974, 95% CI = 0.786–1.205; dominant model: OR = 0.911, 95% CI = 0.811–1.024; and recessive model: OR = 0.991, 95% CI = 0.801–1.226). In the subgroup analysis by ethnicity, still no significant associations were found for all comparison models. For −2578 C/A, −406 C/T, and −1154 G/A polymorphism, there were too limited data to perform a meta-analysis. In conclusion, this meta-analysis suggests that the VEGF 936C/T polymorphism may be not associated with breast cancer development. However, large sample and representative population-based studies with homogeneous breast cancer patients and well matched controls are warranted to confirm this finding.     

The Ku70 ?1310C/G promoter polymorphism is associated with breast cancer susceptibility in Chinese Han population

Ku70 plays an important role in the DSBR (DNA double-strand breaks repair) and maintenance of genomic integrity. Genetic variations within human Ku70 have been demonstrated to be associated with increased risk of several types of cancers. In this hospital-based case–control study, we aimed to investigate whether a single nucleotide polymorphism (SNP) in the promoter region (rs2267437) of Ku70 gene is associated with susceptibility to breast cancer in Chinese Han population. A total of 293 patients with breast cancer and 301 age-matched healthy controls were enrolled in this study. The Ku70 −1310C/G polymorphism was determined by polymerase chain reaction-restriction fragment length polymorphism (PCR–RFLP) analysis. A significant difference in genotype distribution and allele frequency was observed between patients and controls. The CG or GG carries were at higher risk of breast cancer compared with the CC homozygotes (OR = 1.43, 95% CI = 1.02–2.00, P = 0.038 and OR = 3.53, 95% CI = 1.60–7.80, P = 0.002, respectively). Further stratification analysis revealed that G allele was associated with an increased risk of breast cancer among premenopausal women (OR = 1.68, 95% CI = 1.21–2.33, P = 0.002), but not in postmenopausal women (OR = 1.33, 5% CI = 0.85–2.10, P = 0.216). Our study suggests that the Ku70 −1310C/G promoter polymorphism may be a susceptibility factor for breast cancer in Chinese Han population.     

Quantitative assessment of the effect of MTHFR polymorphisms on the risk of lung carcinoma

Published studies on the relationships between 5,10-methylenetetrahydrofolate reductase (MTHFR) polymorphisms and lung cancer risk have been conflicting. To derive a more precise estimation of the relationship, a meta-analysis was performed. Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated to assess the association between MTHFR C677T and A1298C polymorphisms and lung cancer risk. A total of 15 studies including 10,753 cases and 11,275 controls described C677T genotypes, among which 11 articles totalling 6,161 cases and 7,684 controls described A1298C genotypes, were also involved in this meta-analysis. Overall, no significantly elevated lung cancer risk was found in any genetic models when all studies were pooled. For C677T polymorphism: (TT vs. CC: OR = 1.17, 95% CI = 0.97–1.42; TC vs. CC: OR = 1.06, 95% CI = 0.94–1.20; dominant model: OR = 1.09, 95% CI = 0.96–1.24; and recessive model: OR = 1.08, 95% CI = 0.95–1.24); for A1298C polymorphism: (CC vs. AA: OR = 1.04, 95% CI = 0.91–1.19; AC vs. AA: OR = 0.98, 95% CI = 0.91–1.06; dominant model: OR = 0.99, 95% CI = 0.92–1.06; and recessive model: OR = 1.05, 95% CI = 0.92–1.20). In the subgroup analyses, the results showed that 677T varients could decrease lung cancer risk in female (OR = 0.63, 95% CI = 0.41–0.95, P-value = 0.03, 677CC as reference). No evidence of any associations of MTHFR A1298C polymorphism with lung cancer was found in overall or subgroup analyses. Our meta-analysis supports that the common polymorphisms of C677T and A1298C in MTHFR gene are not susceptibility gene for lung cancer from currently available evidence.     

MDM2 SNP309 rs2279744 Polymorphism and Gastric Cancer Risk: A Meta-Analysis

Background

MDM2 is a major negative regulator of p53, and a single nucleotide polymorphism (SNP) in the MDM2 promoter region SNP309 has been demonstrated to be associated with an increased MDM2 expression and a significantly earlier age of onset of several tumors, including gastric cancer. Several studies were published to evaluate the association between SNP309 and gastric cancer risk. However, the results remain conflicting rather than conclusive.

Objective

The aim of this study was to assess the association between the MDM2 SNP309 polymorphism and gastric risk.

Methods

We performed a meta-analysis to investigate this relationship. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the strength of the association. The pooled ORs were performed for codominant model, dominant model, and recessive model, respectively.

Results

Five published case-control studies, including 1,621 gastric cancer cases and 2,639 controls were identified. We found that the MDM2 SNP309 polymorphism was associated with a significantly increased risk of gastric cancer risk when all studies were pooled into the meta-analysis (GG versus TT, OR = 1.54; 95%CI = 1.04–2.29, and GG versus GT/TT, OR = 1.49, 95%CI = 1.30–1.72). Furthermore, Egger''s test did not show any evidence of publication bias (P = 0.799 for GG versus TT).

Conclusion

Our results suggest that the MDM2 SNP309 polymorphism may be a low-penetrant risk factor for the development of gastric cancer.     

MDM2 SNP309 contributes to tumor susceptibility: a meta-analysis

The potentially functional polymorphism,SNP309,in the promoter region of MDM2 gene has been implicated in cancer risk,but individual published studies showed inconclusive results.To obtain a more precise estimate of the association between MDM2 SNP309 and risk of cancer,we performed a meta-analysis of 70 individual studies in 59 publications that included 26,160 cases with different types of tumors and 33,046 controls.Summary odds ratios (OR) and corresponding 95％ confidence intervals (CIs) were estimated using fixed- and random-effects models when appropriate.Overall,the variant genotypes were associated with a significantly increased cancer risk for all cancer types in different genetic models (GG vs.TT:OR,1.123; 95％ CI,1.056-1.193; GG/GT vs.TT:OR,1.028; 95％ CI,1.006-1.050).In the stratified analyses,the increased risk remained for the studies of most types of cancers,Asian populations,and hospital-/population-based studies in different genetic models,whereas significantly decreased risk was found in prostate cancer (GG vs.TT:OR,0.606; 95％ CI,0.407-0.903; GG/GT vs.TT:OR,0.748; 95％ CI,0.579-0.968).In conclusion,the data of meta-analysis suggests that MDM2 SNP309 is a potential biomarker for cancer risk.     

<Emphasis Type="Italic">TGFBR1</Emphasis>*6A/9A polymorphism and cancer risk: a meta-analysis of 13,662 cases and 14,147 controls

Published data on the association between TGFBR1*6A/9A polymorphism and cancer risk are inconclusive. To derive a more precise estimation of the relationship, a meta-analysis was performed. A total of 32 studies including 13,662 cases and 14,147 controls were involved in this meta-analysis. Overall, significantly elevated cancer risks were associated with TGFBR1*6A in all genetic models (for allelic effect: OR = 1.11; 95% CI = 1.03–1.21; for 6A/6A vs. 9A/9A: OR = 1.30; 95% CI = 1.01–1.69; for 9A/6A vs. 9A/9A: OR = 1.08; 95% CI = 1.01–1.15; for dominant model: OR = 1.08; 95% CI = 1.02–1.15; for recessive model: OR = 1.29; 95% CI = 1.00–1.68). In the subgroup analysis by cancer types, significant associations were found in breast cancer (for allelic effect: OR = 1.16; 95% CI = 1.01–1.34) and ovarian cancer (for allelic effect: OR = 1.24; 95% CI = 1.00–1.54; for 6A/6A vs. 9A/9A: OR = 2.34; 95% CI = 1.03–5.33). However, no significant associations were found in colorectal cancer, bladder cancer, prostate cancer and lung cancer for all genetic models. In summary, this meta-analysis suggests that the TGFBR1*6A/9A polymorphism is associated with cancer susceptibility, increasing the risk of breast and ovarian cancer.     

Association between ATM 5557G>A polymorphism and breast cancer risk: a meta-analysis

Epidemiological studies have evaluated the association between ATM 5557G>A (p.D1853N) polymorphism and breast cancer risk. However, the results remain conflicting rather than conclusive. To derive a more precise estimation of the relationship, we performed this meta-analysis. Systematic searches of PubMed and Medline databases were performed. A total of nine studies included 3155 cases and 2752 controls were identified. When all nine studies were pooled into the meta-analysis, there was no evidence for significant association between 5557G>A mutation and breast cancer risk(for G/A vs. G/G: OR = 1.05, 95% CI = 0.83–1.34; for A/A vs. G/G: OR = 0.77, 95% CI = 0.58–1.03; for dominant model: OR = 1.04, 95% CI = 0.82–1.31; for recessive model: OR = 0.87, 95% CI = 0.69–1.09). In the subgroup analyses by family history and ethnicity, significant associations were found among Amerindians (for G/A vs. G/G: OR = 2.19, 95% CI = 1.38–3.47; for dominant model: OR = 2.15, 95% CI = 1.37–3.38). In summary, the meta-analysis suggest that ATM 5557G>A polymorphism is associated with increased breast cancer risk among Amerindians. However, due to the small subjects included in analysis and the selection bias existed in some studies, the results for Amerindians should be interpreted with caution.     

A genetic variant in microRNA-196a2 is associated with increased cancer risk: a meta-analysis

MicroRNAs (miRNAs) are small non-coding RNA molecules that function as negative regulators of gene expression. Common genetic variants (single nucleotide polymorphisms, SNPs) in miRNA genes may alter their expression or maturation resulting in varied functional consequences. Until now, several studies had evaluated the association between the polymorphisms in the hsa-miR-196a2 rs11614913 and cancer risk in diverse populations and in multiple types of cancer, with contradictory outcomes. Therefore, here we performed a meta-analysis to address the association between this polymorphism and cancer risk. A total of nine studies involving 6,540 cases and 7,562 controls were retrieved based on PubMed. Our analysis demonstrated that hsa-miR-196a2 rs11614913 CC genotype significantly increased the cancer risk in homozygote comparison model compared to TT genotype (OR = 1.18; 95% CI, 1.01–1.68). Moreover, significant association of this polymorphism with breast cancer was found based on homozygote comparison model (OR = 1.30; 95% CI, 1.01–1.26) and dominant model (OR = 1.11; 95% CI, 1.01–1.23). In addition, hsa-miR-196a2 rs11614913 CC genotype was significantly associated with cancer risk in Chinese and Indian (OR = 1.21; 95% CI, 1.05–1.40), but not in Caucasians (OR = 1.03; 95% CI, 0.89–1.19). Taken together, our results indicate that the polymorphism of hsa-miR-196a2 rs11614913 is associated with cancer susceptibility, especially with breast cancer and in Chinese and Indian populations.     

Association between the XRCC3 polymorphisms and breast cancer risk: meta-analysis based on case–control studies

The previous published data on the association between X-ray repair cross-complementing group 3 (XRCC3) T241M, A4541G, and A17893G polymorphisms and breast cancer risk remained controversial. Hence, we performed a meta-analysis to investigate the association between breast cancer and XRCC3 T241M (21,910 cases and 23,961 controls), A4541G (9,633 cases and 10,994 controls), and A17893G polymorphisms (10,761 cases and 12,235 controls) in different inheritance models. When all the eligible studies were pooled into the meta-analysis of XRCC3 T241M polymorphism, significantly increased risk of breast cancer was observed in recessive model (odds' ratio [OR] = 1.10, 95% confidence interval [CI] = 1.04–1.16) and in additive model (OR = 1.10, 95% CI = 1.03–1.16). No significant association was found between A4541G polymorphism and breast cancer risk. When all the eligible studies were pooled into the meta-analysis of XRCC3 A17893G polymorphism, no significant association was found in any genetic model. Additionally, when one study was deleted in the sensitive analysis, the results of XRCC3 A17893G were changed in the additive model (OR = 0.90, 95% CI = 0.82–0.99) and dominant model (OR = 0.94, 95% CI = 0.89–0.99). In summary, this meta-analysis indicates that T241M polymorphism show an increased breast cancer risk and A17893G polymorphism may be associated with decreased breast cancer risk. A study with the larger sample size is needed to further evaluated gene-environment interaction on XRCC3 T241M, A4541G, and A17893G polymorphisms and breast cancer risk.     

CXCL12 G801A polymorphism and breast cancer risk: a meta-analysis

The G801A polymorphism in the CXCL12 gene has been implicated in breast cancer risk. However, the published findings are inconsistent. We therefore performed a meta-analysis to investigate this relationship. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the strength of the association. The pooled ORs were performed for codominant model, dominant model, and recessive model, respectively. Five published case–control studies, including 1,058 breast cancer cases and 1,023 controls were identified. No study had a deviation from the Hardy–Weinberg equilibrium (HWE) in controls. We found that the CXCL12 G801A (rs1801157) polymorphism was associated with a significantly increased risk of breast cancer risk when all studies were pooled into the meta-analysis (codomiant model: AA versus GG, OR = 1.64, 95% CI = 1.16–2.33; GA versus GG, OR = 1.42, 95% CI = 1.18–1.71; dominant model: AA/GA versus GG, OR = 1.44, 95% CI = 1.21–1.72). Furthermore, Egger’s test did not show any evidence of publication bias (P > 0.05 for the dominant model). In conclusion, the results suggest that the CXCL12 G801A polymorphism may be a low-penetrant risk factor for developing breast cancer.     

DNMT3B polymorphisms and cancer risk: a meta analysis of 24 case–control studies

The association between polymorphism of DNA methyltransferases 3B and cancer risk has been widely studied recently, and no consensus conclusion is available up to now. We perform a comprehensive search using the databases of Medline, ISI Web of Knowledge and Embase. The odds ratio (OR) and its 95% confidence interval (95% CI) are used to investigate the strength of the association. A total of 24 case–control studies with 15,647 individuals are included in this meta-analysis. For −149C > T (17 studies, 5229 cases and 6910 controls), no evidence indicate that individuals carrying the variant genotypes (CC + CT), relative to those carrying the wild homozygote TT genotype, have an increased risk of cancer (OR = 1.03; 95% CI = 0.84–1.26; P = 0.76). Similarly, no cancer risk is found in the subgroup analyses. For −579G > T (11 studies, 3513 cases and 3714 controls), significantly decreased risks of cancer are observed, and the ORs (95% CI) are 0.70 (0.56–0.87) for GT versus TT, 0.70 (0.57–0.85) for GG + GT versus TT and 0.76 (0.63–0.93) for G-allele versus T-allele, respectively. Subgroup analyses stratified by ethnicity and types of cancer are also performed, and results indicated that −579G > C polymorphism is associated with risk of cancer in Asians [0.68 (0.53–0.87) for GT vs. TT] but not in Europeans [0.82 (0.63–1.07) for GT vs. TT]. We also observe that the −579G is associated with decreased risk of colorectal cancer [0.49(0.38–0.62) for GT vs. TT]. More studies with larger sample size were needed to provide more precise evidence.     

Combined analysis of the association between p73 G4C14-to-A4T14 polymorphisms and cancer risk

P73 is a structural and functional homologue of p53, and plays an important role in regulating cell cycle and apoptosis. A potentially functional polymorphism (designated as p73 G4C14-to-A4T14) has been identified in a region in exon 2 of the p73 gene, which may theoretically form a stem-loop structure and thereby affect p73 expression. Several investigations have reported the correlation between p73 G4C14-to-A4T14 polymorphism and cancer risk. However, the results are inconclusive. To further assess the association between p73 polymorphism and cancer risk, we performed meta-analysis of the data sets obtained from 26 individual studies involving 8,148 cancer patients and 8,150 controls. The association between p73 G4C14-to-A4T14 polymorphism and cancer risk was determined by crude odd ratios (OR) with 95% CI (confidential interval). AT-allele carriers were found to have a significantly increased risk of cervical cancer (AT/GC vs. GC/GC, OR = 1.63, 95% CI = 1.14–2.33; AT/AT + AT/GC vs. GC/GC, OR = 1.49, 95% CI = 1.05–2.10), colorectal cancer (AT/AT vs. AT/GC + GC/GC, OR = 1.98, 95% CI = 1.25–3.12), head and neck cancer (AT/AT + AT/GC vs. GC/GC, OR = 1.44, 95% CI = 1.06–1.96) and other cancers (AT/AT vs. GC/GC, OR = 1.78, 95% CI = 1.24–2.57; AT/AT vs. AT/GC + GC/GC, OR = 1.80, 95% CI = 1.26–2.56). In the stratified analysis of ethnicity, a significantly elevated cancer risk was found in Caucasians (AT/AT + AT/GC vs. GC/GC, OR = 1.18, 95% CI = 1.08–1.30; allele AT vs. allele GC, OR = 1.15, 95% CI = 1.06–1.24). No significant association of p73 polymorphism with the cancer risk of smoking was detected by stratified analysis by smoking status. Together, our data suggest that the p73 G4C14-to-A4T14 may be a risk factor of cancer especially in Caucasians.     

CYP2E1 Rsa I/Pst I polymorphism contributes to oral cancer susceptibility: a meta-analysis

Previous data on association between CYP2E1 Rsa I/Pst I polymorphism and oral cancer risk were controversial. To investigate the association between CYP2E1 Rsa I/Pst I polymorphism and oral cancer risk. We performed a meta-analysis to assess the relationship between oral cancer and genotype with English language until June 2010. Twelve published case–control studies of 1259 patients with oral cancer and 2262 controls were acquired. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of the association in codominant and dominant models. Overall, the pooled ORs indicated a significant association between CYP2E1 Rsa I/Pst I polymorphism and oral cancer risk (for c1/c2 vs. c1/c1: OR = 1.30, 95% CI = 1.04–1.62, P_{heterogeneity} = 0.57; for (c1/c2 + c2/c2) vs. c1/c1: OR = 1.32, 95% CI = 1.07–1.64, P_{heterogeneity} = 0.57, respectively). In subgroup analysis by race, the same significant risks were found among Asian (for c1/c2 vs. c1/c1: OR = 1.41, 95% CI = 1.05–1.91, P_{heterogeneity} = 0.92; for (c1/c2 + c2/c2) vs. c1/c1: OR = 1.43, 95% CI = 1.08–1.88, P_{heterogeneity} = 0.97, respectively). In conclusion, this meta-analysis demonstrates that CYP2E1 Rsa I/Pst I c2 allele may be a biomarker for oral cancer, especially among Asian populations.     

Association of C47T polymorphism in <Emphasis Type="Italic">SOD2</Emphasis> gene with coronary artery disease: a case–control study and a meta-analysis

Oxidative damage promotes atherosclerosis. SOD2 is an important antioxidant enzyme. A case–control study and a meta-analysis were performed to assess the association of C47T polymorphism in SOD2 gene with premature, late-onset and overall coronary artery disease (CAD) risk. A hospital-based case–control study was conducted with 269 premature CAD cases, 278 late-onset CAD cases and 299 healthy controls. Polymerase chain reaction (PCR) and Pyrosequencing were used to detect the polymorphism. Multinomial logistic regression model was performed to estimate odds ratio (OR) with 95% confidence intervals (CIs) and adjust potential confounders. A meta-analysis was performed using eight outcomes including our result. Fixed or random effect pooled measure was selected on the basis of homogeneity test among studies. Heterogeneity among studies was evaluated using I ². Meta-regression was used to explore potential sources of between-study heterogeneity. Publication bias was estimated using Peters’s linear regression test. In our case–control study, compared with the TT as the reference, the mutant genotype of CC + TC was significantly associated with a reduced premature CAD risk both in univariate (OR = 0.60, 95% CI = 0.41–0.87) and multivariate (OR = 0.59, 95% CI = 0.40–0.87) logistic regressions, but not with late-onset CAD risk. After excluding one article that deviated from Hardy–Weinberg equilibrium in controls, this meta-analysis showed a significant association of the C allele with reduced risk of CAD in dominant (FEM: OR = 0.69, 95% CI = 0.61–0.78), recessive (OR = 0.64, 95% CI = 0.50–0.82), and codominant (FEM: OR = 0.73, 95% CI = 0.65–0.80) models. Our study suggested that the mutant genotype of CC + TC was significantly associated with a reduced CAD risk.     

<Emphasis Type="Italic">Complement factor H</Emphasis> Y402H gene polymorphism and coronary heart disease susceptibility: a meta-analysis

The complement factor H (CFH) Y402H (T1277C) gene polymorphism has been reported to be associated with coronary heart disease (CHD), but results were conflicting. To evaluate the role of the variant in CHD, we performed meta-analyses of all available data. Both electronic and manual searches were performed, all relevant studies were identified. ORs with 95% confidential intervals (CI) under codominant (CC versus TT, TC versus TT), dominant (CC + TC versus TT) and recessive (CC versus TT + TC) models were calculated. Publication bias was addressed. Ten studies including 11 cohorts comprising of 29,764 participants were included. No association between the CFH T1227C polymorphism and CHD could be found. (For overall analysis: dominant model, OR = 1.04, 95%CI: 0.97–1.11; recessive model, OR = 1.04, 95%CI: 0.97–1.11; for Caucasian subgroup: OR = 1.08 95%CI: 0.92–1.27; recessive model, OR = 1.03, 95%CI: 0.96–1.11). Two studies reported positive results in separate population (Caucasian study: recessive model, OR = 0.51, 95%CI: 0.30–0.86; Asians study: dominant model, OR = 2.37, 95%CI: 1.13–4.96). Current evidence do not support the association between the CFH T1277C polymorphism and CHD risk among common population. The association, which could be influenced by CHD onset age, CHD risk factors status and genetics backgrounds, might be significant in some population. More studies on different CHD onset ages and risk factor status should be encouraged.