Poor Prognosis of Phosphatase of Regenerating Liver 3 Expression in Gastric Cancer: A Meta-Analysis

Background

Overexpression of phosphatase of regenerating liver 3 (PRL-3) has been implicated in gastric cancer (GC) metastasis. Epidemiological studies have evaluated the relationship between PRL-3 expression and prognosis in GC. However, results still remains controversial. In this study, a meta-analysis was performed to evaluate the association of PRL-3 expression with overall survival (OS) and clinicopathological characteristics.

Methods

Literature databases were searched to identify eligible studies dated until April 2013. Summary hazard ratios (HRs) or odds ratios (ORs) with 95% confidence interval (95% CI) were calculated to estimate the association.

Results

A total of 1380 GC patients from six studies were included in the meta-analysis. Overall, the combined HR estimate for OS in a random-effect model was 1.89 (95% CI = 1.38–2.60; P<0.001). Results showed that PRL-3 overexpression was significantly associated with OS, indicating that it may be a biomarker for poor prognosis of GC. Both subgroup and sensitivity analyses further identified the prognostic role of PRL-3 expression in GC patients. Moreover, PRL-3 overexpression was significantly associated with tumor stage (OR = 2.25; 95% CI = 1.63–3.12; P<0.001), depth of invasion (OR = 2.03; 95% CI = 1.38–2.98; P<0.001), vascular invasion (OR = 2.52; 95% CI = 1.79–3.56; P<0.001), lymphatic invasion (OR = 3.74; 95% CI = 2.49–5.63; P<0.001), and lymph node metastasis (OR = 4.56; 95% CI = 2.37–8.76; P<0.001). However, when age, sex, tumor size, and tumor differentiation were considered, no obvious association was observed.

Conclusions

This meta-analysis reveals significant association of PRL-3 overexpression with OS and some clinicopathological features in GC. PRL-3 may be a predicative factor of poor prognosis and aggressive tumor behavior in GC patients.     

Association between Methylenetetrahydrofolate Reductase C677T Polymorphism and Susceptibility to Cervical Cancer: A Meta-Analysis

Background

To assess the association between MTHFR polymorphism and cervical cancer risk, a meta-analysis was performed.

Methods

Based on comprehensive searches of the PubMed, Embase, and Web of Science databases, we identified outcome data from all articles estimating the association between MTHFR polymorphism and cervical cancer risk. The pooled odds ratio (OR) with 95% confidence intervals (CIs) were calculated.

Results

A total of 12 studies with 2,924 cases (331 cervical intraepithelial neoplasia (CIN) I, 742 CIN II/III, 1851 invasive cervical cancer) and 2,581 controls were identified. There was no significant association between MTHFR C677T polymorphism and CIN I risk (T vs. C, OR = 1.10, 95% CI = 0.92–1.31; TT vs. CC, OR = 1.14, 95% CI = 0.78–1.68; TT+CT vs. CC, OR = 1.22, 95% CI = 0.94–1.58; TT vs. CT+CC, OR = 0.99, 95% CI = 0.70–1.40). For the CIN II/III, lack of an association was also found (T vs. C, OR = 1.08, 95% CI = 0.95–1.23; TT vs. CC, OR = 1.15, 95% CI = 0.87–1.52; TT+CT vs. CC, OR = 1.13, 95% CI = 0.94–1.35; TT vs. CT+CC, OR = 1.07, 95% CI = 0.83–1.38). The T allele had significant association to susceptibility of invasive cervical cancer in recessive model (TT vs. CT+CC, OR = 1.23, 95% CI = 1.02–1.49). On subgroup analysis by ethnicity, similarly significant differences in T vs. C, TT vs. CC, and recessive model were found in Asians.

Conclusion

The present meta-analysis suggested that MTHFR C677T polymorphism were to substantially contribute to invasive cervical cancer in recessive model.     

Sulfotransferase SULT1A1 Arg213His Polymorphism with Cancer Risk: A Meta-Analysis of 53 Case-Control Studies

Background

The SULT1A1 Arg213His (rs9282861) polymorphism is reported to be associated with many kinds of cancer risk. However, the findings are conflicting. For better understanding this SNP site and cancer risk, we summarized available data and performed this meta-analysis.

Methods

Data were collected from the following electronic databases: PubMed, Web of Knowledge and CNKI. The association was assessed by odd ratio (OR) and the corresponding 95% confidence interval (95% CI).

Results

A total of 53 studies including 16733 cancer patients and 23334 controls based on the search criteria were analyzed. Overall, we found SULT1A1 Arg213His polymorphism can increase cancer risk under heterozygous (OR = 1.09, 95% CI = 1.01–1.18, P = 0.040), dominant (OR = 1.10, 95% CI = 1.01–1.19, P = 0.021) and allelic (OR = 1.08, 95% CI = 1.02–1.16, P = 0.015) models. In subgroup analyses, significant associations were observed in upper aero digestive tract (UADT) cancer (heterozygous model: OR = 1.62, 95% CI = 1.11–2.35, P = 0.012; dominant model: OR = 1.63, 95% CI = 1.13–2.35, P = 0.009; allelic model: OR = 1.52, 95% CI = 1.10–2.11, P = 0.012) and Indians (recessive model: OR = 1.93, 95% CI = 1.22–3.07, P = 0.005) subgroups. Hospital based study also showed marginally significant association. In the breast cancer subgroup, ethnicity and publication year revealed by meta-regression analysis and one study found by sensitivity analysis were the main sources of heterogeneity. The association between SULT1A1 Arg213His and breast cancer risk was not significant. No publication bias was detected.

Conclusions

The present meta-analysis suggests that SULT1A1 Arg213His polymorphism plays an important role in carcinogenesis, which may be a genetic factor affecting individual susceptibility to UADT cancer. SULT1A1 Arg213His didn''t show any association with breast cancer, but the possible risk in Asian population needs further investigation.     

Association between MMP-1 g.-1607dupG Polymorphism and Periodontitis Susceptibility: A Meta-Analysis

Background

Matrix metalloproteinase-1 (MMP-1) plays an important role during the destruction of periodontal tissue. Although multiple studies had focused on the association between MMP-1 g.-1607dupG and periodontitis susceptibility, the results remained inconclusive. The purpose of this meta-analysis was to explore its role in the development of periodontitis.

Methods

Retrieved studies from Pubmed, Web of Science, Medline and Google Scholar Search regarding MMP-1 g.-1607dupG and periodontitis susceptibility were included into the final analysis with definite selection and exclusion criteria. Overall and stratified analyses based on disease type, severity, ethnicity and smoking status were performed. Odds ratio (OR) and 95% confidence interval (CI) were used to evaluate the association between MMP-1 g.-1607dupG and periodontitis susceptibility, while Q test and Egger’s test were adopted respectively to assess heterogeneity among studies and publication bias.

Results

A total of 1580 periodontitis cases and 1386 controls in 11 case-control studies were included in the meta-analysis. The pooled results showed significant association between periodontitis susceptibility and MMP-1 g.-1607dupG polymorphism in homozygote (2G/2G versus 1G/1G, OR = 1.50, 95% CI = 1.02–2.20) and dominant model analysis (2G/2G+2G/1G versus 1G/1G, OR = 1.28, 95% CI = 1.04–1.57). For subgroups by type of periodontitis, increased risk of chronic periodontitis was observed on heterozygote (2G/1G versus 1G/1G, OR = 2.01, 95% CI = 1.58–2.56) and dominant model (OR = 1.27, 95% CI = 1.03–1.57). Furthermore, similar association was also detected in severe chronic periodontitis (2G/2G versus 1G/1G, OR = 2.15, 95% CI = 1.35–3.43; 2G/2G+2G/1G versus 1G/1G, OR = 1.64, 95% CI = 1.12–2.39; 2G/2G versus 2G/1G+1G/1G, OR = 1.86, 95% CI = 1.31–2.64).

Conclusions

Our meta-analysis demonstrated that MMP-1 g.-1607dupG polymorphism was associated with chronic periodontitis, especially the severity of the disease condition.     

Association between the PARP1 Val762Ala Polymorphism and Cancer Risk: Evidence from 43 Studies

Background

Poly (ADP-ribose) polymerase-1 (PARP-1) plays critical roles in the detection and repair of damaged DNA, as well as cell proliferation and death. Numerous studies have examined the associations between PARP1 Val762Ala (rs1136410 T>C) polymorphism and cancer susceptibility; nevertheless, the findings from different research groups remain controversial.

Methods

We searched literatures from MEDLINE, EMBASE and CBM pertaining to such associations, and then calculated pooled odds ratio (OR) and 95% confidence interval (CI) by using random-effects model. The false-positive report probability (FPRP) analysis was used to confirm the validity of significant findings. Moreover, potential effects of rs1136410 variants on PARP1 mRNA expression were analyzed for three ethnicities by combining data from HapMap (genotype) and SNPexp (mRNA expression).

Results

The final meta-analysis incorporated 43 studies, consisting of 17,351 cases and 22,401 controls. Overall, our results did not suggest significant associations between Ala variant (Ala/Ala or Ala/Val genotype) and cancer risk. However, further stratification analysis showed significantly increased risk for gastric cancer (Ala/Ala vs. Val/Val: OR = 1.56, 95% CI = 1.01–2.42, Ala/Val vs. Val/Val: OR = 1.34, 95% CI = 1.14–1.58, dominant model: OR = 1.41, 95% CI = 1.21–1.65 and Ala vs. Val: OR = 1.29, 95% CI = 1.07–1.55). On the contrary, decreased risk for brain tumor (Ala/Val vs. Val/Val: OR = 0.77, 95% CI = 0.68–0.87, dominant model: OR = 0.77, 95% CI = 0.68–0.87 and Ala vs. Val: OR = 0.82, 95% CI = 0.74–0.91). Additionally, we found that the Ala carriers had a significantly increased risk in all models for Asians. Our mRNA expression data provided further biological evidence to consolidate this finding.

Conclusions

Despite some limitations, this meta-analysis found evidence for an association between the PAPR1 Val762Ala and cancer susceptibility within gastric cancer, brain tumor and Asian subgroups.     

Increasing Newly Diagnosed Rate and Changing Risk Factors of HCV in Yanbian Prefecture,a High Endemic Area in China

Background

The newly diagnosed rate of HCV infection is increasing in China. However, the risk factors have not been fully identified. Here, a survey was performed in Yanbian Prefecture, a high-endemic area in China.

Methods

We identified newly diagnosed HCV infection in 2007–2011, using the local National Disease Supervision Information Management System from the Chinese Center for Disease Control and Prevention. We determined the risk factors using a case-control survey by questionnaire.

Results

Yanbian Prefecture had a rapid increase in the yearly newly diagnosed rate of HCV infection from 32.6 to 72.1/100.000 from the year 2007 to 2011. People aged 50–64 years had a high HCV infection of 43.4%, but only 0.3% of cases were reported in those aged less than 20 years. Cosmetic treatment, family history, blood transfusion, and dental treatment were independent risk factors for HCV infection. Unexpectedly, cosmetic treatments [odd ratio (OR) = 5.15, 95% confidence interval (CI) = 2.31–11.48, P = 0.00] and family history (OR = 4.68, 95% CI = 2.67–8.75, P = 0.00) showed a higher risk than the conventional risk factors of blood transfusion (OR = 4.49, 95% CI = 1.95–10.37, P = 0.001) and dental treatment (OR = 2.98, 95% CI = 1.42–6.25, P = 0.00). To further analyze the intrafamilial transmission, we found that spouses of HCV patients had an increased risk for acquiring HCV (OR = 5.75, 95% CI: 1.94–17.07), without significant association between either HCV RNA viral load (P = 0.29) or genotype (P = 0.43).

Conclusions

HCV infection was increased in Yanbian Prefecture. Cosmetic treatment was a higher risk factor than medical procedure. HCV infection had a clear family clustering phenomenon, especially between spouses.     

Methylenetetrahydrofolate Reductase (MTHFR) Polymorphisms and Susceptibility for Cervical Lesions: A Meta-Analysis

Background

The association between the methylenetetrahydrofolate reductase (MTHFR) C677T/A1298C polymorphisms and the susceptibility to cervical lesions was unclear. This study was designed to investigate their precise association using a large-scale meta-analysis.

Methods

The previous 16 studies were identified by searching PubMed, Embase and CBM databases. The crude odds ratios and their corresponding 95% confidence intervals (CIs) were used to estimate the association between the MTHFR C677T/A1298C polymorphisms and the susceptibility to the cervical lesions. The subgroup analyses were made on the following: pathological history, geographic region, ethnicity, source of controls and source of DNA for genotyping.

Results

Neither of the polymorphisms had a significant association with the susceptibility to the cervical lesions in all genetic models. Similar results were found in the subgroup analyses. No association was found between the MTHFR C677T polymorphism and the cervical lesions in the Asia or the America populations though a significant inverse association was found in the Europe population (additive model: P = 0.006, OR = 0.83, 95% CI = 0.72–0.95; CT vs. CC: P = 0.05, OR = 0.83, 95% CI = 0.69–1.00; TT vs. CC: P = 0.05, OR = 0.73, 95% CI = 0.53–1.00). Interestingly, women with the MTHFR A1298C polymorphisms had a marginally increased susceptibility to invasive cancer (ICC) when compared with no carriers but no statistically significant difference in the dominant model (P = 0.06, OR = 1.21, 95% CI = 0.99–1.49) and AC vs. AA (P = 0.09, OR = 1.21, 95% CI = 0.97–1.51).

Conclusions

The MTHFR C677T and A1298C polymorphisms may not increase the susceptibility to cervical lesions. However, the meta-analysis reveals a negative association between the MTHFR C677T polymorphisms and the cervical lesions, especially in the European populations. The marginal association between the MTHFR A1298C polymorphisms and the susceptibility to cervical cancer requires a further study.     

Association between MLH1 -93G>A Polymorphism and Risk of Colorectal Cancer

Background

The -93G>A (rs1800734) polymorphism located in the promoter of mismatch repair gene, MLH1, has been identified as a low-penetrance variant for cancer risk. Many published studies have evaluated the association between the MLH1 -93G>A polymorphism and colorectal cancer (CRC) risk. However, the results remain conflicting rather than conclusive.

Objective

The aim of this study was to assess the association between the MLH1 -93G>A polymorphism and the risk of CRC.

Methods

To derive a more precise estimation of the association, a meta-analysis of six studies (17,791 cases and 13,782 controls) was performed. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to evaluate the strength of the association. Four of these published studies were performed on subjects of known microsatellite instability (MSI) status. An additional analysis including 742 cases and 10,895 controls was used to assess the association between the MLH1 -93G>A polymorphism and the risk of MSI-CRC.

Results

The overall results indicated that the variant genotypes were associated with a significantly increased risk of CRC (AG versus GG: OR = 1.06, 95% CI = 1.01–1.11; AA/AG versus GG: OR = 1.06, 95% CI = 1.01–1.11). This increased risk was also found during stratified analysis of MSI status (AA versus GG: OR = 2.52, 95% CI = 1.94–3.28; AG versus GG: OR = 1.29, 95% CI = 1.10–1.52; AA/AG versus GG: OR = 1.45, 95% CI = 1.24–1.68; AA versus AG/GG: OR = 2.29, 95% CI = 1.78–2.96). Egger’s test did not show any evidence of publication bias.

Conclusion

Our results suggest that the MLH1 -93G>A polymorphism may contribute to individual susceptibility to CRC and act as a risk factor for MSI-CRC.     

Influence of ATP-Binding Cassette Transporter 1 R219K and M883I Polymorphisms on Development of Atherosclerosis: A Meta-Analysis of 58 Studies

Background

Numerous epidemiological studies have evaluated the associations between ATP-binding cassette transporter 1 (ABCA1) R219K (rs2230806) and M883I (rs4149313) polymorphisms and atherosclerosis (AS), but results remain controversial. The purpose of the present study is to investigate whether these two polymorphisms facilitate the susceptibility to AS using a meta-analysis.

Methods

PubMed, Embase, Web of Science, Medline, Cochrane database, Clinicaltrials.gov, Current Controlled Trials, Chinese Clinical Trial Registry, CBMdisc, CNKI, Google Scholar and Baidu Library were searched to get the genetic association studies. All statistical analyses were done with Stata 11.0.

Results

Forty-seven articles involving 58 studies were included in the final meta-analysis. For the ABCA1 R219K polymorphism, 42 studies involving 12,551 AS cases and 19,548 controls were combined showing significant association between this variant and AS risk (for K allele vs. R allele: OR = 0.77, 95% CI = 0.71–0.84, P<0.01; for K/K vs. R/R: OR = 0.60, 95% CI = 0.51–0.71, P<0.01; for K/K vs. R/K+R/R: OR = 0.69, 95% CI = 0.60–0.80, P<0.01; for K/K+R/K vs. R/R: OR = 0.74, 95% CI = 0.66–0.83, P<0.01). For the ABCA1 M883I polymorphism, 16 studies involving 4,224 AS cases and 3,462 controls were combined. There was also significant association between the variant and AS risk (for I allele vs. M allele: OR = 0.85, 95% CI = 0.77–0.95, P<0.01).

Conclusions

The present meta-analysis suggested that the ABCA1 R219K and M883I polymorphisms were associated with the susceptibility to AS. However, due to the high heterogeneity in the meta-analysis, the results should be interpreted with caution.     

GSTP1 Ile105Val Polymorphism and Prostate Cancer Risk: Evidence from a Meta-Analysis

Background

Glutathione S-transferase P1 (GSTP1) is thought to be involved in the detoxification of reactive carcinogen metabolites. Numerous epidemiological studies have evaluated the association of GSTP1 Ile105Val polymorphism with the risk of prostate cancer. However, the results remain inconclusive. To derive a more precise estimation, a meta-analysis was performed.

Methodology/Principal Findings

A comprehensive search was conducted to identify the eligible studies. We used odds ratios (ORs) with 95% confidence intervals (CIs) to assess the strength of the relationship. The overall association was not significant (Val/Val vs. Ile/Ile OR = 1.06, 95% CI = 0.90–1.25, P = 0.50; Val/Val vs. Val/Ile+Ile/Ile: OR = 1.07, 95% CI = 0.91–1.25, P = 0.44). In subgroup analyses by ethnicity and prostate cancer grade, the similar results were observed. However, in stratified analysis by clinical stage, we found a significant association with low-stage prostate cancer (Val/Val vs. Ile/Ile: OR = 2.70, 95% CI = 1.73–4.22, P<0.001; Val/Val vs. Val/Ile+Ile/Ile: OR = 2.14, 95% CI = 1.38–3.33, P = 0.001). Moreover, there was no statistically significant evidence of multiplicative interactions neither between the GSTP1 Ile105Val polymorphism and GSTM1, nor between smoking status and GSTP1 on prostate cancer risk.

Conclusions

This meta-analysis showed that GSTP1 Ile105Val polymorphism might not be significantly associated with overall prostate cancer risk. Further stratified analyses showed a significant association with low-stage prostate cancer.     

Increased Risk of Developing Digestive Tract Cancer in Subjects Carrying the PLCE1 rs2274223 A>G Polymorphism: Evidence from a Meta-Analysis

Background

To date, the association between phospholipase C epsilon 1 (PLCE1) rs2274223 A>G and risk of digestive tract cancer (DTC) remains inconclusive. To derive a more precise estimation of the association, we conducted a meta-analysis on all eligible case–control studies involving 8281 cases and 10,532 controls.

Methods

A comprehensive search was conducted to identify all eligible studies of PLCE1 rs2274223 polymorphism and digestive tract cancer risk. The pooled odds ratio (OR) and the 95% confidence interval (95% CI) were calculated using a fixed or random effect model. Heterogeneity, publication bias, and sensitivity analysis were also explored.

Results

Overall, the PLCE1 rs2274223 A>G polymorphism was associated with risk of DTC in all genetic models (GA vs. AA: OR = 1.21, 95% CI = 1.14–1.29, P<0.001; GG vs. AA: OR = 1.30, 95% CI = 1.06–1.60, P = 0.012; GG/GA vs. AA: OR = 1.20, 95% CI = 1.10–1.32, P<0.001; GG vs. GA/AA: OR = 1.21, 95% CI = 1.01–1.46, P = 0.040). The recessive model did not reach statistically significance when the P values were Bonferroni corrected to 0.0125. In the stratified analysis by cancer type, ethnicity, and source of controls, significantly increased risk was observed for esophagus cancer, Asians in three genetic models (heterozygote comparison, homozygote comparison and dominant model), population-based studies in all genetic models, and for gastric cancer in the heterozygote comparison and dominant model after Bonferroni correction. However, in the subsite of gastric cancer, no significant association was found either in cardia or non-cardia gastric cancer.

Conclusion

Our study indicated that PLCE1 rs2274223 A>G polymorphism was significantly associated with increased risk of DTC, especially among Asian populations. Due to some minor limitations, our findings should be confirmed in further studies.     

Association between the XRCC1 Polymorphisms and Thyroid Cancer Risk: A Meta-Analysis from Case-Control Studies

Background

The previous published data on the association between the X-ray repair cross-conplementation group 1 (XRCC1) polymorphisms and thyroid cancer risk remained controversial. Hence, we performed a meta-analysis on all available studies that provided 1729 cases and 3774 controls (from 11 studies) for XRCC1 Arg399Gln, 1040 cases and 2487 controls for Arg194Trp (from 7 studies), and 1432 cases and 3356 controls for Arg280His (from 8 studies).

Methodology/Principal Findings

PubMed, CNKI, and EMBASE database were searched to identify relevant studies. Overall, no significant association was found between XRCC1 Arg399Gln (recessive model: OR = 0.95, 95% CI = 0.77–1.15; dominant model: OR = 0.89, 95% CI = 0.75–1.05; homozygote model: OR = 0.92, 95% CI = 0.69–1.23; Heterozygote model: OR = 0.91, 95% CI = 0.80–1.03; additive model: OR = 0.93, 95% CI = 0.81–1.07), Arg194Trp (recessive model: OR = 1.41, 95% CI = 0.62–3.23; dominant model: OR = 1.01, 95% CI = 0.77–1.34; homozygote model: OR = 1.42, 95% CI = 0.55–3.67; Heterozygote model: OR = 1.03, 95% CI = 0.85–1.26; additive model: OR = 1.08, 95% CI = 0.81–1.42), and Arg280His (recessive model: OR = 1.08, 95% CI = 0.56–2.10; dominant model: OR = 1.01, 95% CI = 0.84–1.22; homozygote model: OR = 1.00, 95% CI = 0.51–1.96; Heterozygote model: OR = 1.04, 95% CI = 0.75–1.42; additive model: OR = 1.03, 95% CI = 0.86–1.23) and thyroid cancer risk when all the eligible studies were pooled into the meta-analysis. In the further stratified and sensitivity analyses, significant association was still not found in these three genetic polymorphisms.

Conclusions/Significance

In summary, this meta-analysis indicates that XRCC1 Arg399Gln, Arg280His, and Arg194Trp are not associated with thyroid cancer.     

Association of rs6265 and rs2030324 Polymorphisms in Brain-Derived Neurotrophic Factor Gene with Alzheimer’s Disease: A Meta-Analysis

Background

The association between polymorphisms rs6265 and rs2030324 in brain-derived neurotrophic factor (BDNF) and Alzheimer’s disease (AD) has been widely reported, but the results remain controversial.

Methods

A comprehensive search of Pubmed, Web of Science, China National Knowledge Infrastructure (CNKI), Wanfang Med Online and China Biology Medical literature database (CBM) was performed. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using fixed or random-effects models. We excluded the studies with OR>3.0 or OR<0.3 for sensitive analysis. Subgroup analysis by ethnicity, form of AD and gender was carried out. Meta-regression was conducted to explore the potential sources of between-study heterogeneity.

Results

29 articles with 7548 cases and 7334 controls concerning rs6265 and 22 articles with 5796 cases and 5706 controls concerning rs2030324 were included in this meta-analysis. The combined evidence suggested rs6265 contributing significantly to the increased risk of AD in females (codominant: fixed-effects model (FEM): OR = 1.13, 95% CI = 1.04–1.23; dominant: FEM: OR = 1.17, 95% CI = 1.05–1.31), especially for Caucasian females (codominant: FEM: OR = 1.18, 95% CI = 1.03–1.34; dominant: FEM: OR = 1.18, 95% CI = 1.01–1.37) and female late-onset Alzheimer’s disease (LOAD) patients (codominant: FEM: OR = 1.22, 95% CI = 1.05–1.41; dominant: FEM: OR = 1.23, 95% CI = 1.03–1.46). No evidence indicated an association between rs2030324 with AD in codominant (random-effects model (REM): OR = 1.06, 95% CI = 0.89–1.26) and dominant (REM: OR = 1.05, 95% CI = 0.86–1.27) models.

Conclusion

This meta-analysis suggested A allele of rs6265 might increase the risk of AD in Caucasian females and female LOAD patients. In addition, no evidence indicated an association between rs2030324 with AD. Further studies are needed to confirm these results.     

Vascular Endothelial Growth Factor Genotypes and Haplotypes Contribute to the Susceptibility of Obstructive Sleep Apnea Syndrome

Background

To investigate whether VEGF polymorphisms (-460T/C, +405G/C, and +936C/T)/haplotypes influence the susceptibility of obstructive sleep apnea (OSA).

Method

A prospective case-control study was conducted to evaluate the genetic effects of VEGF polymorphisms on the development of OSA. 150 patients and 225 healthy controls were recruited for this study and their genotypes were determined by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP). The odds ratios (OR) and 95% confidence intervals (CI) were calculated by logistic regression analysis.

Result

Our study showed that the -460C allele (C vs. T: OR = 1.95, 95% CI = 1.38–2.76) and +936T allele (T vs. C: OR = 1.48, 95% CI = 1.02–2.15) were associated with an increased OSA risk, whereas +405C allele was associated with a decreased susceptibility to OSA (C vs. G: OR = 0.61, 95% CI = 0.45–0.83). Compared with the most common haplotype CCT, CGC (OR = 2.22, 95% CI = 1.19–4.13) and TGC (OR = 3.83, 95% CI = 1.56–9.40) were associated with a significantly increased risk of OSA.

Conclusion

These observations implied that VEGF gene polymorphisms might be associated with the susceptibility to OSA. These results need to be validated by other independent studies, especially in diverse ethnic populations.     

Clinicopathologic Features of Patients with Non-Small Cell Lung Cancer Harboring the EML4-ALK Fusion Gene: A Meta-Analysis

Background

The frequencies of EML4-ALK fusion gene in non-small cell lung cancer (NSCLC) with different clinicopathologic features described by previous studies are inconsistent. The key demographic and pathologic features associated with EML4-ALK fusion gene have not been definitively established. This meta-analysis was conducted to compare the frequency of the EML4-ALK fusion gene in patients with different clinicopathologic features and to identify an enriched population of patients with NSCLC harboring EML4-ALK fusion gene.

Methods

The Pubmed and Embase databases for all studies on EML4-ALK fusion gene in NSCLC patients were searched up to July 2014. A criteria list and exclusion criteria were established to screen the studies. The frequency of the EML4-ALK fusion gene and the clinicopathologic features, including smoking status, pathologic type, gender, and EGFR status were abstracted.

Results

Seventeen articles consisting of 4511 NSCLC cases were included in this meta-analysis. A significant lower EML4-ALK fusion gene positive rate was associated with smokers (pooled OR = 0.40, 95% CI = 0.30–0.54, P<0.00001). A significantly higher EML4-ALK fusion gene positivity rate was associated with adenocarcinomas (pooled OR = 2.53, 95% CI = 1.66–3.86, P<0.0001) and female (pooled OR = 0.61, 95% CI = 0.41–0.90, P = 0.01). We found that a significantly lower EML4-ALK fusion gene positivity rate was associated with EGFR mutation (pooled OR = 0.07, 95% CI = 0.03–0.19, P<0.00001). No publication bias was observed in any meta-analysis (all P value of Egger''s test >0.05); however, because of the small sample size, no results were in the meta-analysis regarding EGFR gene status.

Conclusion

This meta-analysis revealed that the EML4-ALK fusion gene is highly correlated with a never/light smoking history, female and the pathologic type of adenocarcinoma, and is largely mutually exclusive of EGFR.     

TNF-α-308G/A Polymorphism Contributes to Obstructive Sleep Apnea Syndrome Risk: Evidence Based on 10 Case-Control Studies

Objective

The aim of our study was to investigate the association between the TNF-α-308G/A polymorphism and obstructive sleep apnea syndrome (OSAS).

Method

The Medline, Web of Science, EMBASE, Chinese National Knowledge Infrastructure (CNKI), and Cochrane Central Register of Controlled Trials were searched. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to study TNF-α-308G/A polymorphism and risk of OSAS.

Result

10 case-control studies were included in our meta-analysis. The results from our study showed that the TNF-α-308G/A polymorphism was significantly associated with risk of OSAS (A vs. G: OR = 1.67, 95% CI = 1.43–1.95). In the subgroup analysis by ethnicity, the statistical similar results were observed both in European (A vs. G: OR = 1.68, 95% CI = 1.35–2.08) and Asian population (A vs. G: OR = 2.02, 95% CI = 1.50–2.71). When stratified by age, a significantly increased risk was observed in adult carries A allele compared with G allele (OR = 1.79, 95% CI = 1.50–2.13), whereas no association was found in children (OR = 1.09, 95% CI = 0.70–1.69).

Conclusion

Our study suggested that the TNF-α- 308G/A polymorphism contributed to the susceptibility to the risk of OSAS. Additional well-designed large studies are needed to validate our findings.     

Lack of an Association between CYP11B2 C-344T Gene Polymorphism and Ischemic Stroke: A Meta-Analysis of 7,710 Subjects

Background

The association between aldosterone synthase (CYP11B2) C-344T gene polymorphism and ischemic stroke remains controversial and ambiguous. To better explain the association between CYP11B2 polymorphism and ischemic stroke risk, a meta-analysis was performed.

Methods

Based on comprehensive searches of Medline, Embase, Web of Science, CNKI and CBM databases, we identified and abstracted outcome data from all articles to evaluate the association between CYP11B2 polymorphism and ischemic stroke. The pooled odds ratios (ORs) with 95% confidence intervals (CIs) were performed in all genetic models. Fixed or random effects model was separately used depending on the heterogeneity between studies. Publication bias was tested by Begg''s funnel plot and Egger''s regression test.

Results

A total of 12 studies including 3,620 ischemic stroke cases and 4,090 controls were identified. There was no statistical evidence of association between CYP11B2 C-344T polymorphism and ischemic stroke in all genetic models (allelic model: OR = 1.19, 95% CI = 0.95–1.49; additive model: OR = 1.43, 95% CI = 0.91–2.27; dominant model: OR = 1.30, 95% CI = 0.89–1.89; and recessive model: OR = 1.24, 95% CI = 0.96–1.60). On subgroup analysis by ethnicity, similarly results were found in both Asians and non-Asians. For Asians, the combined ORs and 95% CIs were (allelic model: OR = 1.07, 95% CI = 0.87–1.32; additive model: OR = 1.15, 95% CI = 0.77–1.71; dominant model: OR = 1.13, 95% CI = 0.92–1.38; and recessive model: OR = 1.09, 95% CI = 0.84–1.40). For none-Asians, the combined ORs and 95% CIs were (allelic model: OR = 1.58, 95% CI = 0.90–2.76; additive model: OR = 2.37, 95% CI = 0.79–7.05; dominant model: OR = 1.79, 95% CI = 0.77–4.19; and recessive model: OR = 1.80, 95% CI = 0.96–3.36).

Conclusion

The present meta-analysis suggested that CYP11B2 C-344T polymorphism was unlikely contribute to ischemic stroke susceptibility.     

Prognostic Value of Carbonic Anhydrase IX Immunohistochemical Expression in Renal Cell Carcinoma: A Meta-Analysis of the Literature

Background

Carbonic anhydrase IX (CAIX) protein has been correlated with progression and survival in patients with renal cell carcinoma (RCC). The prognostic value of CAIX in RCC however, remains inconclusive according to published works. This study aimed to analyze CAIX as a biological marker to predict RCC patient prognosis.

Methods

A literature search of the PubMed and Web of Knowledge databases was performed to retrieve original studies from their inception to December of 2013. Fifteen studies, collectively including a total of 2611 patients with renal cell carcinoma, were carefully reviewed. Standard meta-analysis methods were applied to evaluate the prognostic impact of CAIX expression on patient prognosis. The hazard ratio (HR) and its 95% confidence interval (CI) were recorded for the relationship between CAIX expression and survival, and the data were analyzed using Review Manager 5.2 software and Stata software 11.0.

Results

In patients with RCC, low CAIX expression was associated with poor disease-specific survival (HR = 1.89, 95% CI: 1.20–2.98, P = 0.006), unfavorable progression-free survival (HR = 2.62, 95% CI: 1.14–6.05, P = 0.02) and worse overall survival (HR = 2.03, 95% CI: 1.28–3.21, P = 0.002). Furthermore, low CAIX expression was significantly associated with the presence of lymph node metastases (odds ratio (OR) = 0.31, 95% CI = 0.15–0.62, P = 0.0009) and distant metastases (OR = 0.66, 95% CI = 0.46–0.96, P = 0.03) and predicted a higher tumor grade (OR = 0.41, 95% CI = 0.31–0.54, P<0.00001).

Conclusions

Low CAIX expression most likely indicates poor prognosis in RCC patients. Moreover, low CAIX expression was significantly associated with unfavorable clinicopathological factors. To strengthen our findings, further well-designed prospective studies should be conducted to investigate the role of CAIX expression in RCC.     

Polymorphisms in ERCC1 and XPF Genes and Risk of Gastric Cancer in an Eastern Chinese Population

Background

Inherited functional single nucleotide polymorphisms (SNPs) in DNA repair genes may alter DNA repair capacity and thus contribute to cancer risk.

Methods

Three ERCC1 functional SNPs (rs2298881C>A, rs3212986C>A and rs11615G>A) and two XPF/ERCC4 functional SNPs (rs2276466C>G and rs6498486A>C) were genotyped for 1125 gastric adenocarcinoma cases and 1196 cancer-free controls by Taqman assays. Odds ratios (OR) and 95% confidence intervals (CI) were used to estimate risk associations, and false-positive report probabilities (FPRP) were calculated for assessing significant findings.

Results

ERCC1 rs2298881C and rs11615A variant genotypes were associated with increased gastric cancer risk (adjusted OR = 1.33, 95% CI = 1.05–1.67 for rs2298881 AC/CC and adjusted OR = 1.23, 95% CI = 1.05–1.46 for rs11615 AG/AA, compared with their common genotype AA and GG, respectively). Patients with 2–3 ERCC1 risk genotypes had significant increased risk (adjusted OR = 1.56, 95% CI = 1.27–1.93), compared with those with 0–1 ERCC1 risk genotypes, and this risk was more significantly in subgroups of never drinkers, non-gastric cardia adenocarcinoma (NGCA) and clinical stage I+II. All these risks were not observed for XPF SNPs.

Conclusions

These findings suggest that functional ERCC1 SNPs may contribute to risk of gastric cancer. Larger and well-designed studies with different ethnic populations are needed to validate our findings.