Association between Type 2 Diabetes and CDKN2A/B: a meta-analysis study

Cyclin-dependent kinase inhibitor-2A/B (CDKN2A/B) has been reported as a candidate gene of type 2 diabetes (T2D) based on its chromosomal position and its important role in β-cell function and regeneration. However, studies to date have reported inconsistent findings regarding the association between T2D and CDKN2A/B. To clarify this inconsistence, we conducted a meta-analysis based on alleles and genotypes prevalence of rs10811661 and rs564398 in CDKN2A/B. The PubMed, EMBASE, and Medline databases were systematically reviewed for studies published between January, 2006, and November, 2010. A total of 35 reports were collected, among of them only 16 studies (including 24,407 cases and 33,937 controls) match the inclusion criteria and were selected for the statistical test. In the meta-analysis of published data, our results suggest that the rs10811661 T allele (OR 1.28, 95% CI 1.21–1.36, P < 1 × 10⁻⁵) and TT genotype (OR 1.32, 95% CI 1.22–1.43, P < 1 × 10⁻⁵) of CDKN2A/B were associated with type 2 diabetes respectively, but rs564398 was not (for allele only: OR 0.96, 95% CI 0.88–1.05, P = 0.35). The association between rs10811661 T allele and T2D was observed both in Asia (P < 1 × 10⁻⁴) and Europe ethnicity groups (P = 0.002). This meta-analysis yielded evidence that rs10811661 of CDKN2A/B confers risk for T2D. Larger studies with mixed ethnicity subjects are required to validate our findings.     

The HHEX rs1111875A/G gene polymorphism is associated with susceptibility to type 2 diabetes in the iranian population

The illuminating picture of genetic mechanisms underlying the development of type 2 diabetes (T2DM) includes differently accumulated genetic polymorphisms that increase the risk along with environmental factors. A number of single nucleotide polymorphisms (SNPs) are indicated to be linked with T2DM, but also conflicting results have been found. To examine the contribution of these polymorphisms in conferring susceptibility to T2DM, the association of HHEX rs1111875A/G and CDKN2A/B rs10811661C/T common gene polymorphisms with the risk of T2DM in an Iranian population was evaluated. In this study participated 140 patients and 140 controls. Genomic DNA was extracted from samples and genotyping of the polymorphisms was performed by the Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) technique. A significant association was found with the G allele (OR = 1.729, CI = 1.184–2.523, P = 0.004) and GG genotype (OR = 2.921, 95% CI = 1.789–4.771, P< 0.001) of the rs1111875A/G SNP for susceptibility to T2DM in the recessive model. Furthermore, compared with the GG genotype, individuals with the GA genotype had a lower risk to develop T2DM (OR = 0.237, 95% CI = 0.137–0.408, P< 0.001) in the additive model. In addition, an association between the polymorphism and BMI in regard to the risk of T2DM was identified. The genotype and allele frequencies of the rs10811661C/T polymorphism did not show a statistically significant association with T2DM in any genetic model. Our results show that the rs1111875A/G polymorphism is an important susceptibility polymorphism for the development of T2DM in the Iranian population. Also, these findings support that this polymorphism is a key genetic risk factor for the development of T2DM in multiple ethnic populations.

     

A genetic variant in CDKN2A/2B locus was associated with poor prognosis in patients with esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is among the leading causes of cancer related death. Despite of extensive efforts in identifying valid cancer prognostic biomarkers, only a very small number of markers have been identified. Several genetic variants in the 9p21 region have been identified that are associated with the risk of multiple cancers. Here, we explored the association of two genetic variants in the 9p21 region, CDKN2A/B, rs10811661, and rs1333049 for the first time in 273 subjects with, or without ESCC. We observed that the patients with ESCC had a higher frequency of a TT genotype for rs10811661 than individuals in the control group, and this polymorphism was also associated with tumor size. Moreover, a CC genotype for the rs1333049 polymorphism was associated with a reduced overall survival (OS) of patients with ESCC. In particular, patients with a CC (rs1333049) genotype had a significantly shorter OS (CC genotype: 34.5 ± 8.9 months vs. CG+GG: 47.7 ± 5.9 months; p value = 0.03). We have also shown the association of a novel genetic variant in CDKN2B gene with clinical outcome of patients with ESCC. Further investigations are warranted in a larger population to explore the value of emerging markers as a risk stratification marker in ESCC.     

Association of cyclin-dependent kinase inhibitor 2A/B with increased risk of developing breast cancer

There is a growing body of data reporting the association of genetic alterations in chromosome 9P21 with the risk of developing cancer. In the current study, we studied the association of a genetic variant in CDKN2A/B, rs1333049, with the risk of developing breast cancer. A total of 339 participants with and without breast cancer entered to the study. Genotyping was done by the TaqMan real-time polymerase chain reaction (RT-PCR) method and gene expression analysis was ran by RT-PCR. Our data showed that the minor allele homozygote in the total population was 10%, whereas for heterozygote was 38%. The dominant genetic model demonstrated that individuals with breast cancer had advanced TNM classification. Moreover, the logistic regression revealed that individuals who had CC/CG genotypes might have an enhanced risk of developing breast cancer when compared to the holders of GG genotype (e.g., OR = 2.8; 95% CI,1.4–5.4; p = .001), after regulated for confounders; age and body mass index. Furthermore, our analysis showed that the CDKN2A/B gene was downregulated in patients (p < .001). We showed a meaningful relationship of CDKN2A/B with the risk of breast cancer, cancer, showing the importance of studies in great sample size and several centers for studying the value of the marker as a risk classification in the management of patients with breast cancer.     

Association of caspase 8 promoter variants and haplotypes with the risk of breast cancer and its molecular profile in an Iranian population: A case-control study

Caspase 8 (CASP8) gene plays a key role in the regulation of apoptotic cell death. Expression variation in this gene has been associated with the risk of breast cancer. The aim of this study was to investigate the association of rs3834129 and rs3769821, as functional variants, and their haplotypes with molecular profile as well as the risk of breast cancer in an Iranian population. A case-control study was conducted on 812 participants including 293 breast cancer patients and 519 healthy controls. Genotyping was performed by polymerase chain reaction–based methods. Statistical analysis was performed using SPSS Ver16. The association between polymorphisms and haplotypes with the risk of breast cancer was estimated by calculating odds ratios (OR) and chi-square (χ²) tests. In comparison with ins allele (I) of rs3834129, carriers of del allele (D) showed a lower risk of breast cancer (OR, 0.65; 95% confidence interval [CI], 0.49-0.87; P = 0.004). The multivariate logistic regression model indicated DD genotype as an independent factor for a decreased risk of breast cancer in our population (OR, 0.18; 95% CI, 0.06-0.58; P = 0.004). Also, the C allele of rs3769821 was associated with a 43% increased risk of breast cancer (P = 0.005); however, after adjustment for confounding factors, no association with rs3769821 and breast cancer was observed. In addition, D-T haplotype and diplotype presented protective effects (P < 0.05). Our results indicate that genetic variations in the promoter region of CASP8 gene, especially rs3834129, may serve as a genetic risk factor for breast cancer in an Iranian population.     

The protective effects of the methylenetetrahydrofolate reductase rs1801131 variant among Saudi smokers

Methylenetetrahydrofolate reductase (MTHFR) polymorphism plays a fundamental role in susceptibility to various diseases, including cancers and autoimmune diseases. In the current study, we aimed to compare genotype and allele frequency variations of rs1801131, one of the most common variants found in the MTHFR gene, among Saudi smokers and non-smokers. We hypothesized that genetic variations of this gene are responsible for many diseases, particularly those caused by cigarette smoking (CS) such as pulmonary diseases, oral cancer and lung cancer. We performed a case-control study on a sample of 235 healthy smokers and 239 healthy non-smokers in Saudi Arabia. The rs1801131 SNP genotypes were determined using a genotyping assay and multiple in silico algorithmic software programs were used to identify the effects and structural functions of the rs1801131 (Glu429Ala) mutation. Using chi-squared tests, we found that, among smokers, TG and GG genotype carriers had 0.209-fold (OR = 0.209, P < 0.005) and 0.427-fold (OR = 0.427, P = 0.003) lower risks of CS-related disease compared to TT reference genotypes. In addition, this protective effect was observed in Saudi smokers independent of age, gender, types of smoking, duration, and average daily smoking consumption. Filling a research gap by exploring this topic in the Saudi population, the current findings indicate that genotype and allele distributions of MTHFR rs1801131 polymorphism present fundamental protective effects against the risk of CS-related disease. These findings should be verified in future studies with larger sample sizes, different ethnicities, and patients suffering from CS-related diseases, such as oral cancer and lung cancer.     

CYP1A1 rs1048943 and rs4646903 polymorphisms associated with laryngeal cancer susceptibility among Asian populations: a meta‐analysis

Many studies have investigated the association between CYP1A1 rs1048943 and rs4646903 polymorphisms and laryngeal cancer risk, but their results have been inconsistent. The PubMed and CNKI were searched for case–control studies published up to 01 July 2015. Data were extracted and pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated. In this meta‐analysis, we assessed 10 published studies involving comprising 748 laryngeal cancer cases and 1558 controls of the association between CYP1A1 rs1048943 and rs4646903 polymorphisms and laryngeal cancer risk. For CYP1A1 rs1048943 of the homozygote G/G and G allele carriers (A/G + G/G) versus A/A, the pooled ORs were 1.77 (95% CI = 1.28–2.81, P = 0.007 for heterogeneity) and 1.86 (95% CI = 1.45–2.40, P = 0.000 for heterogeneity). For CYP1A1 rs4646903 of the homozygote G/G and G allele carriers (A/G + G/G) versus A/A, the pooled ORs were 1.53 (95% CI = 1.31–2.21, P = 0.012 for heterogeneity) and 1.33(95% CI = 1.04–1.71, P = 0.029 for heterogeneity). In the stratified analysis by ethnicity, the significantly risks were found among Asians for both the G allele carriers and homozygote G/G. However, no significant associations were found in Caucasian population all genetic models. These results from the meta‐analysis suggest that CYP1A1 rs1048943 and rs4646903 polymorphisms contribute to risk of laryngeal cancer among Asian populations.     

LncRNA CDKN2BAS rs2157719 genetic variant contributes to medulloblastoma predisposition

Background

How germline single nucleotide polymorphisms are involved in the etiology of medulloblastoma remans poorly understood. We hypothesized that CCDKN2A/B rs1063192 and rs4977756 and also the long noncoding RNA (lncRNA) CDKN2BAS rs2157719 glioma susceptibility polymorphisms identified by genome‐wide association studies may contribute to medulloblastoma predisposition.

Methods

To test this hypothesis, we genotyped these genetic variants among 160 medulloblastoma patients and 443 health controls in a Chinese population. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by logistic regression.

Results

We found that only the lncRNA CDKN2BAS rs2157719 T>C genetic polymorphism was significantly associated with an increased medulloblastoma risk (C allele: OR = 1.85, 95% CI = 1.32–2.58; p = 2.7 × 10^–4). The stratified analyses showed an elevated risk of pediatric medulloblastoma associated with CDKN2BAS rs2157719 CC or TC genotype (both p < 0.05). Moreover, the association between the CDKN2BAS rs2157719 polymorphism and medulloblastoma risk is more pronounced in males (OR = 2.22, 95% CI = 1.36–3.62; p = 0.001).

Conclusions

The findings of the present study provide important insights into the genetic complexities and predisposition of medulloblastoma in Chinese, especially at the lncRNA germline variation level.     

Association of ATM and BMI‐1 genetic variation with breast cancer risk in Han Chinese

We tested the hypothesis that genetic variation in ATM and BMI‐1 genes can alter the risk of breast cancer through genotyping 6 variants among 524 breast cancer cases and 518 cancer‐free controls of Han nationality. This was an observational, hospital‐based, case–control association study. Analyses of single variant, linkage, haplotype, interaction and nomogram were performed. Risk was expressed as odds ratio (OR) and 95% confidence interval (CI). All studied variants were in the Hardy‐Weinberg equilibrium and were not linked. The mutant allele frequencies of rs1890637, rs3092856 and rs1801516 in ATM gene were significantly higher in cases than in controls (P = .005, <.001 and .001, respectively). Two variants, rs1042059 and rs201024480, in BMI‐1 gene were low penetrant, with no detectable significance. After adjustment, rs189037 and rs1801516 were significantly associated with breast cancer under the additive model (OR: 1.37 and 1.52, 95% CI: 1.10‐1.71 and 1.14‐2.04, P: .005 and .005, respectively). In haplotype analysis, haplotypes A‐C‐G‐G (in order of rs189037, rs3092856, rs1801516 and rs373759) and A‐C‐A‐A in ATM gene were significantly associated with 1.98‐fold and 6.04‐fold increased risk of breast cancer (95% CI: 1.36‐2.90 and 1.65‐22.08, respectively). Nomogram analysis estimated that the cumulative proportion of 3 significant variants in ATM gene was about 12.5%. Our findings collectively indicated that ATM gene was a candidate gene in susceptibility to breast cancer in Han Chinese.     

The association between fat mass and obesity-associated (FTO) genotype and serum vitamin D level in breast cancer patients

The preventive effect of vitamin D against breast cancer can be influenced by gene polymorphisms. This study aimed to investigate the association between serum level of 25(OH) vitamin D and FTO genotype in breast cancer patients. A cross-sectional study was carried out on 180 newly diagnosed patients with breast cancer in Tehran, Iran. The blood samples were collected from the participants in order to assess the FTO gene rs9939609 polymorphism by the tetra-primer amplification refractory mutation system (Tetra-ARMS) PCR method. The serum level of 25(OH) vitamin D was measured using the direct competitive enzyme-linked immunosorbent assay (ELISA) method. The association between vitamin D and the FTO genotype in patients with breast cancer was assessed after adjustment for cofounders. The frequency of TT, AT and AA genotypes in the breast cancer patients were 43% (n = 77), 49% (n = 89) and 8% (n = 14), respectively. All patients with higher than 40 ng/dl of serum 25(OH) vitamin D had one or two copies of FTO rs9939609 risk allele (p = 0.019). No linear association was found between the number of FTO risk allele and the level of serum vitamin D. All patients with high serum level of 25(OH) vitamin D had one or two copies of FTO rs9939609 risk allele. FTO gene polymorphisms may counteract the beneficial effects of vitamin D in breast cancer prevention. Further studies can help to better understand the genetic factors predisposing to breast cancer and their effect on the association between vitamin D and breast cancer.     

Genetic predisposition of six well‐defined polymorphisms in HMGB1/RAGE pathway to breast cancer in a large Han Chinese population

Breast cancer constitutes an enormous burden in China. A strong familial clustering of breast cancer suggests a genetic component in its carcinogenesis. To examine the genetic predisposition of high mobility group box‐1/receptor for advanced glycation end products (HMGB1/RAGE) pathway to breast cancer, we genotyped six well‐defined polymorphisms in this pathway among 524 breast cancer patients and 518 cancer‐free controls from Heilongjiang province, China. There were no deviations from Hardy–Weinberg equilibrium for all polymorphisms. In single‐locus analysis, the frequency of rs1800624 polymorphism mutant A allele in RAGE gene was significantly higher in patients than in controls (24.52% versus 19.50%, P = 0.006), with the carriers of rs1800624‐A allele being 1.51 times more likely to develop breast cancer relative to those with rs1800624‐GG genotype after adjustment (95% confidence interval or CI: 1.17–1.94, P = 0.001). In HMGB1 gene, haplotype analysis did not reveal any significance, while in RAGE gene, haplotypes C‐T‐A and C‐A‐G (alleles in order of rs1800625, rs18006024, rs2070600) were significantly associated with an increased risk of breast cancer (adjusted OR = 2.72 and 10.35; 95% CI: 1.20–6.18 and 1.58–67.80; P = 0.017 and 0.015 respectively). In further genetic score analysis, per unit and quartile increments of unfavourable alleles were significantly associated with an increased risk of breast cancer after adjustment (odds ratio or OR = 1.20 and 1.26; 95% CI: 1.09–1.32 and 1.12–1.42; P < 0.001 and <0.001 respectively). Our findings altogether demonstrate a significant association between RAGE gene rs1800624 polymorphism and breast cancer risk, and more importantly a cumulative impact of multiple risk associated polymorphisms in HMGB1/RAGE pathway on breast carcinogenesis.     

CDKN2B-AS1 gene rs4977574 A/G polymorphism and coronary heart disease: A meta-analysis of 40,979 subjects

It has been implied that there is a possible relationship between cyclin-dependent protein kinase inhibitors antisense RNA 1 (CDKN2B-AS1) gene rs4977574 A/G polymorphism and coronary heart disease (CHD) susceptibility. However, as the research results are discrepant, no distinct consensus on this issue has been reached so far. In order to further elaborate the latent association of the CDKN2B-AS1 gene rs4977574 A/G polymorphism and CHD, this present meta-analysis was conducted. There were 40,979 subjects of 17 individual studies in the present meta-analysis. The pooled odds ratios (ORs) and their corresponding 95% confidence intervals (CIs) were estimated to determine the association strength. Considering the significant heterogeneity among the individual studies, the random-effect models were used. In the current meta-analysis, a significant association between CDKN2B-AS1 gene rs4977574 A/G polymorphism and CHD was found under allelic (OR: 1.18, 95% CI: 1.08–1.29, p = 4.83×10⁻⁴), recessive (OR: 1.36, 95% CI: 1.11–1.67, p = 0.003), dominant (OR: 0.71, 95% CI: 0.58–0.86, p = 6.26×10⁻⁴), heterozygous (OR:1.210, 95% CI: 1.076–1.360, p = 0.001), homozygous (OR: 1.394, 95% CI: 1.163–1.671, p = 3.31×10⁻⁴) and additive (OR: 1.180, 95% CI: 1.075–1.295, p = 4.83×10⁻⁴) genetic models. A more significant association between them was found in the Asian population than that in the whole population under these genetic models (p < 0.05). However, no significant association between them was found in the Caucasian population (p > 0.05). CDKN2B-AS1 gene rs4977574 A/G polymorphism was associated with CHD susceptibility, especially in the Asian population. G allele of CDKN2B-AS1 gene rs4977574 A/G polymorphism is the risk allele for CHD.     

Associations of Polymorphisms in MTHFR Gene with the Risk of Age-Related Cataract in Chinese Han Population: A Genotype-Phenotype Analysis

Homocysteine (Hcy) is a potential risk factor for age-related cataract (ARC). Methylenetetrahydrofolate reductase (MTHFR) is the key enzyme for Hcy metabolism, and variants of MTHFR may affect MTHFR enzyme activity. This study mainly evaluated the associations between variants in MTHFR gene, plasma MTHFR enzyme activity, total Hcy (tHcy) levels and ARC risk in Chinese population. Four single nucleotide polymorphisms (SNPs) in MTHFR gene were genotyped using the high-resolution melting (HRM) method in 502 ARC patients (mean age, 70.2 [SD, 9.0], 46.0% male) and 890 healthy controls (mean age, 67.1 [SD, 11.1], 47.6% male). The plasma MTHFR activity, folic acid (FA), vitamins B12 and B6 levels were detected by enzyme-linked immunosorbent assays (ELISA). The plasma tHcy levels were measured by an automated enzymatic assay. After the Bonferroni correction, the minor allele T of SNP rs1801133 showed a significant association with an increased risk of overall ARC (OR = 1.26, P = 0.003). Consistent association was also found between SNP rs1801133 and cortical ARC risk (OR = 1.44, P = 0.003). Haplotype analyses revealed an adverse effect of the haplotype "C-A-T-C" (alleles in order of SNPs rs3737967, rs1801131, rs1801133 and rs9651118) on ARC risk (OR = 1.55, P = 0.003). Moreover, in a joint analysis of SNPs rs9651118 and rs1801133, subjects with two unfavorable genotypes had a 1.76-fold increased risk of ARC compared with the reference group, and a statistically significant dose-response trend (P_trend = 0.001) was also observed. Further, in healthy controls and patients with cortical ARC, the allele T of SNP rs1801133 and the increasing number of unfavorable genotypes were significantly correlated with decreased MTHFR activity as well as increased tHcy levels. However, there was no significant association between FA, vitamins B12, B6 levels and MTHFR variants. Our data indicated that variants in MTHFR gene might individually and jointly influence susceptibility to ARC by affecting MTHFR enzyme activity and tHcy levels.     

Genetic variation in tumor necrosis factor and lymphotoxin-alpha (TNF–LTA) and breast cancer risk

Tumor necrosis factor (TNF) is critical to regulation of inflammation. Genetic variation in the promoter region of TNF has been associated with expression differences, and a range of auto-immune, infectious, and oncologic diseases. We analyzed eight common single nucleotide polymorphisms (SNPs) (rs746868, rs909253, rs1799964, rs1800630, rs1800750, rs1800629, rs361525, and rs1800610) to capture most of the genetic variation in TNF in addition to SNPs in lymphotoxin-alpha (LTA), a pro-inflammatory cytokine in linkage disequilibrium with the TNF promoter region. SNPs were genotyped in a USA population-based case-control study (3,318 cases, 2,841 controls). Promising results were followed-up in an independent population-based case-control study in Poland (2,228 cases, 2,378 controls). In both studies, women carrying the variant allele of rs361525 were at elevated breast cancer risk compared to the GG genotype (per allele OR = 1.18, 95% CI 1.04–1.35; P for trend = 0.008). Other SNPs were not significantly associated with breast cancer risk. Haplotype analyses did not reveal any additional associations between TNF and breast cancer risk. Data from 5,269 cases and 4,982 controls suggested that the rs361525 A allele, located in the TNF promoter region, was associated with a modest increase in breast cancer risk. Additional studies are required to replicate these findings and to determine whether rs361525 is a causative SNP or is a marker of a causative SNP.     

Interactive effects of CDKN2B-AS1 gene polymorphism and habitual risk factors on oral cancer

Oral squamous cell carcinoma (OSCC) is a common malignant disease associated with a high mortality rate and heterogeneous disease aetiology. Cyclin dependent kinase inhibitor 2B antisense RNA 1 (CDKN2B-AS1), is a long noncoding RNA that has been shown to act as a scaffold, sponge, or signal hub to promote carcinogenesis. Here, we attempted to assess the effect of CDKN2B-AS1 single-nucleotide polymorphisms (SNPs) on the susceptibility to OSCC. Five CDKN2B-AS1 SNPs, including rs564398, rs1333048, rs1537373, rs2151280 and rs8181047, were analysed in 1060 OSCC cases and 1183 cancer-free controls. No significant association of these five SNPs with the risk of developing OSCC was detected between the case and control group. However, while examining the clinical characteristics, patients bearing at least one minor allele of rs1333048 (CA and CC) were more inclined to develop late-stage (stage III/IV, adjusted OR, 1.480; 95% CI, 1.129–1.940; p = 0.005) and large-size (greater than 2 cm in the greatest dimension, adjusted OR, 1.347; 95% CI, 1.028–1.765; p = 0.031) tumours, as compared with those homologous for the major allele (AA). Further stratification analyses demonstrated that this genetic correlation with the advanced stage of disease was observed only in habitual betel quid chewers (adjusted OR, 1.480; 95% CI, 1.076–2.035; p = 0.016) or cigarette smokers (adjusted OR, 1.531; 95% CI, 1.136–2.063; p = 0.005) but not in patients who were not exposed to these major habitual risks. These data reveal an interactive effect of CDKN2B-AS1 rs1333048 with habitual exposure to behavioural risks on the progression of oral cancer.     

Distinct Role of CD86 Polymorphisms (rs1129055, rs17281995) in Risk of Cancer: Evidence from a Meta-Analysis

Background and Purpose

Previous studies concerning the role of CD86 polymorphisms (rs1129055 and rs17281995) in cancer fail to provide compelling evidence. The aim of this study was to investigate the role of common polymorphisms in the risk of cancer by meta-analysis.

Methods

By using the search terms Cluster of Differentiation 86/CD86/B7-2/polymorphism/polymorphisms/cancer, we searched PubMed, Embase, CNKI, and Wanfang and identified four studies for rs1129055 (2137 subjects) and rs17281995 (2856 subjects) respectively. Cancer risk was estimated by odds ratio (OR) and 95% confidence interval (95% CI).

Major Findings

Overall, we observed significant reduced risk of cancer in relation to rs1129055. Compared with the individuals with AA genotype, the individuals with GG genotype appeared to have 62% decreased risk to develop cancer (GG versus AA: OR, 0.62; 95% CI, 0.49–0.79; P_het., 0.996). Similar effects were indicated in the G versus A allele model and the GG versus GA+AA genetic model (OR, 0.83; 95% CI, 0.74–0.93; P_het., 0.987; OR, 0.63; 95% CI, 0.50–0.79; P_het., 0.973). In addition, we found genotypes of rs17281995 had a major effect on overall cancer risk (CC versus GG: OR, 2.38; 95% CI, 1.43–3.95; P_het., 0.433; C versus G: OR, 1.23; 95% CI, 1.06–1.43; P_het., 0.521; CC versus GC+GG: OR, 2.38; 95% CI, 1.45–3.93; P_het., 0.443). The association was also observed in Caucasians and colorectal cancer. No obvious publication bias was detected in this meta-analysis.

Conclusions

These data reveal that rs1129055 may have protective effects on cancer risk in Asians and that rs17281995 is likely to contribute to risk of cancer, particularly colorectal cancer in Caucasians.