Polymorphism 17q12 rs4430796 within HNF1β is a genetic variant associated with both diabetes mellitus and prostate cancer, but findings on the correlations of rs4430796 with prostate cancer risk specifically are not in agreement, especially among diverse populations. To shed some light on the contradictory findings, therefore, we carried out a meta-analysis by pooling the odds ratios (ORs) with corresponding 95% confidence intervals (CIs) of all currently available case-control studies located within PubMed and Embase databases up to December 2012. A total of 16 studies comprising 30 datasets that collectively involved 25,535 prostate cancer patients and 25,726 controls were ultimately included in this analysis. The meta-analysis of all the studies revealed that the rs4430796 polymorphism was significantly associated with an increased risk of prostate cancer in all contrast models (ORA vs G = 1.25, 95%CI = 1.21-1.30, POR < 0.001; ORAA vs GG = 1.53, 95%CI = 1.45-1.62, POR < 0.001; ORAG vs GG = 1.24, 95%CI = 1.16-1.34, POR < 0.001; ORAA vs AG+GG = 1.36, 95%CI = 1.30-1.42, POR < 0.001; ORAA+AG vs GG = 1.37, 95%CI = 1.30-1.44, POR < 0.001). After subgroup analyses stratified by ethnicity, however, the rs4430796 polymorphism was significantly associated with prostate cancer in both Caucasians and Asians but not in African-Americans. In conclusion, our meta-analysis identified a significant association between the 17q12 rs4430796 polymorphism and prostate cancer risk, although the degree of this association and frequency of the causative allele varied among men of different races.

The phosphatidylinositol-4, 5-bisphosphate 3-kinase, catalytic subunit alpha (PIK3CA) gene is frequently mutated in breast cancer (BCa). Sex hormone receptors (HRs), including estrogen receptor (ER) and progesterone receptor (PR) play pivotal roles in BCa. In this study, we evaluated the association between PIK3CA mutations and ER/PR expression and the prognostic role of PIK3CA mutations in BCa patients, and in particular, HR-positive BCa. Thirty-two studies involving 5719 cases of BCa obtained from database searches were examined. PIK3CA gene mutations correlated significantly with ER/PR expression (p < 0.00001) and relapse-free survival (RFS) (hazard ratio [HR] 0.76, 95% confidence interval [CI] 0.59-0.98, p = 0.03) but not overall survival (OS) (HR 1.14, 95%CI 0.72-1.82, p = 0.57) in unsorted BCa patients. PIK3CA mutations were not associated with OS (HR 1.06, 95%CI 0.67-1.67, p = 0.81) or RFS (HR 0.86, 95%CI 0.53-1.40, p = 0.55) in HR-positive BCa patients. In conclusion, PIK3CA mutations were significantly related to ER/PR expression and RFS in unsorted BCa patients. However, the clinical implications of PIK3CA mutations may vary according to different mutant exons. And PIK3CA mutations alone may have limited prognostic value for HR-positive BCa patients.

Fibroblast growth factor receptor (FGFR) gene amplification has been reported in different types of cancer. We performed an up-to-date meta-analysis to further characterize the prognostic value of FGFR gene amplification in patients with cancer.

The Interleukin-10 (IL-10) gene polymorphism (-1082 A>G) has been linked to the risk of developing lymphoma, but the available results were inconsistent. To derive a more precise estimation, we performed a meta-analysis.

To identify the association between methylenetetrahydrofolate reductase (MTHFR) polymorphisms and gastric cancer (GC) susceptibility.

In recent years, mounting evidence has indicated that the CCND1 G870A gene polymorphism, which impacts the mitotic cell cycle, may influence leukemia or non-Hodgkin lymphoma risk. Unfortunately, the previous results were inconsistent. Therefore, a meta-analysis was performed to obtain a more precise estimation of any association. We conducted a search in PubMed, Embase and CNKI covering all published papers up to March, 2014. A total of 9 publications including 10 case-control studies met the inclusion criteria. Odds ratios (ORs) and their 95% confidence intervals (95%CIs) were applied to assess association. The pooled ORs showed significant association in non-Hodgkin lymphoma (comparison A vs G: OR= 1.114, 95%CI=1.053-1.179, p=0.000; homozygote comparison AA vs GG: OR=1.245, 95%CI=1.110-1.396, p=0.000; heterozygote comparison AG vs GG: OR=1.095, 95%CI=1.000-1.199, p=0.05; dominant model AA/GA vs GG: OR=1.137, 95%CI=1.043-1.239, p=0.003; and recessive model AA vs

Previous epidemiological studies have suggested a potential role of the HSPA1B±1267A/G polymorphism in risk of developing cancer. However, the results were inconsistent. Therefore, we performed this meta-analysis to summarize the possible association with cancer risk.

Several studies have suggested associations between MDM2 (mouse double minute 2 homolog) polymorphisms and leukemia risk, but they reported contradictory results. For better understanding of the effect of MDM2 T309G polymorphism on leukemia risk, we performed a meta-analysis. All eligible studies were identified through a search of PubMed, Web of Science, EMBASE, and Chinese Biomedical Literature (CBM) databases before May 2014. Assessment of associations between the MDM2 T309G polymorphism and leukemia risk was conducted by odds ratios (ORs) and 95% confidence intervals (95% CIs). Finally, a total of 11 publications covering 12 case-control studies with 2, 362 cases and 5, 562 controls concerning MDM2 T309G polymorphism with respect to leukemia were included in the meta-analysis. Significant associations were found between MDM2 T309G polymorphism and leukemia risk in four models in overall populations (G vs T: OR=1.29, 95% CI=1.11- 1.49, p=0.001; GG vs TT: OR=1.67, 95% CI=1.21-2.30, p=0.002; GG vs TG/TT: OR=1.56, 95% CI=1.21-2.00, p=0.001; GG/TG vs TT: OR=1.28, 95% CI=1.05-1.57, p=0.015). In the sub-group analysis according to ethnicity, increased leukemia risks were observed in three genetic models among Asians but not Caucasians. In conclusion, the results of our meta-analysis suggest that the MDM2 T309G polymorphism can increase the risk of leukemia, especially among Asian populations.

CD44v6 (CD44 variant exon 6) is the chief CD44 variant isoform regulating tumor invasion, progression, and metastasis. The prognostic value of CD44v6 expression in non small cell lung cancer (NSCLC) has been evaluated in many studies, but the results have remained controversial. Thus, we performed a meta- analysis of currently available studies to investigate the prognostic value of CD44v6 expression in NSCLC patients and the relationship between the expression of CD44v6 and clinicopathological features.

The rs2273535 polymorphism in the AURKA gene had proven to be associated with breast carcinoma susceptibility. Nevertheless, the results of different studies remain contradictory. A meta-analysis covering 28, 789 subjects from eleven different studies was here carried out in order to investigate the association in detail. The random effects model was used to analyze the pooled odds ratios (ORs) and their corresponding 95% confidence intervals (95% CIs). A significant relationship between the rs2273535 polymorphism and breast tumors was found in an allelic genetic model (OR: 1.076, 95% CI: 1.004-1.153, p=0.040, Pheterogeneity=0.002). No significant association was detected in a homozygote model (OR: 1.186, 95% CI: 0.990-1.423, P=0.065, Pheterogeneity=0.002), a heterozygote model (OR: 1.016, 95% CI: 0.959-1.076, p=0.064, Pheterogeneity=0.000), a dominant genetic model (OR: 1.147, 95% CI: 0.992-1.325, p=0.217, Pheterogeneity=0.294) and a recessive genetic model (OR: 1.093, 95% CI: 0.878- 1.361, p=0.425, Pheterogeneity=0.707). A significant relationship between the rs2273535 polymorphism in the AURKA gene and breast tumor in Asian group was found in an allelic genetic model (OR: 1.124, 95% CI: 1.003-1.29, p=0.044, Pheterogeneity=0.034), a homozygote model (OR: 1.229, 95% CI: 1.038-1.455, p=0.016, Pheterogeneity=0.266) and a recessive genetic model (OR: 1.227, 95% CI: 1.001-1.504, p=0.049, Pheterogeneity=0.006). A significant association was thus observed between the rs2273535 polymorphism in the AURKA gene and breast cancer risk. Individuals with the rs2273535 polymorphism in the AURKA gene have a higher risk of breast cancer in Asian populations, but not in Caucasians.

Numerous studies have explored the influence of XPD Lys751Gln and/or Asp312Asn polymorphisms on skin cancer susceptibility. However, the results remain inconclusive. To derive a more precise estimation, we conducted a comprehensive search to identify all available published studies and performed a meta-analysis.

The X-ray repair cross-complementing group 3 (XRCC3) is a highly suspected candidate gene for cancer susceptibility. Attention has been drawn upon associations of the XRCC3 Thr241Met polymorphism with breast cancer risk. However, the previous published findings remain controversial. Hence, we performed a meta-analysis to accurately evaluate any association between breast cancer and XRCC3 T241M (23, 812 cases and 25, 349 controls) in different inheritance models.

This meta-analysis was performed to investigate the relationship between methylation of the P14 and O6-methylguanine-DNA methyltransferase (MGMT) genes and the risk of hepatocellular carcinoma (HCC).

Several variants within gene-encoding endothelial isoform of nitric oxide synthase have been reported to confer prostate cancer (PCa) susceptibility and/or progression. Nevertheless, studies referring to this issue have yielded inconsistent results. In order to elucidate the involvement of these variants in prostate carcinogenesis, we have conducted a meta-analysis of previously published case-control and relevant case-only studies. Eleven studies comprising in total 3,806 cases and 4,466 controls were included in the meta-analysis which yielded evidence of association of rs2070744 (ORCC = 1.43, 95% CI 1.04-1.97; p = 0.03) and intron 4a/b variant (ORab+aa = 1.47, 95% CI 1.00-2.14; p = 0.05) with PCa risk under recessive and dominant model, respectively. Furthermore, PCa patients carrying 4a/b a allele were found to have an increased risk of cancer progression to a less differentiated form, characterized by a high Gleason score (OR = 2.29, 95% CI 1.51-3.49; p < 0.01) and to higher TNM stage (OR = 2.55, 95% CI 1.71-3.81; p < 0.01). These results support the involvement of NOS3 variants in molecular pathogenesis of PCa.

The prognostic value of epidermal growth factor receptor (EGFR) mutations in resected non-small cell lung cancer (NSCLC) remains controversial. We performed a systematic review with meta-analysis to assess its role.

The main purpose of this study was to evaluate the association between reduction in XRCC2 gene and involvement of lymph node metastasis in breast cancer. In first part of the study, meta-analysis of 14 published XRCC2 studies was performed to define the role of XRCC2 gene as diagnostic marker and in second part of the study XRCC2 gene expression was observed using real time PCR in study cohort of 100 females (50 breast cancer patients and 50 controls). A statistically significant down regulation of XRCC2 (p < 0.04) and up-regulation of ki-67 (p < 0.05) was observed in breast cancer tissues compared to non-cancerous healthy tissues. In order to explore gene-gene and gene-clinicopathological parameters relationship Spearmen correlation was performed. We observed a significantly negative correlation between XRCC2 and Ki-67 expression (r = -0.376**, p < 0.01). In case of gene-clinicopathological parameters relationship, we observed a significant correlation between XRCC2 expression and lymph node status (r = -0.521***, p < 0.002) and metastatic status (r = -0.303*, p < 0.04) of breast cancer patients. Our data suggests that deregulation of XRCC2 in breast cancer has the potential to predict lymph node metastasis and may serve as a therapeutic target for breast cancer patients at risk of metastasis.

Gastric cancer (GC) accounts for one of the highest mortality worldwide and particularly in East Asia. Many studies have reported on the potential value of microRNAs (miRNAs) detection for diagnosing GC, but their results have proven inconclusive. The present meta-analysis was conducted to assess the diagnostic value of circulating miRNAs for GC diagnosis. A literature search was carried out in databases (PubMed, Embase, Web of Science, The Cochrane Library, and CNKI) and other sources using combinations of keywords relating to GC, miRNAs, and diagnosis. The values of sensitivity, specificity, positive likelihood ratios (PLR), negative likelihood ratios (NLR), and diagnostic odds ratio (DOR) reported in individual studies were pooled using random-effects models. Potential sources of heterogeneity were assessed with subgroup and meta-regression analyses. The summary receiver operating characteristic (SROC) curve and the area under the curve (AUC) were used to assess the diagnosis accuracy of miRNAs. This meta-analysis included 1,279 patients with GC and 954 healthy controls from 20 publications. The pooled sensitivity, specificity, PLR, NLR, DOR, and AUC were 0.78 (95 % CI: 0.73-0.81), 0.80 (95 % CI: 0.76-0.84), 4.0 (95 % CI: 3.1-6.0), 0.28 (95 % CI: 0.23-0.34), 14 (95 % CI: 10-21), and 0.86 (95 % CI: 0.83-0.89), respectively. Subgroup analyses showed that early stages (I and II) GC were more easily detected than later stages and that multiple miRNAs assays were more accurate than single miRNA assays. Our meta-analysis suggests that miRNAs have a high diagnostic value for GC, especially in its early stages (I and II). In addition, multiple miRNAs assays have a better diagnosis value than single miRNA assays. In conclusion, circulating miRNAs might be used as noninvasive biomarkers for the confirmation of GC detection in Asian populations.

Recent evidence suggests that common functional polymorphisms in the hypoxia inducible factor-1α (HIF-1α) gene may play an important role in the development and progression of digestive cancer, but individually published results are inconclusive. Our meta-analysis is aimed to derive a more precise estimation of the relationships between HIF-1α gene polymorphisms and digestive cancer risk. An extensive literature search for relevant studies was conducted on Pubmed, Embase, Web of Science, Cochrane Library, and CBM databases from their inception through May 1, 2013. This meta-analysis was performed using the STATA 12.0 software. The crude odds ratios (OR) with 95% confidence interval (CI) were calculated. Eight case-control studies were included with a total of 1276 digestive cancer patients and 3392 healthy controls. Our meta-analysis revealed that the A variant of HIF-1α G1790A polymorphism might be associated with increased risk of colorectal, esophageal, gastric, and liver cancers, especially among Asian populations. However, no statistically significant associations were found between HIF-1α C1772T polymorphism and susceptibility to digestive cancer. No publication bias was detected in this meta-analysis. The current meta-analysis suggests that the HIF-1α G1790A polymorphism may increase the risk of colorectal, esophageal, gastric, and liver cancers, especially among Asian populations.

HOTAIR, a newly discovered long intergenic noncoding RNA (lincRNA), has been reported to be aberrantly expressed in many types of cancers. This meta-analysis summarizes its potential role as a biomarker in malignancy.

Previous studies demonstrated that the associations between expression level of microRNA-155 (miR-155) and clinicopathological significance of breast cancer remained inconsistent. Therefore, we performed a meta-analysis based on eligible studies to summarize the possible associations.