Many studies have indicated possible associations between a polymorphism of adiponectin receptor 1 (ADIPOR1) rs1342387 and risk of cancer, but contradictory results have been reported. The main aim of this study was to draw a reliable conclusion about the relationship between the rs1342387 polymorphism and cancer incidence, by conducting a literature search of Pubmed, Embase, Wanfang and Cochrane libraries. Eleven studies including 3, 738 cases and 4, 748 controls were identified in this meta-analysis. The ADIPOR1 rs1342387 polymorphism was associated with risk of colorectal cancer for all genetic comparison models (GG vs AA, OR: 1.44, 95%CI: 1.21 -1.70; G carriers vs A carriers, OR: 1.23, 95%CI: 1.11 -1.36; dominant model, OR: 1.28, 95%CI: 1.10 -1.49 and recessive model, OR: 1.31, 95%CI: 1.12 -1.55). Stratified by ethnicity, the rs1342387 polymorphism was significantly associated with risk of colorectal cancer in Asian ancestry for all genetic comparison models (GG vs AA, OR: 1.56, 95%CI: 1.26-1.92; G carriers vs. A carriers OR: 1.30, 95%CI: 1.18 -1.43; dominant model OR: 1.31, 95%CI: 1.08 -1.60 and recessive model OR: 1.44, 95%CI: 1.26 -1.64), but not in Caucasian or mixed (Caucasian mainly) groups. In summary, the ADIPOR1 rs1342387 polymorphism is significantly associated with risk of colorectal cancer among individuals of Asian ancestry.

Toll-like receptor 4 (TLR4) is a receptor of lipopolysaccharide in the signaling transduction of gastric epithelial cell. It plays a pivotal role in activation of innate immunity and pathogen recognition and thus acts as a modulator in the development and progression of gastric cancer. Growing studies explored the association of polymorphisms in TLR4 with susceptibility to gastric cancer, but the results have remained controversial and conflicting. To investigate the effect of two selected TLR4 (+896A/G and +1196C/T) polymorphisms on gastric cancer, we performed a meta-analysis.

The association between the rs6495309 polymorphism in CHRNA3 gene and lung cancer risk has been studied in Chinese by several number case-control control studies with small number of cases and controls, and these studies might be underpowered to reveal the true association. Thus we sought to investigate the association with the risk of lung cancer by performing a comprehensive meta-analysis on the polymorphism. Five case-control studies were extracted from 3 articles on the polymorphism involving 4608 lung cancer cases and 4617 controls. The results of meta-analysis showed that significant increased risk were found for the polymorphism with the risk of lung cancer in Chinese: OR = 1.47, 95%CI = 1.33-1.63, P < 0.00001 for CC + TC vs. TT; OR = 1.24, 95%CI = 1.07-1.44, P = 0.005 for CC vs. TT + TC; OR = 1.62, 95%CI = 1.32-2.00, P < 0.00001 for CC vs. TT; OR = 1.42, 95%CI = 1.26-1.61, P < 0.00001 for CT vs. TT; OR = 1.42, 95%CI = 1.26-1.61, P < 0.00001. No significant publication bias was found for the five genetic models. Our findings demonstrated that CHRNA3 gene rs6495309 polymorphism might be a risk factor for the development of lung cancer in Chinese.

Many studies evaluated the correlations of CD133 expression with the clinical outcomes in patients treated with chemoradiotherapy (CRT) but yielded controversial results. This meta-analysis was performed to identify the impacts of CD133 expression on the prognosis of cancer patients treated with CRT. Electronic databases updated up to March 2014 were searched to find relevant studies. Relevant literatures without any language restrictions were searched via electronic databases as follows: Web of Science (1945 ~ 2013), the Cochrane Library Database (Issue 12, 2013), PubMed (1966 ~ 2013), EMBASE (1980 ~ 2013), CINAHL (1982 ~ 2013), and the Chinese Biomedical Database (CBM) (1982 ~ 2013). STATA software was used for the current meta-analysis. Hazard ratios (HR) and its corresponding 95% confidence interval (95% CI) were calculated. Six studies were identified with a total of 470 cancer patients treated with CRT. The meta-analysis results showed that CD133-positive patients had poorer overall survival (OS) than that of CD133-negative patients (HR = 2.13, 95% CI = 1.20 ~ 3.07, P < 0.001). Furthermore, CD133-positive patients displayed shorter disease-free survival (DFS) than that of CD133-negative patients (HR = 1.74, 95% CI = 0.08 ~ 3.40, P = 0.039). Ethnicity-stratified analysis indicated that CD133 expression positively correlated with shorter OS among the Japanese, Chinese, and Spanish populations (all P < 0.05). In conclusion, our findings suggest that CD133 expression may be positively correlated with poorer prognosis in cancer patients treated with CRT.

Telomere biology plays a critical and complex role in the initiation and progression of cancer. Several recent studies have provided evidence that rs401681 polymorphisms in intronic region of cleft lip and palate trans-membrane 1-like (CLPTM1L) gene sequence are associated with pancreatic cancer (PC) development, but a comprehensive synopsis is not available. We performed a meta-analysis of 6 case-control studies that included 8,253 pancreatic cancer cases and 37,646 case-free controls. We assessed the strength of the association, using odds ratios (ORs) with 95 % confidence intervals (CIs). Overall, this meta-analysis showed that rs401681 allele T was associated with a significantly increased PC risk (OR = 1.17, 95 % CI = 1.12-1.22, P heterpgeneity = 0.596 and I (2) = 0). Similarly, in the subgroup analysis by ethnicity, a significantly increased risk was found among Asians (OR = 1.15, 95 % CI = 1.07-1.24, P heterpgeneity = 0.297 and I (2) = 8.0 %) and among Caucasian (OR = 1.13, 95 % CI = 1.02-1.26, P heterpgeneity = 0.385 and I (2) = 0). No publication bias was found in the present study. This meta-analysis suggests that T allele of CLPTM1L-telomerase reverse transcriptase rs401681 polymorphism is associated with an increased PC risk, especially among Chinese. Further large and well-designed studies are needed to confirm this association.

There is emerging evidence that the microRNA-146a (miR-146a) rs2910164 polymorphism might be associated with the susceptibility to colorectal cancer (CRC). However, previous published studies have failed to achieve a definitive conclusion. We aimed to address this issue in an updated meta-analysis.

To assess the association between polymorphism in the interleukin (IL)-10 promoter region of 1082 G/A and the risk of cervical cancer and/or cervical intraepithelial neoplasia (CIN), using meta-analysis.

The association between the Val158Met polymorphism in the catechol-O-methyltransferase (COMT) gene and lung cancer risk remains controversial and inconclusive. Therefore, the meta-analysis was performed to provide a quality reevaluation of the association between the COMT Val158Met polymorphism and the risk of lung cancer.

Available epidemiological studies had estimated the correlation between glutathione S-transferases P1 (GSTP1) Ile105Val polymorphism and esophageal cancer (EC) risk. However, the conclusions were controversial and inconclusive. An updated meta-analysis was conducted to explore whether GSTP1 polymorphism could be contributed to the EC risk. Ultimately, a total of 2,992 cases and 4,758 controls from 20 previous studies were included. Crude odds ratios (ORs) with 95 % confidence intervals (95 % CIs) were used to assess the strength of the associations. Pooled results suggested that GSTP1 Ile105Val polymorphism significantly increased the risk of developing EC in Caucasians under three genetic models (G vs. A, OR 1.146, 95 % CI 1.031-1.275, P = 0.012, I(2) = 30.40 %; GA vs. AA, OR 1.208, 95 % CI 1.036-1.408, P = 0.016, I(2) = 50.30 %; GG+GA vs. AA, OR 1.219, 95 % CI 1.053-1.410, P = 0.008, I(2) = 44.50 %). However, no significant correlation was found in Asians, African and mixed ethnicities analyses. Moreover, similar results were detected for any genetic model in esophageal squamous cell carcinoma and esophageal adenocarcinoma when stratifying for pathologic types. This meta-analysis provides new evidences that GSTP1 Ile105Val gene polymorphism contributes to EC susceptibility in Caucasians.

No single-nucleotide polymorphisms (SNPs) specific for aggressive prostate cancer have been identified in genome-wide association studies (GWAS).

A systematic review and a meta-analysis were carried out in order to summarize the current published studies and to evaluate LINE-1 hypomethylation in blood and other tissues as an epigenetic marker for cancer risk.

Lung cancer is the leading cause of cancer-related death around the world; the addition of chemotherapy to treatment of this disease has been shown to significantly increase progression-free survival and overall survival. Despite newer chemotherapies, it is important to personalize the care (treatment and dose) upon each single patient's susceptibility for controlling and reducing adverse side-effects, at best. The present review describes the current status of pharmacogenomics studies regarding germline DNA variants that may alter response and tolerability to chemotherapeutic agents used to treat lung cancer, including perspective studies.

Some studies have observed a lower circulating level of adiponectin in cancer patients, but whether this observation is causal remains unresolved. We therefore undertook a meta-analysis implementing Mendelian randomization to exploit the causal relevance of circulating adiponectin with cancer by using multiple polymorphisms in adiponectin encoded gene ADIPOQ as instrumental variables. Eligible articles were identified from PubMed and Embase. Data and study quality were assessed in duplicate. Total 26 articles including 31 study groups were analyzed. Overall allelic association with cancer was significant for rs822396 (odds ratio (OR) = 0.91; P = 0.045) and rs1501299 (OR = 0.89; P = 0.051), with low or moderate heterogeneity. Carriers of rs2241766 GG genotype (weighted mean difference (WMD) = 0.86; P = 0.037) or G allele (WMD = 0.68; P = 0.047) had significantly higher circulating adiponectin than the TT genotype carriers, without heterogeneity. Using rs2241766 as an instrument in Mendelian randomization analysis, an increment of 1 mg/L in circulating adiponectin was significantly associated with a 43-50% reduced risk for lung cancer, but with a 20-40% increased risk of colorectal cancer, respectively. There was no observable publication bias. Genetically elevated circulating adiponectin might confer a protective effect against lung cancer, yet a risky effect for colorectal cancer. Further validation is urgently required.

Death-associated protein kinase1 (DAPK1) is an important tumor suppressor gene. DNA methylation can inactivate genes, which has often been observed in the carcinogenesis of cervical cancer. During the past several decades, many studies have explored the association between DAPK1 promoter methylation and cervical cancer. However, many studies were limited by the small samples size and the findings were inconsistent among them. Thus, we conducted a meta-analysis to assess the association between DAPK1 promoter methylation and cervical cancer.

Difficulties persist in differentiating pancreatic ductal adenocarcinomas (PDAC) from pancreatic inflammatory masses (PIM). Auxiliary diagnostic techniques which enhance the endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) diagnostic yield have been attempted, for example, K-ras mutation analysis. We aimed to evaluate the accuracy of K-ras mutation analysis combined with EUS-FNA for the differential diagnosis of PDAC and PIM by pooling data of existing trials.

Prostate cancer (Pca) is one of the noncutaneous cancers occurring worldwide. Its high morbidity and mortality make it a concern. X-ray repair cross-complementing group 1 (XRCC1) Arg399Gln polymorphism (rs25487) has been reported to be related to Pca. However, the conclusions are controversial. In this study, PubMed, HuGENet and Chinese National Knowledge Infrastructure (CNKI) databases were combined with a comprehensive literature search. Four models including dominant (AA + AG vs. GG), recessive (AA vs. AG+GG), codominant (AA vs. AG, AA vs. GG) and per-allele analysis (A vs. G) were applied. Finally, 15 studies with 18 sets of data were included. A positive association was discovered in pooled results for recessive (odds ratio [OR]=1.202, 95% confidence interval [95% CI], 1.060-1.363, I2=46.20%), codominant (AA vs. AG; OR=1.258, 95% CI, 1.099-1.439, I2=38.50%; AA vs. GG; OR=1.283, 95% CI, 1.027-1.602, I2=51.70%) and allele analysis (OR=1.116, 95% CI, 1.001-1.244, I2=58.00%). In ethnicity subgroup analysis, these 4 models were also significant in the Asian subgroup. However, for whites, only 2 models seemed to be significant (AA vs. AG+GG: OR=1.525, 95% CI, 1.111-2.093, I2=52.60%; AA vs. AG: OR=1.678, 95% CI, 1.185-2.375, I2=30.70%). In further analysis, we regrouped the data based on race, in which pooled results and Asian subgroup were again shown to be positive. In the next analysis, expression quantitative trait loci (eQTL), linkage disequilibrium (LD), TagSNP and functional analysis were used. The results showed that the SNP was a tag and functional SNP with LD block in both Asians and whites. In summary, we suggest that XRCC1 Arg399Gln might be significantly associated with development of Pca.

Diffuse large B cell lymphoma (DLBCL) is the most common lymphoma subtype and is clinically aggressive. To identify genetic susceptibility loci for DLBCL, we conducted a meta-analysis of 3 new genome-wide association studies (GWAS) and 1 previous scan, totaling 3,857 cases and 7,666 controls of European ancestry, with additional genotyping of 9 promising SNPs in 1,359 cases and 4,557 controls. In our multi-stage analysis, five independent SNPs in four loci achieved genome-wide significance marked by rs116446171 at 6p25.3 (EXOC2; P = 2.33 × 10(-21)), rs2523607 at 6p21.33 (HLA-B; P = 2.40 × 10(-10)), rs79480871 at 2p23.3 (NCOA1; P = 4.23 × 10(-8)) and two independent SNPs, rs13255292 and rs4733601, at 8q24.21 (PVT1; P = 9.98 × 10(-13) and 3.63 × 10(-11), respectively). These data provide substantial new evidence for genetic susceptibility to this B cell malignancy and point to pathways involved in immune recognition and immune function in the pathogenesis of DLBCL.

Previous studies investigating the association between EPHX1 polymorphisms (Tyr113His and His139Arg) and cancer risk have yielded inconsistent results. This meta-analysis was performed to derive a more precise estimation of relationship between two EPHX1 polymorphisms and risk of different types of cancer.

The results from the published studies on the association between LEPR genetic polymorphisms and cancer risk are conflicting. The common LEPR Q223R genetic polymorphism has been reported to be functional and may contribute to genetic susceptibility to cancer. However, the association between LEPR Q223R genetic polymorphism and cancer risk remains inconclusive.

This meta-analysis was conducted to evaluate the association between LEPR K109R (rs1137100) genetic polymorphism and cancer risk.