Association between the p53 codon 72 Arg/Pro polymorphism and hepatocellular carcinoma risk

Previous studies regarding the association of p53 codon 72 Arg/Pro polymorphism with hepatocellular carcinoma (HCC) risk have provided conflicting and inconclusive findings. Thus, a meta-analysis of all currently available publications was performed to address this issue. Eleven individual case–control studies involving a total of 2,718 cases and 3,752 controls were identified after a systematic search of the PubMed, Embase, Web of Science, and Wanfang databases. The strength of the association of p53 codon 72 Arg/Pro polymorphism with HCC risk was estimated by the pooled odds ratio (OR) with its corresponding 95 % confidence interval (95 % CI). Subgroup analyses stratified by ethnicity, source of controls, gender, hepatitis virus infection status, and family history of HCC were also conducted to assess the association. Overall, significantly increased risk of HCC was identified among carriers of the homozygous genotype ProPro (OR_{ProPro vs. ArgArg}?=?1.38 (95 % CI, 1.03–1.85), P _OR?=?0.033; OR_{ProPro vs. ArgArg + ArgPro}?=?1.28 (95 % CI, 1.03–1.59), P _OR?=?0.026). In subgroup analysis by ethnicity, the pooled results suggested that the p53 codon 72 Arg/Pro polymorphism was associated with an increased risk of HCC in Asians and Caucasians (for Asians, OR_{ProPro vs. ArgArg + ArgPro}?=?1.17 (95 % CI, 1.02–1.34), P _OR?=?0.025; for Caucasians, OR_{ProPro vs. ArgArg}?=?1.65 (95 % CI, 1.07–2.56), P _OR?=?0.025; OR_{ProPro vs. ArgArg + ArgPro}?=?1.74 (95 % CI, 1.14–2.66), P _OR?=?0.010). Subgroup analyses by source of controls and hepatitis virus infection status further demonstrated the significant association, whereas stratification factors involving gender and family history of HCC did not modify the association between p53 codon 72 Arg/Pro polymorphism and HCC risk. This meta-analysis suggests that the p53 codon 72 Arg/Pro polymorphism may play a critical role in the development of HCC, and gender and family history of HCC may not modulate the effect of p53 codon 72 Arg/Pro in HCC risk.     

P53 codon 72 polymorphism and lung cancer risk: evidence from 27,958 subjects

The role of p53 codon 72 polymorphism in the development of lung cancer remains obscure due to inconsistent findings of individual case–control studies published to date. A meta-analysis was conducted to better estimate the association between the p53 codon 72 variant and lung cancer risk. All relevant publications from the PubMed, Embase, Web of Science, and Wanfang databases were retrieved. Based on the inclusion criteria, 39 publications involving 44 independent case–control studies were finally included into this meta-analysis. Data were extracted and the pooled odds ratio (OR) with the corresponding 95 % confidence interval (95 % CI) was calculated. The overall pooled ORs showed no significant relationship of the p53 codon 72 polymorphism with increased or decreased risk of lung cancer in all gene contrast models (OR _{Pro vs. Arg}?=?1.04, 95 % CI?=?0.96–1.13, P _OR?<?0.001; OR _{Pro/Pro vs. Arg/Arg}?=?1.07, 95 % CI?=?0.91–1.25, P _OR?<?0.001; OR _{Arg/Pro vs. Arg/Arg} =1.04, 95 % CI?=?0.94–1.15, P _OR?<?0.001; OR _{Pro/Pro + Arg/Pro vs. Arg/Arg}?=?1.04, 95 % CI?=?0.94–1.16, P _OR?<?0.001; OR _{Pro/Pro vs. Arg/Arg + Arg/Pro}?=?1.07, 95 % CI?=?0.93–1.23, P _OR?<?0.001). According to the ethnicity, no significant association was observed in subgroup analyses of the Asians, Caucasians, Africans and the mixed population. Similar finding was found in subgroup analyses of hospital-based and population-based studies. Concerning the histological types of lung cancer, the p53 codon 72 variant exerts risk effect on the lung carcinogenesis in patients with adenocarcinoma (OR _{Arg/Pro vs. Arg/Arg}?=?1.10, 95 % CI?=?1.00–1.22, P _OR?=?0.048). Additionally, subgroup analysis by the smoking status demonstrated that the p53 codon 72 variant seemed to play a protective role in lung carcinogenesis among the non-smokers but not the smokers in the contrast model of Arg/Pro vs. Arg/Arg (OR _{Arg/Pro vs. Arg/Arg}?=?0.71, 95 % CI?=?0.50–1.00, P _OR?=?0.049). The present meta-analysis suggests the p53 codon 72 polymorphism may weakly modify the risk for lung cancer among the adenocarcinoma patients and non-smokers. Nevertheless, this association needs further confirmation in future studies with high quality.     

Quantitative assessment of the association between TP53 Arg72Pro polymorphism and risk of glioma

Many studies have investigated on the association between TP53 Arg72Pro polymorphism and risk of glioma, but the impact of TP53 Arg72Pro polymorphism on glioma risk is unclear owing to the obvious inconsistence among those studies. To shed light on these inconclusive findings and get a quantitative assessment of the association between the TP53 Arg72Pro polymorphism and risk of glioma, we conducted a meta-analysis of eligible studies. We searched PubMed and Embase databases for studies investigating on the association between the TP53 Arg72Pro polymorphism and risk of glioma. The pooled odds ratios (OR) with their 95 % confidence intervals (95 % CI) was calculated to assess the association between the TP53 Arg72Pro polymorphism and risk of glioma. A total of 12 studies were finally included into the meta-analysis. Meta-analysis of the 12 studies showed that TP53 Arg72Pro polymorphism was not associated with the risk of glioma (OR_{Pro vs. Arg}?=?1.07, 95 % CI 0.93～1.22; OR_{ProPro vs. ArgArg}?=?1.02, 95 % CI 0.85～1.22; OR_{ProPro/ArgPro vs. ArgArg}?=?1.06, 95 % CI 0.85～1.34; and OR_{ProPro vs. ArgArg/ArgPro}?=?1.07, 95 % CI 0.91～1.27). Subgroup analyses by ethnicity further identified that TP53 Arg72Pro polymorphism was not associated with the risk of glioma in Caucasians. However, there was a mild association between the TP53 Arg72Pro polymorphism and risk of glioma in Asians (OR_{ProPro vs. ArgArg/ArgPro}?=?1.42, 95 % CI 1.00～2.02). Thus, there is limited evidence for the association between the TP53 Arg72Pro polymorphism and risk of glioma, and more studies are needed to provide a more comprehensive assessment of the association in Asians.     

P53 codon 72 Arg/Pro polymorphism and glioma risk: an updated meta-analysis

P53 codon 72 Arg/Pro is a C/G variation upstream of the p53 gene on human chromosome 17p13. Many case–control studies have investigated the association between p53 codon 72 Arg/Pro polymorphism and glioma risk but provided inconsistent findings. To better understand the pathogenesis of glioma, we performed the current meta-analysis by pooling data from all available individual studies. According to the inclusion criteria, ten independent publications with 11 case–control studies were included into this meta-analysis. The pooled odds ratio (OR) with 95 % confidence interval (95 % CI) was calculated to estimate the effect of p53 codon 72 Arg/Pro variant on the development of glioma. Overall, no appreciable correlation was observed among the total studies in all gene models (OR_{Pro allele vs. Arg allele}?=?1.04, 95 % CI?=?0.90–1.20, P _OR?=?0.581; OR_{Pro/Pro vs. Arg/Arg}?=?0.95, 95 % CI?=?0.80–1.14, P _OR?=?0.614; OR_{Pro/Arg vs. Arg/Arg}?=?1.01, 95 % CI?=?0.79–1.29, P _OR?=?0.993; OR_{Pro/Arg + Pro/Pro vs. Arg/Arg}?=?1.03, 95 % CI?=?0.82–1.29, P _OR?=?0.799; OR_{Pro/Pro vs. Arg/Arg + Pro/Arg}?=?1.02, 95 % CI?=?0.86–1.22, P _OR?=?0.785). In stratified analyses by ethnicity, source of controls, and glioma subtypes, the p53 codon 72 Arg/Pro polymorphism did not alter the risk for glioma in population-based, hospital-based, astrocytoma, and oligodendroglioma studies among Caucasian. Interestingly, the Pro/Pro genotype seemed to be negatively associated with the glioma risk among patients with glioblastoma (OR_{Pro/Pro vs. Arg/Arg}?=?0.68, 95 % CI?=?0.48–0.95, P _OR?=?0.026). Our study suggests that the polymorphism of p53 codon 72 Arg/Pro may play a protective role in the development of glioblastoma. The relationship of p53 codon 72 Arg/Pro polymorphism with the susceptibility to glioma needs further estimation by more individual studies with high quality across ethnicities.     

Association between X-ray repair cross-complementing group 1 Arg194Trp polymorphism and colorectal cancer risk

The polymorphism of X-ray repair cross-complementing group 1 (XRCC1) Arg194Trp, a substitution of Arg to Gln at position 194, has been implicated in the development of colorectal cancer (CRC) in a number of case–control studies with contradictory and inconclusive findings. The current meta-analysis of all currently available publications was conducted to assess the gene susceptibility to CRC and improve our understanding of the CRC pathogenesis. The pooled odds ratio (OR) with corresponding 95 % confidence interval (95 % CI) was calculated by use of fixed-effects model or random-effects model when appropriate. A total of 15 eligible case–control studies with 4,501 cases and 8,038 controls were retrieved after a comprehensive search of the PubMed, Embase, Web of science, and Chinese Biomedicine (CBM) databases up to December 2012. The overall meta-analysis identified a positive but not statistically significant association between the XRCC1 Arg194Trp polymorphism and CRC risk under all genetic contrast models (OR_{Trp vs. Arg}?=?1.07, 95 % CI 0.90–1.26, P _OR?=?0.441; OR_{TrpTrp vs. ArgArg}?=?1.28, 95 % CI 0.91–1.81, P _OR?=?0.163; OR_{ArgTrp vs. ArgArg}?=?1.00, 95 % CI 0.85–1.19, P _OR?=?0.956; OR_{ArgTrp + TrpTrp vs. ArgArg}?=?1.06, 95 % CI 0.90–1.24, P _OR?=?0.502; OR_{TrpTrp vs. ArgArg + ArgTrp}?=?1.11, 95 % CI 0.91–1.34, P _OR?=?0.306). The genotype TrpTrp carriers among Caucasians were more susceptible to CRC, although lack statistical evidence (OR_{TrpTrp vs. ArgArg}?=?2.69, 95 % CI 0.97–7.49, P _OR?=?0.058; OR_{TrpTrp vs. ArgArg + ArgTrp}?=?2.77, 95 % CI 0.99–7.72, P _OR?=?0.051). Interestingly, the XRCC1 Arg194Trp variant was significantly associated with an increased risk of colon cancer. The present meta-analysis suggests that the XRCC1 Arg194Trp polymorphism may modify the risk for CRC, particularly colon cancer. However, the precise genetic association needs to be further estimated in future studies.     

No significant association between p53 codon 72 Arg/Pro polymorphism and risk of oral cancer

The genetic polymorphism of p53 codon 72 Arg/Pro has been implicated in oral cancer risk, but the results of previous studies remain controversial and ambiguous. To estimate the effect of the p53 codon 72 Arg/Pro polymorphism on the risk of oral cancer, a meta-analysis was performed. Based on a comprehensive search in PubMed, Embase, Web of Science, and China National Knowledge Infrastructure (CNKI) databases, we identified all available publications assessing the association between p53 codon 72 Arg/Pro polymorphism and oral cancer risk. The pooled odds ratio (OR) with its corresponding 95 % confidence interval (CI) was calculated to assess the association. Subgroup analyses by ethnicity and study quality were performed to further identify the correlation. Totally, 17 studies with 2,975 cases and 3,413 controls were included into this meta-analysis. There was no statistically significant association between the p53 codon 72 Arg/Pro polymorphism and oral cancer risk in all genetic contrast models (OR_{Pro allele vs. Arg allele}?=?1.05, 95 % CI 0.94–1.18, P_OR?=?0.379; OR_{Pro/Pro vs. Arg/Arg}?=?1.11, 95 % CI 0.89–1.40, P_OR?=?0.356; OR_{Pro/Arg vs. Arg/Arg}?=?1.10, 95 % CI 0.93–1.30, P_OR?=?0.256; OR_{Pro/Arg + Pro/Pro vs. Arg/Arg}?=?1.10, 95 % CI 0.93–1.31, P_OR?=?0.263; and OR_{Pro/Pro vs. Arg/Arg + Pro/Arg}?=?1.03, 95 % CI 0.90–1.18, P_OR?=?0.647). In the subgroup analysis of high-quality studies, we failed to find the susceptibility of p53 codon 72 Arg/Pro polymorphism to oral cancer. Moreover, the results were similar among Asians, Caucasians, and mixed populations when stratifying by ethnicity. Sensitivity analysis further confirmed the stability of the results. The present meta-analysis of currently available data shows no association between the p53 codon 72 Arg/Pro polymorphism and oral cancer risk.     

Association between p53 Arg72Pro polymorphism and thyroid cancer risk: a meta-analysis

The p53 is a tumor suppressor gene which may be involved in the development of thyroid cancer. Studies investigating the association between p53 Arg72Pro polymorphism and thyroid cancer risk reported conflicting results. The aim of the meta-analysis was to derive a more precise assessment of the association between p53 Arg72Pro polymorphism and thyroid cancer risk. A literature search of PubMed and Web of Science from their inception through March 2013 was conducted. Odds ratios (OR) with 95 % confidence intervals (95 % CI) were used to assess the strength of the association. Eight case–control studies were included with a total of 874 thyroid cancer cases and 1,891 controls. The meta-analysis results showed that the p53 Arg72Pro polymorphism was only associated with thyroid cancer risk under the recessive model (ProPro vs. ArgArg/ArgPro: OR?=?1.83, 95 % CI 1.05–3.20, P?=?0.034). However, there was no significant association between p53 Arg72Pro polymorphism and thyroid cancer risk under the other three genetic models (Pro vs. Arg: OR?=?1.20, 95 % CI 0.87–1.67, P?=?0.262; ProPro vs. ArgArg: OR?=?1.75, 95 % CI 0.88–3.50, P?=?0.113; ProPro/ArgPro vs. ArgArg: OR?=?1.01, 95 % CI 0.66–1.55, P?=?0.968). Subgroup by ethnicity showed that there was no significant association between p53 Arg72Pro polymorphism and thyroid cancer risk in both Caucasians and Asians. Thus, p53 Arg72Pro polymorphism may be associated with thyroid cancer risk, and ProPro genotype is likely to be a risk factor of thyroid cancer.     

Association between NAD(P)H:quinone oxidoreductase 1 rs1800566 polymorphism and risk of bladder cancer

NAD(P)H:quinone oxidoreductase 1 (NQO1) rs1800566 (Pro187Ser) is a functional polymorphism which leads to a proline-to-serine amino acid substitution at codon 187 in the NQO1 protein and enzyme activity changes. NQO1 rs1800566 polymorphism was implicated to be associated with a risk of bladder cancer, but published studies showed inconclusive results. We performed a meta-analysis of nine publications with a total of 2,661 cases and 2,738 controls on the association between NQO1 rs1800566 polymorphism and risk of bladder cancer. Data were extracted from those included studies, and the pooled odds ratio (OR) with the corresponding 95 % confidence interval (95 % CI) was calculated to assess the association. We found that there was no association between NQO1 rs1800566 polymorphism and risk of bladder cancer under all four genetic models (Ser vs. Pro, OR?=?1.06, 95 % CI?=?0.97–1.16, P?=?0.21, I ²?=?31 %; SerSer vs. ProPro, OR?=?1.12, 95 % CI?=?0.89–1.42, P?=?0.33, I ²?=?44 %; SerSer/ProSer vs. ProPro, OR?=?1.08, 95 % CI?=?0.96–1.21, P?=?0.20, I ²?=?27 %; SerSer vs. ProPro/ProSer, OR?=?1.06, 95 % CI?=?0.85–1.32, P?=?0.59, I ²?=?36 %). Meta-analysis of those eight studies from Europeans also showed that there was no association between NQO1 rs1800566 polymorphism and risk of bladder cancer under all four genetic models (Ser vs. Pro, OR?=?1.02, 95 % CI?=?0.93–1.13, P?=?0.66, I ²?=?20 %; SerSer vs. ProPro, OR?=?0.99, 95 % CI?=?0.75–1.30, P?=?0.93, I ²?=?38 %; SerSer/ProSer vs. ProPro, OR?=?1.04, 95 % CI?=?0.92–1.17, P?=?0.55, I ²?=?6 %; SerSer vs. ProPro/ProSer, OR?=?0.98, 95 % CI?=?0.75–1.28, P?=?0.87, I ²?=?39 %). This meta-analysis suggests that the NQO1 rs1800566 polymorphism is not associated with a risk of bladder cancer. Further studies with larger samples are needed, especially for studies in Asians and Africans.     

The polymorphism of EGFR 142285G > A exerts no risk effect on breast cancer

The association between the epidermal growth factor receptor (EGFR) 142285G?>?A polymorphism and the susceptibility to breast cancer is unclear. We conducted a meta-analysis of all published studies to estimate the association of EGFR 142285G?>?A polymorphism and breast cancer risk. Systematic computerized searching of the PubMed, Web of Science, and Wanfang databases was performed for relevant publications. Overall, there were three eligible case–control studies with 1,360 cases and 1,522 controls included into our study. The pooled ORs showed that the EGFR 142285G?>?A variant genotypes did not increase or decrease the risk of breast cancer under the following gene models: A vs. G, OR?=?1.07, 95 % CI 0.96–1.19, P _OR?=?0.240; AA vs. GG, OR?=?1.14, 95 % CI 0.91–1.42, P _OR?=?0.239; GA vs. GG, OR?=?0.99, 95 % CI 0.83–1.17, P _OR?=?0.892; GA?+?AA vs. GG, OR?=?1.03, 95 % CI 0.87–1.21, P _OR?=?0.727; AA vs. GG?+?GA, OR?=?1.17, 95 % CI 0.97–1.42, P _OR?=?0.096. The between-study heterogeneity was not significant among all studies. The current meta-analysis showed no evidence for significant association between EGFR 142285G?>?A polymorphism and breast cancer risk. Subsequent studies with large sample size are needed for further elucidation.     

MTHFR C677T polymorphism contributes to the risk for gastric cancer

Methylenetetrahydrofolate reductase (MTHFR) has been demonstrated to be involved in carcinogenesis. Increasing individual studies have investigated the role of MTHFR C677T polymorphism in gastric cancer pathogenesis, but with inconsistent findings. The aim of this study was to clarify the potential association of the MTHFR C677T polymorphism with gastric cancer risk by pooling all available data from published case–control studies. We searched the PubMed, Embase, Web of Science, and Wanfang databases for all relevant publications to date. The pooled odds ratio (OR) with corresponding 95 % confidence interval (95 % CI) was calculated. Stratified analysis and sensitivity analysis were also carried out to estimate the strength of this association. A total of 25 case–control studies with 6,572 cases and 9,584 controls were retrieved. Overall, the ORs under five contrast models indicated that the MTHFR C677T variant was positively associated with gastric cancer risk (OR_{T vs. C}?=?1.21, 95 % CI 1.10–1.34, P _OR?<?0.001; OR_{TT vs. CC}?=?1.47, 95 % CI 1.22–1.76, P _OR?<?0.001; OR_{TC vs. CC}?=?1.20, 95 % CI 1.03–1.40, P _OR?=?0.022; OR_{TT?+?TC vs.?CC}?=?1.27, 95 % CI 1.10–1.47, P _OR?=?0.001; OR_{TT vs.?CC?+?TC}?=?1.29, 95 % CI 1.15–1.46, P _OR?<?0.001). Stratified analyses according to ethnicity and source of controls further confirmed the significant correlations. The current meta-analysis provides strong evidence that the MTHFR C677T polymorphism may be a risk factor for gastric cancer among Asians and Caucasians.     

Association between p53 codon 72 polymorphism and sarcoma risk among Caucasians

Many published data on the association between p53 codon 72 polymorphism and sarcoma risk showed inconclusive results. The present study was designed to derive a more precise estimation of this connection among Caucasians. We conducted a literature search in PubMed, EMBASE, Web of Science, and CNKI databases for case–control studies examining the association between p53 codon 72 polymorphism and sarcoma risk. The meta-analysis was performed using STATA 12.0 software. Crude odds ratios (ORs) with corresponding 95 % confidence intervals (CIs) were used to measure the strength of any association. The results of this meta-analysis did not provide statistical evidence for significant sarcoma risk associated with p53 codon 72 polymorphism (OR_{Arg/Arg vs. Pro/Pro} = 1.00, 95 % CI = 0.80–1.26, P _{heterogeneity} = 0.980; OR_{Arg/Arg + Arg/Pro vs. Pro/Pro} = 0.99, 95 % CI = 0.83–1.19, P _{heterogeneity} = 0.990; OR_{Arg/Arg vs. Arg/Pro + Pro/Pro} = 1.09, 95 % CI = 0.89–1.35, P _{heterogeneity} = 0.532; OR_{allele Arg vs. allele Pro} = 1.03, 95 % CI = 0.90–1.18, P _{heterogeneity} = 0.883; OR_{Arg/Pro vs. Pro/Pro} = 0.95, 95 % CI = 0.71–1.27, P _{heterogeneity} = 0.919). We also did not find significant links in further subgroup analyses by ethnicity, control source, and sarcoma type. The present meta-analysis of currently available data suggests that the p53 codon 72 polymorphism may not play a role in sarcoma development in Caucasians.     

Polymorphism of 8q24 rsl3281615 and breast cancer risk

Several genome-wide association studies on breast cancer have reported similar findings of a new cancer susceptibility locus, 8q24 rsl3281615. Subsequent case–control studies have rapidly investigated the association between the single nucleotide polymorphism of rsl3281615 at chromosome 8q24 and breast cancer risk, but the effect of 8q24 rsl3281615 polymorphism on breast cancer is still unclear due to the inconsistence among those studies. Given the contradictory findings, a meta-analysis was performed to determine the association between 8q24 rsl3281615 polymorphism and breast cancer risk. 12 eligible case–control studies with a total of 42,508 cases and 53,928 controls were finally included into this meta-analysis by searching the PubMed, Embase, and China Biology Medicine (CBM) databases. We estimated the summary odds ratio (OR) with its corresponding 95 % confidence interval (95 % CI) to assess this association. Meta-analyses of total 12 studies showed 8q24 rsl3281615 polymorphism was significantly associated with an increased risk of breast cancer in all contrast models (OR_{G vs. A}?=?1.10, 95 % CI 1.05–1.14, P _OR?<?0.001; OR_{GG vs. AA}?=?1.20, 95 % CI 1.11–1.29, P _OR?<?0.001; OR_{AG vs. AA}?=?1.08, 95 % CI 1.05–1.12, P _OR?<?0.001; OR_{GG vs. AA +AG}?=?1.13, 95 % CI 1.07–1.19, P _OR?<?0.001; OR_{GG+AG vs. AA}?=?1.13, 95 % CI 1.07–1.19, P _OR?<?0.001). Meta-analyses of studies with high quality showed that 8q24 rsl3281615 polymorphism was still significantly associated with an increased risk of breast cancer under the five genetic contrast models. Sensitivity analyses by sequential omission of any individual studies and subgroup analyses by ethnicity further identified the significant association between 8q24 rsl3281615 polymorphism and breast cancer risk. Conclusively, this meta-analysis shows a significant association between 8q24 rsl3281615 polymorphism and breast cancer risk.     

HIF-1α P582S and A588T polymorphisms and digestive system cancer risk—a meta-analysis

Hypoxia-inducible factor-1 (HIF-1) influences cancer progression and metastasis through various mechanisms, and HIF-1α polymorphisms are reportedly associated with many cancers; however, the associations of HIF-1α P582S and A588T polymorphisms with the risk of digestive system cancer remain inconclusive. To understand the role of HIF-1α P582S and A588T genotypes in digestive cancer development, we conducted a comprehensive meta-analysis involving 1,517 cases and 3,740 controls. Overall, the P582S polymorphism was not significantly associated with digestive system cancers in all genotypes. By contrast, the A588T polymorphism was significantly associated with digestive system cancers in the dominant model (TT/AT vs. AA: OR?=?3.17, 95 % CI: 1.21, 8.25; P _{heterogeneity}?<?0.001). In subgroup analysis for cancer types, the two polymorphisms were only associated with increased risk of pancreatic cancer (P582S: SS vs. PP: OR?=?2.51, 95 % CI: 1.31, 4.81; SS vs. PP/PS: OR?=?8.73, 95 % CI: 1.33, 57.1; A588T: TT vs. AA: OR?=?9.30, 95 % CI: 1.12, 77.6; P _{heterogeneity}?=?0.478; TT vs. AA/AT: OR?=?3.14, 95 % CI: 1.99, 4.97; P _{heterogeneity}?=?0.098; TT/AT vs. AA: OR?=?8.65, 95 % CI: 1.05, 71.6; P _{heterogeneity}?=?0.418). According to the source of ethnicity, the P582S and the A588T polymorphisms are both significantly associated with an increased risk of cancer among Caucasians in the homozygote model (SS vs. PP: OR?=?2.41, 95 % CI: 1.24, 4.691; P _{heterogeneity}?=?0.010; TT vs. AA: OR?=?98.6, 95 % CI: 4.37, 2,224; P _{heterogeneity}?=?0.040) and the recessive model (SS vs. PP/PS: OR?=?9.48, 95 % CI: 1.12, 80.3; P _{heterogeneity}?<?0.001; TT vs. AA/AT: OR?=?82.7, 95 % CI: 3.79, 1,802; P _{heterogeneity}?=?0.041). Our findings suggest that the HIF-1α A588T polymorphism is significantly associated with higher cancer risk and the P582S polymorphism is significantly associated with pancreatic cancer risk. Furthermore, the effect of both polymorphisms on digestive system cancer is more pronounced among Caucasians than that among Asians.     

P53 codon 72 Arg/Pro polymorphism and lung cancer risk in Asians: an updated meta-analysis

The polymorphism of p53 codon 72, a transversion of G to C (Arg to Pro), has been demonstrated to be associated with the risk for lung cancer. However, individual studies conducted in Asians have provided conflicting and inconclusive findings. Thus, we performed a meta-analysis by pooling all currently available case–control studies to estimate the effect of p53 codon 72 Arg/Pro polymorphism on the development of lung cancer. The pooled odds ratios (ORs) with the corresponding 95 % confidence intervals (95 %CIs) were calculated to assess this effect. A total of 14 individual studies involving 7,929 cases and 5,924 controls were included into this meta-analysis according to the inclusion criteria. The overall OR for the dominant genetic model indicated that the p53 codon 72 Arg/Pro variant was positively correlated with lung cancer risk (OR_{Arg/Pro + Pro/Pro vs. Arg/Arg}?=?1.14, 95 %CI 1.07–1.23, P _OR?<?0.001). Similar results were found in the stratified analysis of population-based studies. The histological types of lung cancer and smoking status seemed to exert no effect on the lung cancer risk. Sensitivity analysis confirmed the stability of the above findings. The updated meta-analysis suggests that the p53 codon 72 Arg/Pro polymorphism is a risk factor for lung cancer in the Asian population. However, the potential role of gene–environment interaction in lung cancer susceptibility needs further investigation in future studies with high quality.     

Combining transarterial chemoembolization with radiofrequency ablation for hepatocellular carcinoma

The aim of this study was to compare the effectiveness of combination of radiofrequency ablation (RFA) and transarterial chemoembolization (TACE) with that of RFA alone in patients with hepatocellular carcinoma (HCC). All possible trials comparing RFA plus TACE with RFA alone for HCC were included into this meta-analysis. We estimated the summary odds ratio (OR) with its 95 % confidence interval (95 % CI) to assess the effects. Nineteen eligible studies matched the selection criteria, including 1,728 patients. Meta-analysis showed that the combination of TACE and RFA (OR_1 year?=?2.14, 95 % CI?=?1.57–2.91, P?<?0.001; OR_3 years?=?1.98, 95 % CI?=?1.28–3.07, P?=?0.001; OR_5 years?=?2.70, 95 % CI?=?1.42–5.14, P?=?0.003) were associated with higher survival rates. No evidence of publication bias was observed. High-quality evidence suggests that TACE plus RFA improve the survival rates compared with RFA alone for patients with HCC.     

Association between glutathione S-transferase T1 null genotype and risk of myelodysplastic syndromes: a comprehensive meta-analysis

Myelodysplastic syndromes (MDS) are a heterogeneous group of clonal hematologic neoplasms, and the pathophysiology of these disorders is still unclear. Previous studies investigating the association between glutathione S-transferase Tl (GSTT1) null genotype and risk of MDS reported controversial results. We performed a comprehensive meta-analysis to clarify the effect of GSTT1 null genotype on risk of MDS. The strength of the association was measured by odds ratio (OR) with 95 % confidence interval (CI). Fifteen studies were finally included, involving a total of 1,796 cases and 2,502 controls. Subgroup analysis was performed by race. Meta-analysis of all 15 studies showed that the GSTT1 null genotype was significantly associated with an increased risk of MDS (OR?=?1.47, 95 % CI 1.16–1.88, P _OR?=?0.002; I ²?=?54.4 %). Besides, an obvious association was also observed after adjusting the heterogeneity (OR?=?1.32, 95 % CI 1.13–1.54, P _OR?=?0.001; I ²?=?9.0 %). Subgroup analysis by race suggested that this association existed in both Caucasians (OR?=?1.40, 95 % CI 1.04–1.89, P _OR?=?0.027) and Asians (OR?=?1.68, 95 % CI 1.00–2.81, P _OR?=?0.049). This meta-analysis suggests the GSTT1 null genotype is significantly associated with an increased risk of MDS in both Caucasians and Asians.     

Association between the XRCC3 C241T polymorphism and lung cancer risk in the Asian population

X-ray repair cross-complementing group 3 (XRCC3) plays a vital role in maintaining the stability of genome by homologous recombination repair for DNA double-strand breaks. The genetic polymorphism of XRCC3 C241T has been implicated in lung cancer risk, but the findings across published studies in Asians are inconsistent and inconclusive. To estimate the precise association of XRCC3 C241T polymorphism with lung cancer risk, a meta-analysis of all currently available studies in Asians was performed. A comprehensive search of the PubMed, Embase, Web of Science, and China National Knowledge Infrastructure databases was conducted for eligible studies based on the inclusion criteria. The pooled odds ratios (ORs) with corresponding 95 % confidence intervals (CIs) were calculated to assess the association. Besides, subgroup analysis and sensitivity analysis were also performed for further estimation. Seven available studies with a total of 7,398 subjects were finally included into this meta-analysis. The overall ORs indicated that the XRCC3 C241T polymorphism was not associated with a lung cancer risk among Asians in all genetic contrast modes (OR_{T allele vs. C allele}?=?1.08, 95 % CI 0.95–1.24, P _OR?=?0.252; OR_{TT vs. CC}?=?1.30, 95 % CI 0.69–2.45, P _OR?=?0.426; OR_{CT vs. CC}?=?1.07, 95 % CI 0.93–1.24, P _OR?=?0.363; OR_{TT + CT vs. CC}?=?1.08, 95 % CI 0.94–1.24, P _OR?=?0.300; OR_{TT vs. CC + CT}?=?1.29, 95 % CI 0.68–2.43, P _OR?=?0.439). We failed to identify significant association between the XRCC3 C241T polymorphism and risk of lung cancer in Chinese and population-based studies. Interestingly, the pooled ORs in hospital-based studies indicated that the XRCC3 C241T variant carriers were more susceptible to lung cancer (OR_{T allele vs. C allele}?=?1.27, 95 % CI 1.04–1.56, P _OR?=?0.019; OR_{CT vs. CC}?=?1.26, 95 % CI 1.01–1.57, P _OR?=?0.045; OR_{TT + CT vs. CC}?=?1.28, 95 % CI 1.03–1.59, P _OR?=?0.027). Sensitivity analysis confirmed the stability and liability of all results. This meta-analysis suggests that the XRCC3 C241T polymorphism may not exert a risk effect on the lung cancer risk in Asians, although a statistically significant association was observed among the hospital-based studies. Thus, the precise relationship between the XRCC3 C241T variant and lung cancer risk needs further confirmation in future studies with large available data.     

Role of IL-17F T7488C polymorphism in carcinogenesis: a meta-analysis

Previous case-control studies on the association of interleukin-17F (IL-17F) T7488C polymorphism and cancer risk have yielded conflicting and inconclusive findings. We performed a meta-analysis by pooling all currently available data to acquire a more precise estimation of the association. A comprehensive literature screening from the PubMed, Embase, Web of Science, and Wanfang databases was performed for eligible publications without language restrictions. The pooled odds ratios (ORs) with corresponding 95 % confidence intervals (95 % CIs) were calculated. According to the inclusion criteria, a total of nine case-control studies with 3,034 cases and 3,694 controls were included. Overall, the pooled ORs showed that IL-17F T7488C polymorphism was associated with neither increased nor decreased risk of cancer. However, the IL-17F T7488C polymorphism exerted risk effect on cancer in population-based case-control studies when stratifying analysis by source of controls (C vs T OR?=?1.24, 95 % CI, 1.10–1.40, pooled OR (P_OR)?OR?=?0.001; CC + TC vs TT OR?=?1.29, 95 % CI, 1.12–1.48, P_OR?OR?OR?OR?相似文献   

An increased risk of ovarian cancer associated with polymorphism in BRCC5 gene in Caucasian populations

Several reports on the association between the BRCC5 gene polymorphism and ovarian cancer risk have been published recently, but the estimates of the risk vary widely. We thus performed a meta-analysis in an effort to determine the association. To identify the eligible studies, we searched the PubMed, Embase, and CNKI databases, and reviewed all original studies retrieved as well as their citations. The risk of ovarian cancer was estimated using odds ratio (OR) and its 95 % confidence interval (CI). Meta-analysis of seven comparisons revealed an obvious rise in the risk of ovarian cancer under the CC vs. GG contrast model (OR?=?1.52, 95 % CI?=?1.07–2.16, P _OR?=?0.020). A similar increase was also indicated in the CC vs. GC?+?GG model (OR?=?2.10, 95 % CI?=?1.51–2.93, P _OR?BRCC5 polymorphism may be a candidate modifier of ovarian cancer risk in Caucasians.     

Association between XRCC3 Thr241Met polymorphism and colorectal cancer risk

The x-ray repair cross-complementing group 3 (XRCC3), a member of DNA repair genes, plays a critical role in the maintenance of genome stability by homologous recombination repair for DNA double-strand breaks. The polymorphism of XRCC3 Thr241Met has been indicated to be involved in the development of some cancers, but previous individual studies on the association between XRCC3 Thr241Met polymorphism and colorectal cancer (CRC) risk have yielded conflicting and inconclusive results. To shed some light on the contradictory findings and improve our understanding of the pathogenesis of CRC, we carried out this updated meta-analysis by pooling all available publications. Databases including PubMed, Embase, Web of Science and China National Knowledge Infrastructure were searched for relevant publications. The odds ratios (ORs) with the corresponding 95 % confidence intervals (95 % CIs) were calculated to estimate the strength of the association between XRCC3 Thr241Met polymorphism and CRC risk. A total of 15 case–control studies involving 4,475 cases and 6,373 controls were included. Overall, the pooled ORs for the meta-analysis of total included studies showed no statistically significant association of XRCC3 Thr241Met polymorphism with CRC risk in any genetic model (OR_{Met allele vs. Thr allele}?=?1.17, 95 % CI 0.97–1.42, P _OR?=?0.102; OR_{MetMet vs. ThrThr}?=?1.32, 95 % CI 0.93–1.87, P _OR?=?0.121; OR_{ThrMet vs. ThrThr}?=?1.17, 95 % CI 0.94–1.45, P _OR?=?0.150; OR_{MetMet + ThrMet vs. ThrThr}?=?1.20, 95 % CI 0.96–1.51, P _OR?=?0.114; OR_{MetMet vs. ThrThr + ThrMet}?=?1.37, 95 % CI 0.98–1.93, P _OR?=?0.065). However, in subgroup analyses stratified by source of controls and ethnicity, the XRCC3 Thr241Met polymorphism was associated with an elevated risk of CRC in the hospital-based case–control studies and the Asian population. Sensitivity analysis indicated that the findings were unlikely due to chance. This meta-analysis suggests that the XRCC3 Thr241Met polymorphism may modify the risk of CRC, particularly in Asians.