Cyclin D1 G870A polymorphism and lung cancer risk: a meta-analysis

Many studies have investigated the association between Cyclin D1 (CCND1) G870A polymorphism and lung cancer risk, but the impact of CCND G870A polymorphism on lung cancer is unclear owing to the obvious inconsistence among those studies. This study aimed to quantify the strength of association between CCND1 G870A polymorphism and lung cancer risk. We searched the PubMed, Embase, and Wangfang databases for articles on studies relating the CCND1 G870A polymorphism to the risk of lung cancer in humans. We estimated summary odds ratios (ORs) with their confidence intervals (CIs) to assess the association. Meta-analyses of total studies showed that CCND1 G870A polymorphism was associated with lung cancer risk under three genetic models (OR_{A versus G}?=?1.13, 95?% CI 1.03?C1.24; OR_{AA versus GG}?=?1.20, 95?% CI 1.07?C1.35; OR_{AA versus AG + GG}?=?1.23, 95?% CI 1.02?C1.50). Meta-analyses of studies with high quality showed that CCND1 G870A polymorphism was associated with lung cancer risk under two genetic models (OR_{A versus G}?=?1.08, 95?% CI 1.02?C1.15; OR_{AA versus GG}?=?1.17, 95?% CI 1.04?C1.32). Subgroup analyses by ethnicity and sensitivity analyses further identified the significant association above. No evidence of publication bias was observed. Meta-analyses of available data show a significant association between the CCND1 G870A polymorphism and lung cancer risk, and CCND1 G870A polymorphic variant A contributes to increased risk of lung cancer.     

细胞周期蛋白D1基因G870A 多态性与结直肠癌易感性的系统评价

 目的 综合评价细胞周期蛋白D1(Cyclin D1) 基因G870A多态性与结直肠癌易感性的关系.方法通过CNKI、PubMed、EMCC等数据库检索文献,获得有关Cyclin D1基因G870A多态性与结直肠癌危险性关系的研究结果,并通过Meta分析进行系统评价。所有文献均采用病例对照研究或者巢式病例对照研究,以OR值为效应指标, 基因型在对照群体中的分布均符合Hardy Weinberg 遗传平衡定律,对文献进行评价筛选、异质性检验。本次Meta分析共纳入23项研究,累计病例6 344例,对照9 018例,利用RevMan5.0对各研究原始结果进行统计处理, 对突变纯合子AA 和杂合子GA 基因型与纯合基因型GG 进行比较,并计算合并OR值及其95%可信区间(CI）。结果 AA和GA与GG基因型在病例组与健康对照组之间差异有统计学意义,OR= 1.10（95%CI：1.01～1.19, P=0.02）;按不同人群进行分层分析,亚洲人群OR= 1.11（95%CI：0.98～1.26, P=0.11）,美洲人群OR= 1.13（95%CI：0.97~1.32,P=0.12),欧洲人群OR= 1.06（95%CI：0.89～1.25, P=0.52）,大洋洲人群OR= 1.05（95%CI：0.80～1.38, P=0.73）;按不同对照进行分组分析,医院基础OR= 1.07（95%CI：0.95～1.20, P=0.28）,人群基础OR= 1.13（95%CI：1.01~1.26, P=0.04）。结论 Cyclin D1基因G870A 多态性与结直肠癌易感性总体分析在统计学上具有相关性,按不同人群进行分组分析,都不支持具有相关性;按不同对照进行分组分析,以医院基础不具有相关性,以人群为基础具有相关性。     

Cyclin D1 A870G polymorphism and the risk of colorectal cancer and adenoma

Cyclin D1 (CCND1) plays a key role in cell cycle control, particularly in the transition from G1 to S phase, which is regulated by cyclin-dependent kinases. A common adenine to guanine polymorphism (A870G) in the CCND1 gene has been associated with a longer-life protein and an increased risk of colorectal cancer and adenoma in some studies. Among subjects with hereditary nonpolyposis colorectal cancer, the A870G polymorphism has also been associated with a younger age of onset of colorectal cancer. We analysed 181 colorectal cancer cases and 475 matched controls and 524 adenoma cases and 517 matched controls within women in the Nurses' Health Study (NHS) cohort, 171 colorectal cancer cases and 347 matched controls and 372 adenoma cases and 712 matched controls nested within men in the Health Professionals' Follow-Up Study (HPFS) cohort, and 258 colorectal cancer cases and 415 matched controls within men in the Physicians' Health Study (PHS) cohort to assess the risk associated with the CCND1 A870G genotype. Moreover, we assessed whether CCND1 genotype modified the effect of a sporadic (nonsyndromic) family history of colorectal cancer as well as the effect of other dietary and lifestyle risk factors for colorectal cancer and adenoma. In all cohorts combined, the CCND1 polymorphism did not show statistically significant associations to risk of colorectal cancer (odds ratio (OR) for A allele carriers, 1.04; 95% confidence interval (95% CI), 0.82-1.32) or adenoma (OR, 0.96; 95% CI, 0.79-1.18). The CCND1 A870G genotype was associated with a modest, although nonsignificantly elevated risk of colorectal cancer (OR, 1.59; 95% CI, 0.98-2.57) in women. In contrast, the polymorphism was not associated with increased risk of adenoma in either men or women. Among participants with the A870G genotype, a family history of colorectal cancer conferred a substantially greater risk of colorectal cancer in the women (P for interaction=0.06) and adenoma in the men (P for interaction=0.02). Current postmenopausal hormone (PMH) use was associated with a significant reduction in the risk of colorectal cancer and adenoma among women with the A870G genotype, whereas there was no effect of PMH use among those with the GG genotype. The CCND1 polymorphism appeared to confer a modest elevation in the risk of colorectal cancer among women. Moreover, the A870G genotype may enhance the protective effect of postmenopausal oestrogen use on the development of colorectal neoplasia.     

Methionine synthase A2756G polymorphism and breast cancer risk: a meta-analysis involving 18,953 subjects

The A2756G polymorphism in the methionine synthase (MTR) gene has been implicated in breast cancer risk. However, the published findings are inconsistent. We therefore performed a meta-analysis to investigate this relationship. Eleven published case–control studies, including 8,438 breast cancer cases and 10,515 controls were identified. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the strength of the association. Overall, no significant associations between the MTR A2756G polymorphism and breast cancer risk were found for GG versus AA (OR = 0.98, 95% CI: 0.84–1.15), AG versus AA (OR = 0.95, 95% CI: 0.89–1.01), GG/AG versus AA (OR = 0.95, 95% CI = 0.89–1.01), and GG versus AG/AA (OR = 1.00, 95% CI: 0.86–1.17). However, in the stratified analysis, significantly decreased breast cancer risks were found among Europeans (AG versus AA, OR = 0.90, 95% CI = 0.83–0.98; GG/AG versus AA, OR = 0.90, 95% CI = 0.82–0.97) and studies with population-based controls (AG versus AA, OR = 0.93, 95% CI = 0.86–1.00; GG/AG versus AA, OR = 0.93, 95% CI = 0.86–1.00). When stratifying by the menopausal status, no significant result was observed in all genetic models. Taken together, the results suggest that the MTR A2756G polymorphism may contribute to susceptibility to breast cancer among Europeans.     

Cyclin D1 polymorphism (G870A) and risk for esophageal adenocarcinoma

BACKGROUND: To investigate individual susceptibility to gastroesophageal reflux disease, Barrett esophagus, and esophageal adenocarcinoma, the authors studied the frequency of the common G870A polymorphism of CCND1, which encodes cyclin D1, a key cell cycle regulatory protein. METHODS: The study population included 307 patients who were enrolled in a prospective case-control study to evaluate lifestyle risk factors and molecular alterations in gastroesophageal reflux disease (n = 126 patients), Barrett esophagus (n = 125 patients), and esophageal adenocarcinoma (n = 56 patients). A control group included 95 strictly asymptomatic individuals. Genomic DNA was extracted from cases and controls, and polymerase chain reaction was used to amplify exon 4 of CCND1. After digestion with BsrI, acrylamide gel electrophoresis was used to identify the wild type and common G870A polymorphic alleles. The frequency of alleles (G/G, G/A, A/A) was compared between cases and controls. Immunohistochemistry was used to study cyclin D1 distribution in among patients in the case group. RESULTS: Compared with the asymptomatic control group, and adjusted for age and gender, increasing frequencies were seen for the A/A genotype in patients with gastroesophageal reflux disease (odds ratio [OR], 2.83; 95% confidence interval [95% CI], 1.09-7.34), Barrett esophagus (OR, 3.69; 95% CI, 1.46-9.29), and esophageal adenocarcinoma (OR, 5.99; 95% CI, 1.86-18.96). No association was seen between genotype and cyclin D1 overexpression. CONCLUSIONS: The CCND1 A/A genotype was associated with increased risk for gastroesophageal reflux disease, Barrett esophagus, and esophageal adenocarcinoma. The contribution of this polymorphism to susceptibility of defined stages of progression to esophageal adenocarcinoma suggested potential application in endoscopic Barrett surveillance programs.     

Association between the G870A polymorphism of Cyclin D1 gene and glioma risk

Previous studies have shown the association of the Cyclin D1 (CCND1) G870A polymorphism with glioma risk, but the findings are inconsistent and inconclusive. To shed some light on the findings across individual studies and acquire a quantitative assessment of this association, we conducted a meta-analysis of all published case–control studies thus far. Four independent studies with a total of 690 cases and 1,014 controls were identified after a systematic search of the PubMed, Embase, Web of Science, and Wanfang databases. The strength of the association between the CCND1 G870A polymorphism and glioma risk was estimated by the pooled odds ratios (ORs) with 95 % confidence intervals (95 %CIs). Subgroup analysis by ethnicity was also performed. Overall, a statistically significant association was found between the CCND1 G870A polymorphism and glioma risk in three genetic models (OR_{A vs. G}?=?1.178, 95 %CI 1.025–1.354, P _OR?=?0.021; OR_{AA vs. GG}?=?1.328, 95 %CI 1.007–1.750, P _OR?=?0.045; OR_{AA?+?AG vs. GG}?=?1.253, 95 %CI 1.006–1.516, P _OR?=?0.044). In subgroup analysis, the pooled ORs suggested that the CCND1 G870A polymorphism was associated with an increased risk of glioma in Caucasians under the heterozygote and dominant genetic models (OR_{AG vs. GG}?=?1.329, 95 %CI 1.001–1.766, P _OR?=?0.049; OR_{AA?+?AG vs. GG}?=?1.332, 95 %CI 1.019–1.740, P _OR?=?0.036). The meta-analysis suggests that the CCND1 G870A polymorphism is a risk factor for the development of glioma.     

CCND1 G870A polymorphism and risk for head and neck cancer: a meta-analysis

CCND1 plays a critical role in cell cycle control and may contribute to head and neck cancer. We performed a meta-analysis of eleven case–control studies that examined the association between CCND1 G870A polymorphism and head and neck cancer risk. Overall, no significant association of this polymorphism with head and neck cancer was found (for AA vs. GG: OR = 0.96, 95% CI = 0.59–1.58, P < 0.01 for heterogeneity; for GA vs. GG: OR = 1.00, 95% CI = 0.74–1.35, P < 0.01 for heterogeneity; for the dominant model GA/AA vs. GG: OR = 0.98, 95% CI = 0.69–1.39, P < 0.01 for heterogeneity; for the recessive model AA vs. GG/GA: OR = 0.94, 95% CI = 0.66–1.33, P < 0.01 for heterogeneity). In subgroup analysis by ethnicity, we also did not find any significant association in European and Asians populations. All the results were not materially altered in any genetic model after the studies which did not fulfill Hardy–Weinberg equilibrium were excluded. In conclusion, our meta-analysis strongly suggested that the CCND1 G870A polymorphism is not associated with head and neck cancer risk.     

The cyclin D1 (CCND1) G870A polymorphism and lung cancer susceptibility: a meta-analysis

Several studies have investigated the association between Cyclin D1 (CCND1) G870A genetic polymorphism and lung cancer susceptibility, but the results were inconclusive. The aim of this meta-analysis was to summarize available evidence for such a relationship. The reviewers made use of MEDLINE, EMBASE, and BIOSIS databases. The relevant data were independently extracted by two reviewers. The odds ratio (OR) with 95 % confidence interval (CI) was selected as the principal outcome measure. The heterogeneity test, the publication bias test, and the sensitivity analysis were performed. Overall, a total of 10 case–control studies were included. Our meta-analysis indicated that CCND1 G870A genetic polymorphism was a risk factor for lung cancer under homozygote model (OR?=?1.18; 95 % CI?=?1.02, 1.37), recessive model (OR?=?1.21; 95 % CI?=?1.03, 1.41), and allele model (OR?=?1.11; 95 % CI?=?1.02, 1.21). In the subgroup analysis by source of ethnicity, a statistical increase of lung cancer risk was found among Asian groups for allele model (OR?=?1.11; 95 % CI?=?1.01–1.22). The present meta-analysis suggests that CCND1 G870A polymorphism may be a risk factor for lung cancer. Besides, allele A may contribute to increased lung cancer risk.     

TGF-β1 29T/C polymorphism and breast cancer risk: a meta-analysis involving 25,996 subjects

Transforming growth factor β1 (TGF-β1) is a cytokine, playing an important role in controlling cell proliferation and differentiation involved in breast cancer. It was reported the 29T/C polymorphism in TGF-β1 has been implicated in breast cancer risk. However, studies on the association between this polymorphism and breast cancer remain conflicting. To derive a more precise estimation of the relationship, a meta-analysis of 10,341 cases and 15,655 controls from fifty published case-control studies was performed. Our analysis suggested that 29T/C has no association with a trend of breast cancer risk when using both dominant [odds ratio (OR) = 1.01, 95% confidence intervals (CI) 0.96–1.07] and recessive models (OR = 0.98, 95% CI 0.89–1.08) to analyze the data. In ethnic subgroups analysis, 29T/C also did not appear to be risk factors for breast cancer. However, larger scale primary studies are required to further evaluate the interaction of TGF-β1 29T/C polymorphism and breast cancer risk in specific populations.     

Glutathione S-transferase P1 Ile105Val polymorphism and breast cancer risk: a meta-analysis involving 34,658 subjects

Glutathione S-transferase P1 (GSTP1) is involved in a wide range of detoxifying reactions. Any alteration in the structure, function, or expression of GSTP1 gene may alter the ability of a cell to inactivate carcinogens or mutagens, and thus modify an individual’s risk to cancer. Previous epidemiological studies on the potential association between GSTP1 Ile105Val polymorphism and breast cancer risk have produced inconsistent results. In order to drive a more precise estimation of this association, we performed a meta-analysis of 30 published case–control studies including 15,901 cases and 18,757 controls. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of the association. The results of this meta-analysis showed that GSTP1 Ile105Val polymorphism was not associated with breast cancer susceptibility in overall population. However, in subgroup analysis by ethnicity, we found a significant association among Asian population (for Val/Val vs. Ile/Ile: OR 1.27, 95% CI 1.02–1.83; for the recessive model Val/Val vs. Ile/Ile + Ile/Val: OR 1.42, 95% CI 1.20–1.69). When stratified by study design, significantly elevated susceptibility to breast cancer was found among hospital-based studies (for Val/Val vs. Ile/Ile: OR 1.38, 95% CI 1.16–1.63; for recessive model Val/Val vs. Ile/Val + Ile/Ile: OR 1.31, 95% CI 1.12–1.55; for dominant model: Val/Val + Ile/Val vs. Ile/Ile: OR 1.10, 95% CI 1.02–1.19). In conclusion, our meta-analysis suggests that GSTP1 Ile105Val polymorphism may increase susceptibility to breast cancer in Asian population.     

Cyclin D1(CCNDl)A870G 基因多态性与保定地区结肠癌的关系

为了探讨cyclin D1(CCNDl)A870G 基因多态性与保定地区结肠癌患者的年龄、性别、高胆固醇血症、家族史、 病理分型、病理分期的关系,我们从200 例保定地区结肠癌患者和200 例保定地区健康体检者的血中提取DNA,用聚合 酶链反应和限制性酶切片段长度多态体分析对提取的 DNA 进行多肽性分析。结果显示,病例组和对照组 AA\ AG\GG 基因 频率无明显差异。高胆固醇及重度吸烟的结肠癌患者GG 基因型频率明显高于其他基因型,有明显差异（P<0.05）,重度 吸烟及高胆固醇血症在健康体检人群中GG 基因型无明显差异（P>0.05）。由此推断高胆固醇血症及吸烟可作为在cyclin D1(CCNDl)A870G 基因多态性中GG 基因型中结肠癌发生的危险因子,遗传因素的结肠癌患者AA 基因型频率明显高于其 他基因型,有明显差异（P<0.05）。由此推断遗传因素可作为在cyclin D1(CCNDl)A870G 基因多态性中AA 基因型中结肠 癌发生的危险因子,这将为进一步研究结肠癌分子生物学的发生机制提供依据。     

Glutathione S-transferase M1 polymorphism and breast cancer susceptibility: a meta-analysis involving 46,281 subjects

Published data on the association between present/null polymorphism of glutathione S-transferase M1 (GSTM1) and breast cancer risk are inconclusive. To derive a more precise estimation of the relationship, a meta-analysis was performed. Medline, PubMed, Embase, and Web of Science were searched. Crude ORs with 95% CIs were used to assess the strength of association between the GSTM1 present/null polymorphism and breast cancer risk. The pooled ORs were performed for null versus present genotype. A total of 59 studies including 20,993 cases and 25,288 controls were involved in this meta-analysis. Overall, significantly elevated breast cancer risk was associated with null genotype when all studies were pooled into the meta-analysis (OR = 1.10, 95% CI = 1.04–1.16). In the subgroup analysis by ethnicity, significantly increased risks were found for Caucasians (OR = 1.05, 95% CI = 1.00–1.10) and Asians (OR = 1.21, 95% CI = 1.08–1.35). When stratified by population-based studies or hospital-based studies, statistically significantly elevated risks were found among population-based studies (OR = 1.11, 95% CI = 1.03–1.20). In the subgroup analysis by menopausal status, statistically significantly increased risks were found among postmenopausal women (OR = 1.15, 95% CI = 1.04–1.28). In conclusion, this meta-analysis suggests that the GSTM1 null genotype is a low-penetrant risk factor for developing breast cancer.     

Cyclin D1 Pro241Pro (CCND1-G870A) polymorphism is associated with increased cancer risk in human populations: a meta-analysis

The G870A polymorphism in the CCND1 gene may influence cancer risk. However, data from published studies with individual low statistical power have been controversial. To evaluate whether combined evidence shows an association between this polymorphism and cancer, we considered all available studies in a meta-analysis. Sixty studies were combined representing data for 18,411 cases and 22,209 controls. In our meta-analysis, we investigated overall sample and two ethnic populations (Caucasians and Asians) as well as nine cancer subtypes. Individuals who are homozygous for A allele (AA) were found to be associated with significantly increased cancer risk in overall sample [odds ratio (OR), 1.23; 95% confidence interval (95% CI), 1.13-1.33; P 相似文献   

Cyclin D1 gene G870A polymorphism predicts response to neoadjuvant radiotherapy and prognosis in rectal cancer

PURPOSE: To investigate whether CCND1 genetic variations associated with a constitutive nuclear protein may influence either the pathologic response to preoperative RT or the prognosis in a series of rectal cancer patients. METHODS AND MATERIALS: Seventy rectal cancer patients treated by neoadjuvant radiotherapy were included in the study. CCND1 exon 5 mutations were screened, and the G870A polymorphism was assessed for correlation with clinical variables, tumor response, and patient outcome. RESULTS: No exon 5 mutation was found. Concerning the G870A polymorphism, the A/A variant was significantly associated with radiosensitivity (p = 0.022). Moreover, patients harboring the A allele were correlated with a lower risk of local failure (p = 0.017). Also, combination of the G870A polymorphism with the post-therapeutic lymph node status allowed the elaboration of a prognostic index, which accurately distinguished subgroups of patients with predictable recurrence-free (p = 0.003) and overall (p = 0.044) survival. CONCLUSIONS: Although CCND1 exon 5 mutations are rare in rectal cancer, G870A polymorphism is a frequent variation that may predict radiosensitivity and prognosis.     

The p21 Ser31Arg polymorphism and breast cancer risk: a meta-analysis involving 51,236 subjects

Published data on the association between p21 Ser31Arg polymorphism and breast cancer risk are inconclusive. To derive a more precise estimation of the relationship, a meta-analysis was performed. Crude ORs with 95% CIs were used to assess the strength of association between the p21 Ser31Arg polymorphism and breast cancer risk. The pooled ORs were performed for co-dominant model (Ser/Arg vs. Ser/Ser, Arg/Arg vs. Ser/Ser), dominant model (Arg/Arg + Ser/Arg vs. Ser/Ser), and recessive model (Arg/Arg vs. Ser/Arg + Ser/Ser). A total of 21 studies including 22,109 cases and 29,127 controls were involved in this meta-analysis. Overall, no significant associations were found between p21 Ser31Arg polymorphism and breast cancer risk when all studies pooled into the meta-analysis. In the subgroup analysis by ethnicity, significantly increased risk was found for Caucasians (Arg/Arg vs. Ser/Ser: OR 1.496, 95% CI 1.164–1.924; and recessive model: OR 1.492, 95% CI 1.161–1.919). When stratified by study design, statistically significantly elevated risk was found for population-based studies (Ser/Arg vs. Ser/Ser: OR 1.085, 95% CI 1.019–1.156). In conclusion, this meta-analysis suggests that the p21 Ser31Arg polymorphism may be associated with breast cancer development in Caucasian. However, large sample and representative population-based studies with homogeneous breast cancer patients and well-matched controls are warranted to confirm this finding.     

No association between CYP1B1 Val432Leu polymorphism and breast cancer risk: a meta-analysis involving 40,303 subjects

Breast cancer is the most common cancer in women. To date, many publications have evaluated the association between Cytochrome P450 1B1 (CYP1B1) Val432Leu polymorphism and breast cancer risk. However, the results remain inconclusive. In order to derive a more precise estimation of the association, a meta-analysis was performed in this study. By searching Medline, Pubmed, and ISI Web of Knowledge databases, 26 studies including 19,028 cases and 21,275 controls were collected for CYP1B1 Val432Leu polymorphism. Crude ORs with 95% CIs were used to assess the strength of association between CYP1B1 Val432Leu polymorphism and breast cancer risk. The pooled ORs were performed for codominant model, dominant model, and recessive model, respectively. Overall, no significant associations between CYP1B1 Val432Leu polymorphism and breast cancer susceptibility were found for Val/Val versus Leu/Leu (OR = 0.98; 95% CI: 0.90–1.06), Val/Leu versus Leu/Leu (OR = 1.01; 95% CI: 0.93–1.09), Val/Val + Val/Leu versus Leu/Leu (OR = 1.00; 95% CI: 0.93–1.08) and Val/Val versus Val/Leu + Leu/Leu (OR = 0.96; 95% CI: 0.91–1.01). In the stratified analysis by ethnicity, menopausal status and sources of controls, significant associations were still not observed in all genetic models. In conclusion, this meta-analysis provides strong evidence that CYP1B1 Val432Leu polymorphism is not associated with breast cancer risk.     

Lack of significant association between CYP1A1 T3801C polymorphism and breast cancer risk: a meta-analysis involving 25,087 subjects

Breast cancer is the most prevalent cancer in the world, which is a major public health challenge. To date, many publications have evaluated the correlation between Cytochrome P450 1A1 (CYP1A1) T3801C polymorphism and breast cancer risk. However, the results remain inconclusive. In order to derive a more precise estimation of the association, a meta-analysis was performed in this study. By searching Medline, PubMed, and ISI Web of Knowledge databases, 23 studies including 10,520 cases and 14,567 controls were collected for CYP1A1 T3801C polymorphism. The strength of association between CYP1A1 T3801C polymorphism and breast cancer risk was assessed by calculating crude ORs with 95% CIs. The pooled ORs were performed for codominant model, dominant model, and recessive model, respectively. Overall, no significant associations between CYP1A1 T3801C polymorphism and breast cancer susceptibility were found for TT versus CC (OR = 0.93; 95% CI: 0.72–1.19), TC versus CC (OR = 0.95; 95% CI: 0.79–1.14), TT + TC versus CC (OR = 0.93; 95% CI: 0.75–1.15), and TT versus TC + CC (OR = 0.99; 95% CI: 0.87–1.13). In the stratified analysis by ethnicity, menopausal status, and source of controls, no significant associations were detected in all genetic models. In conclusion, this meta-analysis provides strong evidence that CYP1A1 T3801C polymorphism is not associated with breast cancer risk.     

RAD51 G135C polymorphism is associated with breast cancer susceptibility: a meta-analysis involving 22,399 subjects

Several studies have investigated the associations between RAD51 G135C polymorphism and the susceptibility to breast cancer, but results have been inconclusive. In order to derive a more precise estimation of the relationship, a meta-analysis was performed. A total of 17 case control studies, including 12,153 cases and 10,245 controls, were selected. Overall, significant decreased risk was found for the additive model (OR = 0.995, 95% CI = 0.991–0.998) and dominant model (OR = 0.994, 95% CI = 0.991–0.998). In the subgroup analysis by ethnicity, statistically significantly decreased risk was found in Asians (additive model: OR = 0.977, 95% CI = 0.954–1.000 and dominant model: OR = 0.981, 95% CI = 0.963–1.000). In conclusion, this meta-analysis suggests that the RAD51 G135C polymorphism is a low-penetrant risk factor for developing breast cancer.