MTHFR C677T polymorphism associated with breast cancer susceptibility: a meta-analysis involving 15,260 cases and 20,411 controls

Published data on the association between MTHFR C677T polymorphism 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 MTHFR C677T polymorphism and breast cancer risk. The pooled ORs were performed with co-dominant model (CT vs. CC, TT vs. CC), dominant model (CT + TT vs. CC), and recessive model (TT vs. CC + CT), respectively. A total of 37 studies including 15,260 cases and 20,411 controls were involved in this meta-analysis. Overall, significantly elevated breast cancer risk was associated with TT variant genotype in homozygote comparison and dominant genetic model when all studies were pooled into the meta-analysis (TT vs. CC: OR = 1.11, 95% CI = 1.01–1.23; dominant model: OR = 1.04, 95% CI = 1.00–1.09). In the subgroup analysis by ethnicity, significantly increased risks were found for TT allele carriers among Asians (TT vs. CC: OR = 1.18, 95% CI = 1.04–1.35; recessive model: OR = 1.15, 95% CI = 1.03–1.29). When stratified by study design, statistically significantly elevated risk was found in hospital-based studies (TT vs. CC: OR = 1.18, 95% CI = 1.02–1.38; recessive model: OR = 1.17, 95% CI = 1.05–1.29). In the subgroup analysis by menopausal status, statistically significantly increased risk was found among postmenopausal women (CT vs. CC: OR = 1.12, 95% CI = 1.02–1.23; dominant model: OR = 1.11, 95% CI = 1.01–1.22). In conclusion, this meta-analysis suggests that the MTHFR T allele is a low-penetrant risk factor for developing breast cancer.     

Screening RAD51C nucleotide alterations in patients with a family history of breast and ovarian cancer

Breast cancer is the most prevalent cancer worldwide. Many published articles have evaluated the association between the transforming growth factor beta 1 (TGFB1) T29C 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. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the strength of the association. A total of 12 studies including 10,417 breast cancer cases and 11,455 controls were identified. Overall, no significant associations between the TGFB1 T29C polymorphism and breast cancer risk were found for CC versus TT (OR = 1.00, 95% CI = 0.92–1.09), TC versus TT (OR = 0.98, 95% CI = 0.93–1.05), CC/TC versus TT (OR = 0.99, 95% CI = 0.93–1.05), and CC versus TC/TT (OR = 1.00, 95% CI = 0.93–1.08). In the subgroup analysis by ethnicity, source of controls, and menopausal status, there was still no significant association detected in all genetic models. In conclusion, the present meta-analysis suggests that the TGFB1 T29C polymorphism is not a low-penetrant risk factor for developing breast cancer.     

The association between two polymorphisms of eNOS and breast cancer risk: a meta-analysis

Breast cancer is one of the most common malignant tumors worldwide. Endothelial nitric oxide synthase (eNOS) plays a key role in breast cancer development. The associations between the two eNOS polymorphisms (E298D rs1799983, −786T>C rs2070744) and breast cancer risk are inconclusive. A meta-analysis was performed in this study. By searching Medline, ISI Web of Knowledge, ScienceDirect, EBSCO, CNKI, and SinoMed database, six case–control studies were collected for the eNOS E298D polymorphism (3,038 cases and 2,508 controls) and three case–control studies were eligible for the eNOS −786T>C polymorphism. Crude ORs with 95% CIs were used to assess the strength of association between the two eNOS polymorphisms and breast cancer risk. The pooled ORs were performed for codominant model, dominant model, and recessive model, respectively. Overall, significantly decreased risk was observed for E298D (for EE vs. DD: OR = 0.74, 95% CI = 0.59–0.94; for ED vs. DD: OR = 0.78, 95% CI = 0.61–0.98; for dominant model: OR = 0.77, 95% CI = 0.61–0.96) and −786T > C (for TT vs. CC: OR = 0.60, 95% CI = 0.42–0.86; for dominant model: OR = 0.66, 95% CI = 0.47–0.94). In the subgroup analysis by ethnicity, significant decreased risks were found for E298D (for EE vs. DD: OR = 0.75, 95% CI = 0.56–0.99) and −786T>C (for TT vs. CC: OR = 0.53, 95% CI = 0.35–0.81; for dominant model: OR = 0.61, 95% CI = 0.41–0.91; for recessive model: OR = 0.70, 95% CI = 0.55–0.91) among Caucasians; significant decreased risks were observed for E298D (for ED vs. DD: OR = 0.12, 95% CI = 0.02–0.96; for dominant model: OR = 0.13, 95% CI = 0.02–1.00) among Asians. In conclusion, this meta-analysis suggests that both eNOS E298D and −786T>C polymorphisms are associated with reduced breast cancer risk.     

Association between CYP19 polymorphisms and breast cancer risk: results from 10,592 cases and 11,720 controls

The association of CYP19 gene polymorphisms with breast cancer has been widely reported, but results of previous studies were somewhat contradictory and underpowered. In order to overcome the limitations of individual study and to understand the real situation, we conducted a systematic review and meta-analysis including three CYP19 gene polymorphisms [R264C polymorphism, CYP19_630 3-bp del/Ins polymorphism, and CYP19_681 (TTTA)_n polymorphisms]. A total of 22 studies with 10,592 cases and 11,720 controls were identified, and the results showed that R264C polymorphism was not associated with breast cancer risk in overall (T vs. C: OR = 1.061, 95% CI = 0.929–1.212) or race-based populations (T vs. C for Asian: OR = 1.169, 95% CI = 1.002–1.363; for Caucasian: OR = 0.787, 95% CI = 0.597–1.037); meanwhile, for Asian individuals, 3-bpDel/Ins polymorphism showed a significantly association with breast cancer susceptibility (for allele Del vs. allele Ins: OR = 1.278, 95% CI = 1.066–1.532) while the carriers of allele (TTTA)₁₂ can significantly decrease breast cancer risk (OR = 0.752, 95% CI = 0.603–0.939). Furthermore, the carriers of allele (TTTA)₁₀ were significantly associated with breast cancer susceptibility (OR = 1.515, 95% CI = 1.115–2.058). It can be concluded that potentially functional CYP19_630 3-bp del/Ins polymorphism and CYP19_681 (TTTA)_n polymorphisms may play a low penetrance role in breast cancer susceptibility in an ethnicity-specific manner.     

IGFBP3 A-202C polymorphism and breast cancer susceptibility: a meta-analysis involving 33,557 cases and 45,254 controls

Published data on the association between insulin-like growth factor binding protein 3 (IGFBP3) A-202C 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 them. A total of 27 studies including 33,557 cases and 45,254 controls were involved in this meta-analysis. Overall, significantly elevated breast cancer risk was associated with IGFBP3 C allele when all studies were pooled into the meta-analysis (CC vs. AA: OR = 1.06, 95% CI = 1.02–1.11; dominant model: OR = 1.04, 95% CI = 1.00–1.07). In the subgroup analysis by ethnicity, significantly increased risk was found for Caucasians (AC vs. AA: OR = 1.04, 95% CI = 1.00–1.08; CC vs. AA: OR = 1.05, 95% CI = 1.01–1.10; dominant model: OR = 1.04, 95% CI = 1.00–1.08) and Asians (CC vs. AA: OR = 1.35, 95% CI = 1.02–1.78; recessive model: OR = 1.38, 95% CI = 1.05–1.82). When stratified by study design, statistically significantly elevated risk was found among population-based studies (CC vs. AA: OR = 1.06, 95% CI = 1.01–1.11; dominant model: OR = 1.03, 95% CI = 1.00–1.07). In the subgroup analysis by menopausal status, no statistically significantly increased risk was found among premenopausal or postmenopausal women. In conclusion, this meta-analysis suggests that the IGFBP3 C allele is a low-penetrant risk factor for developing breast cancer.     

Transforming growth factor-β1 polymorphisms and breast cancer risk: a meta-analysis based on 27 case–control studies

The association between transforming growth factor-β1 (TGF-β1) gene polymorphisms and breast cancer risk has been widely reported, but results were somewhat controversial and underpowered. To derive a more precise estimation of the relationship between TGF-β1 polymorphisms and breast cancer risk, we conducted a meta-analysis of all available case–control studies relating the T869C and/or C-509T polymorphisms of the TGF-β1 gene to the risk of developing breast cancer. Eligible articles were identified by search of databases including MEDLINE, PubMed, Web of Science, EMBASE, and Chinese Biomedical Literature database (CBM) for the period up to March 2010. Finally, a total of 17 articles involving 27 case–control studies were identified, 25 with 20,022 cases and 24,423 controls for T869C polymorphism and eight with 10,633 cases and 13,648 controls for C-509T polymorphism. The pooled ORs were performed for the allele contrasts, additive genetic model, dominant genetic model and recessive genetic model, respectively. Subgroup analysis was also performed by ethnicity for T869C polymorphism. With respect to T869C polymorphism, no association was found in overall analysis (C vs. T: OR = 1.033, 95% CI = 0.996–1.072). In the subgroup analysis by ethnicity, significantly increased risk was found in Caucasian population (C vs. T: OR = 1.051, 95% CI = 1.018–1.085; CC vs. TT + TC: OR = 1.083, 95% CI = 1.019–1.151), but not in Asian population (C vs. T: OR = 1.054, 95% CI = 0.983–1.130). With respect to C-509T polymorphism, no significant association with breast cancer risk was demonstrated in overall analysis (T vs. C: OR = 0.986, 95% CI = 0.936–1.039). It can be concluded that potentially functional TGF-Β1 T869C polymorphism may play a low penetrance role in breast cancer susceptibility in an ethnicity-specific manner.     

Association between two polymorphisms of ABCB1 and breast cancer risk in the current studies: a meta-analysis

Previous epidemiological studies have evaluated the association between the ABCB1 polymorphism and the risk of breast cancer with conflicting results. Hence, we conducted a meta-analysis of the ABCB1 gene and risk of breast cancer to obtain the most reliable estimate of the association. PubMed, Embase, and Web of Science databases were searched. A total of eight studies including 3,829 cases and 6,193 controls were identified. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were extracted and pooled to assess the strength of associations between the ABCB1 C3435T and rs2214102 G>A polymorphisms and risk of breast cancer. Of these studies, only one deviated from Hardy–Weinberg equilibrium. Summary estimates indicated that the ABCB1 C3435T polymorphism was not associated with increased risk of breast cancer in the allele contrast model (T vs. C, pooled OR = 1.15; 95% CI = 0.89–1.48); the co-dominant model (CT vs. CC, OR = 1.12 [0.86–1.46] and TT vs. CC, OR = 1.30 [0.79–2.15]); the dominant model (OR = 0.80 [0.63–1.02]; and the recessive model (OR = 0.83 [0.57–1.22]). In the sensitivity analysis by ethnicity, no statistically significant associations were detected in Asians. However, in Caucasian women the T allele contrast model and the TT genotype were each associated with increased risk: T vs. C, pooled OR (95% CI) = 1.26 (1.04–1.52) and TT vs. CC, OR = 1.48 (1.04–2.11). Accordingly, the dominant model yielded statistically significant results (pooled OR = 0.71, 95% CI: 0.52–0.96) but not with the allele contrast model or the co-dominant model. There was evidence of publication bias (P = 0.02 for recessive model). In conclusion, there is limited evidence to indicate that the ABCB1 C3435T and rs2214102 G>A polymorphisms are associated with increased risk of breast cancer.     

MTHFR polymorphisms in gastric cancer and in first-degree relatives of patients with gastric cancer

Two common mutations, 677 C→T and a1298 A→C, in the methylenetetrahydrofolate reductase gene (MTHFR) reduce the activity of MTHFR and folate metabolism. Familial aggregation in a variable but significant proportion of gastric cancer (GC) cases suggests the importance of genetic predisposition in determining risk. In this study, we evaluate MTHFR polymorphisms in 57 patients with a diagnosis of GC, in 37 with a history of GC in first-degree relatives (GC-relatives), and in 454 blood donors. Helicobacter pylori (HP) infection was also determined. An increased risk was found for 677TT in GC patients with respect to blood donors (odds ratio (OR) = 1.98), and statistical significance was sustained when we compared sex–age-matched GC patients and donors (OR = 2.37). The 677TT genotype association with GC was found in women (OR = 3.10), while a reduction in the 667C allele frequency was present in both the sex. No statistically significant association was detected when 677–1298 genotype was stratified by sex and age. Men of GC-relatives showed a higher 1298C allele frequency than donors (OR = 4.38). Between GC and GC-relatives, HP infection frequency was similar. In conclusion, overall findings support the hypothesis that folate plays a role in GC risk. GC-relatives evidence a similar 677TT frequency to that found in the general population.     

亚甲基四氢叶酸还原酶基因单核苷酸多态与乳腺癌风险

目的 内研究亚甲基四氢叶酸还原酶(MTHFR)基因单核苷酸多态与女性乳腺癌风险的关系。方法 以聚合酶链反应(PCR)和限制性片段长度多态性(RFLF)分析方法,检测了217例乳腺癌患者和218例配对的正常对照者MTHFR因C677T和A1298C基因型,并比较不同基因型与乳腺癌风险的关系。结果 677TT基因型频率在乳腺癌患者和正常对照中的分布差异有显著性(32．7％比24．8％,P=0．02)。携带MTHFR 677TT基因犁者与携带MTHFR 677CC基因型者比较,前者罹患乳腺癌的风险增加1,84倍(95％ C：1．09～3．14)。MTHFR 677CT基因型以及MTHFR A1298C多态与乳腺癌风险不相关。结论 MTHFR基因677C→T突变是女性乳腺癌的遗传易感因素。     

Lack of association of CYP1A2-164 A/C polymorphism with breast cancer susceptibility: a meta-analysis involving 17,600 subjects

Published data on the association between cytochrome P-450 1A2 (CYP1A2)-164 A/C polymorphism 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 CYP1A2-164 A/C polymorphism and breast cancer risk. The pooled ORs were performed for co-dominant model (AC versus AA, CC versus AA), dominant model (CC + AC versus AA), and recessive model (CC versus AA + AC), respectively. A total of 9 studies including 7,580 cases and 10,020 controls were involved in this meta-analysis. Overall, no significantly elevated breast cancer risk was found in all genetic models when all studies were pooled into the meta-analysis (AC versus AA: OR = 1.02, 95% CI = 0.92–1.13; CC versus AA: OR = 1.17, 95% CI = 0.83–1.64; dominant model: OR = 1.07, 95% CI = 0.93–1.23; and recessive model: OR = 1.13, 95% CI = 0.82–1.55). In the subgroup analysis by ethnicity or source of controls, there was still no significant association detected in all genetic models. In conclusion, upto date, there is still no enough evidence to indicate the association of CYP1A2-164 A/C polymorphism and breast cancer development.     

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.     

Lack of an association between AURKA T91A polymorphisms and breast cancer: a meta-analysis involving 32,141 subjects

Several studies have investigated the associations between AURKA T91A polymorphism and the susceptibility to breast cancer, but the results have been inconclusive. To derive a more precise estimation of the relationship, a meta-analysis was performed. A total of 11 case–control studies, including 14,361 cases and 17,780 controls, were selected. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of association in the additive model, dominant model, and recessive model. When all the studies were pooled into the meta-analysis, there was no evidence showing a significant association between AURKA T91A polymorphism and breast cancer risk (for additive model, OR = 0.839, 95% CI = 0.678–1.038; for dominant model: OR = 0.890, 95% CI = 0.757–1.074; and for recessive model: OR = 0.987, 95% CI = 0.963–1.012). In the subgroup analysis by ethnicity, significantly decreased risks were found for Asians (additive model, OR = 0.857, 95% CI = 0.742–0.991). When stratified by study design, no significant association was found between the polymorphism and breast cancer risk. In conclusion, this meta-analysis indicates that the AURKA T91A polymorphism is not a risk factor for developing breast cancer.     

No association between SOD2 Val16Ala polymorphism and breast cancer susceptibility: a meta-analysis based on 9,710 cases and 11,041 controls

Breast cancer is the most common cancer in women worldwide, but its etiology is still unclear. It is believed that oxidative stress plays an essential role in the development of breast cancer, while SOD2 is one of the primary enzymes that directly convert potential harmful oxidizing species to harmless metabolites. The association of SOD2 Val16Ala polymorphism and breast cancer risk has been widely reported, but results of previous studies were somewhat contradictory and underpowered. To overcome the limitations of individual study and to understand the real situation, we conducted a systematic review and meta-analysis toward the association between SOD2 Val16Ala polymorphism and breast cancer. Through retrieving MEDLINE, PubMed, Embase, and Web of Science, a total of 17 studies with 9,710 cases and 11,041 controls were identified. The results showed that no significant associations were found for the allele contrast (allele Ala vs. allele Val: OR = 1.020, 95% CI = 0.979–1.062), additive genetic model (Ala/Ala vs. Val/Val: OR = 1.091, 95% CI = 0.969–1.229), dominant genetic model (Ala/Ala +Ala/Val vs. Val/Val: OR = 1.045, 95% CI = 0.961–1.136), and recessive genetic model (Ala/Ala vs. Val/Val +Ala/Val: OR = 1.027, 95% CI = 0.956–1.102). In the stratified analysis by ethnicity and menopausal status, significant associations were also not detected in all genetic models. Conclusively, this meta-analysis strongly suggests that SOD2 Val16Ala polymorphism is not associated with breast cancer susceptibility.     

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.     

Lack of association between CYP17 MspA1 polymorphism and breast cancer risk: a meta-analysis of 22,090 cases and 28,498 controls

Epidemiological studies have evaluated the association between CYP17 MspA1 polymorphism and breast cancer risk. However, the results remain conflicting rather than conclusive. To derive a more precise estimation of the relationship, we performed this meta-analysis. Systematic searches of the PubMed and Medline databases were performed. A total of 35 studies including 22,090 cases and 28,498 controls were identified. Genotype distributions of CYP17 in the controls of all studies were in agreement with Hardy–Weinberg equilibrium (HWE) except for three studies. When all 35 studies were pooled into the meta-analysis, there was no evidence for significant association between CYP17 MspA1 polymorphism and breast cancer risk (for A1/A2 vs. A1/A1: OR = 1.00, 95% CI = 0.96–1.04; for A2/A2 vs. A1/A1: OR = 1.03, 95% CI = 0.97–1.08; for dominant model: OR = 1.01, 95% CI = 0.97–1.05; for recessive model: OR = 1.03, 95% CI = 0.98–1.08). In the subgroup analyses by ethnicity, menopausal status and source of controls, no significant associations were found in all genetic models. When sensitivity analyses were performed by excluding HWE-violating studies, all the results were not materially altered. In summary, the meta-analysis strongly suggests that CYP17 MspA1 polymorphism is not associated with increased breast cancer risk.     

Lack of association between HER2 codon 655 polymorphism and breast cancer susceptibility: meta-analysis of 22 studies involving 19,341 subjects

Epidemiological studies have investigated the association between HER2 codon 655 polymorphism and breast cancer susceptibility. However, the results are still inconclusive. To obtain a more precise estimation of the relationship, this meta-analysis was performed. A total of 22 studies including 9,209 cases and 10,132 controls were collected. The strength of association between HER2 codon 655 polymorphism and breast cancer susceptibility was assessed by calculating crude ORs with 95% CIs. When all the 22 studies were pooled into the meta-analysis, there was no evidence for significant association between HER2 codon 655 polymorphism and breast cancer susceptibility (for Val/Ile vs. Ile/Ile: OR = 1.069, 95% CI = 0.976–1.172; for Val/Val vs. Ile/Ile: OR = 1.191, 95% CI = 0.922–1.538; for dominant model: OR = 1.093, 95% CI = 0.991–1.206; for recessive model: OR = 1.141, 95% CI = 0.902–1.444). In the subgroup analysis by the source of controls and ethnicity, no significant increased risk was found in all genetic models. However, the current results indicated the modest association between the HER2 Ile655Val polymorphism and Asian population (Val/Ile vs. Ile/Ile: OR = 1.207, CI = 1.006–1.450). In summary, the meta-analysis suggests that HER2 codon 655 polymorphism is not associated with the increased breast cancer risk.     

No association between CYP17 T-34C polymorphism and breast cancer risk: a meta-analysis involving 58,814 subjects

Breast cancer is one of the most common malignant tumors worldwide. To date, many articles have evaluated the association between Cytochrome P450c17 (CYP17) T-34C 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, ISI Web of Knowledge, Cochrane, ScienceDirect, EBSCO, CNKI, and SinoMed databases, 43 studies including 26,008 cases and 32,806 controls were collected for CYP17 T-34C polymorphism. Crude ORs with 95% CIs were used to assess the strength of association between CYP17 T-34C polymorphism and breast cancer risk. The pooled ORs were performed for codominant model, dominant model, and recessive model, respectively. Overall, no significant associations between CYP17 T-34C polymorphism and breast cancer susceptibility were found for TT versus CC (OR = 0.96; 95% CI: 0.89–1.05), TC versus CC (OR = 0.97; 95% CI: 0.89–1.06), TT + TC versus CC (OR = 0.97; 95% CI: 0.89–1.05) and TT versus TC + CC (OR = 0.98; 95% CI: 0.93–1.03). In the stratified analysis by ethnicity, menopausal status, and sources of controls, significant associations were still not detected in all genetic models. In conclusion, this meta-analysis strongly suggests that CYP17 T-34C polymorphism is not associated with breast cancer risk.     

No significant association between the TP53 codon 72 polymorphism and breast cancer risk: a meta-analysis of 21 studies involving 24,063 subjects

Conflicting data have been published as to the possible association between polymorphism in codon 72 of the TP53 tumor suppressor gene and the risk of developing breast cancer. In order to address this question, we carried out a meta-analysis of 21 studies of and this polymorphism and breast cancer risk, which collectively included 12,601 cases and 11,462 controls. Studies were identified by searching the Medline, PubMed, Embase, and ISI Web of Knowledge databases. The strength of association between the TP53 codon 72 polymorphism and breast cancer risk was assessed by calculating crude OR values with 95% CIs, with pooled OR values calculated separately for three genetic inheritance models. We found no significant association between TP53 codon 72 polymorphism and breast cancer risk for either the codominant inheritance model (Pro/Arg vs. Pro/Pro: OR = 1.063, 95% CI = 0.967–1.169; Arg/Arg vs. Pro/Pro: OR = 1.245, 95% CI = 0.997–1.554), the dominant model (OR = 1.146, 95% CI = 0.979–1.340), or the recessive model (OR = 1.179, 95% CI = 1.020–1.362). Stratified analysis by ethnicity and source of controls similarly revealed no significant association for any of the genetic models. In summary, this meta-analysis provides strong evidence that the TP53 codon 72 polymorphism is not associated with the risk of developing breast cancer.     

FASLG polymorphism is associated with cancer risk

Many studies have reported the association between the FASLG –844T/C polymorphism and cancer risk, but the data are remaining controversial. A pooled analysis was performed to assess this relationship comprehensively. Medline, PubMed, Embase and Web of Science were searched, and data were extracted and cross-checked independently by three authors. A total of 18 published studies including 22389 subjects were involved in this analysis. Overall, the –844C allele was associated with a significantly increased cancer risk (for CC versus TT: OR = 1.23, 95% confidence interval (CI) = 1.04–1.45; for CC + TC versus TT: OR = 1.15, 95% CI = 1.01–1.30; for CC versus TT + TC: OR = 1.20, 95% CI = 1.05–1.38). In the subgroup analysis by ethnicity, significantly elevated risks were found among Asians (for CC versus TT: OR = 1.61, 95% CI = 1.37–1.89; for CC + TC versus TT: OR = 1.36, 95% CI = 1.16–1.60; for CC versus TT + TC: OR = 1.44, 95% CI = 1.22–1.70). In the subgroup analysis by study design, significantly increased risks were found among population-based case-control studies (for CC versus TT: OR = 1.40, 95% CI = 1.06–1.84; for CC + TC versus TT: OR = 1.25, 95% CI = 1.01–1.55; for CC versus TT + TC: OR = 1.31, 95% CI = 1.06–1.61). These findings indicate that the FASLG –844C allele is emerging as a low-penetrant cancer susceptibility allele for cancer development. However, more comprehensive understanding of the association would certainly have an immense prospect in the promising field of individualised preventive care.     

STK15 F31I polymorphism is associated with breast cancer risk: a meta-analysis involving 25,014 subjects

Published data on the association between STK15 F31I polymorphism and breast cancer risk are inconclusive. In order to derive a more precise estimation of the relationship, a meta-analysis was performed. Medline, PubMed, Embase, Web of Science, and Chinese Biomedicine Database were searched. Crude ORs with 95% CIs were used to assess the strength of association between the STK15 F31I polymorphism and breast cancer risk. The pooled ORs were performed for codominant model (FI vs. FF; II vs. FF), dominant model (FI + II vs. FF), and recessive model (II vs. FI + FF), respectively. A total of 10 studies including 10,537 cases and 14,477 controls were involved in this meta-analysis. Overall, significantly elevated breast cancer risk was associated with II variant genotype in homozygote comparison and recessive genetic model when all studies were pooled into the meta-analysis (for II vs. FF: OR = 1.23, 95% CI = 1.10–1.37; for recessive model: OR = 1.21, 95% CI = 1.05–1.40). In the subgroup analysis by ethnicity, significantly increased risks were found for II allele carriers among Caucasians (for II vs. FF: OR = 1.24, 95% CI = 1.08–1.43; for recessive model: OR = 1.21, 95% CI = 1.00–1.45); significantly increased risks were also found among Asians for II versus FF (OR = 1.21; 95% CI = 1.01–1.45). In conclusion, this meta-analysis suggests that the STK15 31II allele is a low-penetrant risk factor for developing breast cancer.