[show abstract][hide abstract] ABSTRACT: BACKGROUND: Recently, 41 new genetic susceptibility loci for breast cancer risk were identified in a genome-wide association study conducted in European descendants. Most of these risk variants have not been directly replicated in Asian populations. METHODS: We evaluated nine of those non-replication loci in East Asians in order to identify new risk variants for breast cancer in these regions. First, we analyzed single nucleotide polymorphisms (SNPs) in these regions using data from two GWAS conducted among Chinese and Korean women, including 5,083 cases and 4,376 controls (Stage 1). In each region we selected a SNP showing the strongest association with breast cancer risk for replication in an independent set of 7,294 cases and 9,404 controls of East Asian descents (Stage 2). Logistic regression models were used to calculate adjusted odds ratios (OR) and 95% confidence intervals (CI) as a measure of the association of breast cancer risk and genetic variants. RESULTS: Two SNPs were replicated in Stage 2 at P < 0.05: rs1419026 at 6q14 (per allele OR = 1.07, 95% CI: 1.03-1.12, P = 3.0×10-4) and rs941827 at 10q25 (OR = 0.92, 95% CI: 0.89-0.96, P = 5.3×10-5). The association with rs941827 remained highly statistically significant after adjusting for the risk variant identified initially in women of European ancestry (OR = 0.88, 95% CI: 0.82-0.97, P = 5.3×10-5). CONCLUSIONS: We identified a new breast cancer risk variant at 10q25 in East Asian women. Impact: Results from this study improve the understanding of the genetic basis for breast cancer.
Cancer Epidemiology Biomarkers & Prevention 05/2013; · 4.56 Impact Factor
[show abstract][hide abstract] ABSTRACT: In a consortium including 23 637 breast cancer patients and 25 579 controls of East Asian ancestry, we investigated 70 single-nucleotide polymorphisms (SNPs) in 67 independent breast cancer susceptibility loci recently identified by genome-wide association studies (GWASs) conducted primarily in European-ancestry populations. SNPs in 31 loci showed an association with breast cancer risk at P < 0.05 in a direction consistent with that reported previously. Twenty-one of them remained statistically significant after adjusting for multiple comparisons with the Bonferroni-corrected significance level of <0.0015. Eight of the 70 SNPs showed a significantly different association with breast cancer risk by estrogen receptor (ER) status at P < 0.05. With the exception of rs2046210 at 6q25.1, the seven other SNPs showed a stronger association with ER-positive than ER-negative cancer. This study replicated all five genetic risk variants initially identified in Asians and provided evidence for associations of breast cancer risk in the East Asian population with nearly half of the genetic risk variants initially reported in GWASs conducted in European descendants. Taken together, these common genetic risk variants explain ∼10% of excess familial risk of breast cancer in Asian populations.
Human Molecular Genetics 03/2013; · 7.69 Impact Factor
[show abstract][hide abstract] ABSTRACT: Although the role of miRNA in cancer development and progression has been well established, the association between genetic variants in miRNA biogenesis pathway genes and breast cancer risk has been yet unclear.
We analyzed data from two genome-wide association studies conducted in East Asian women including 5,066 cases and 4,337 controls. Among the single-nucleotide polymorphisms (SNP), which were directly genotyped or imputed, we selected 237 SNPs in 32 genes involved in miRNA biogenesis pathway and its regulation.
Although eight SNPs were nominally associated with breast cancer risk in combined samples (P < 0.05), none of them were significant after adjustment for multiple comparisons.
The common genetic variants in miRNA biogenesis pathway genes may not be associated with breast cancer risk.
This study suggests no association between the polymorphisms in miRNA biogenesis pathway genes and breast cancer risk. Studies with large sample size and more genetic variants should be warranted to adequately evaluate the potential association.
[show abstract][hide abstract] ABSTRACT: Although approximately 25 common genetic susceptibility loci have been identified to be independently associated with breast cancer risk through genome-wide association studies (GWAS), the genetic risk variants reported to date only explain a small fraction of the heritability of breast cancer. Furthermore, GWAS-identified loci were primarily identified in women of European descent.
To evaluate previously identified loci in Korean women and to identify additional novel breast cancer susceptibility variants, we conducted a three-stage GWAS that included 6,322 cases and 5,897 controls.
In the validation study using Stage I of the 2,273 cases and 2,052 controls, seven GWAS-identified loci [5q11.2/MAP3K1 (rs889312 and rs16886165), 5p15.2/ROPN1L (rs1092913), 5q12/MRPS30 (rs7716600), 6q25.1/ESR1 (rs2046210 and rs3734802), 8q24.21 (rs1562430), 10q26.13/FGFR2 (rs10736303), and 16q12.1/TOX3 (rs4784227 and rs3803662)] were significantly associated with breast cancer risk in Korean women (Ptrend < 0.05). To identify additional genetic risk variants, we selected the most promising 17 SNPs in Stage I and replicated these SNPs in 2,052 cases and 2,169 controls (Stage II). Four SNPs were further evaluated in 1,997 cases and 1,676 controls (Stage III). SNP rs13393577 at chromosome 2q34, located in the Epidermal Growth Factor Receptor 4 (ERBB4) gene, showed a consistent association with breast cancer risk with combined odds ratios (95% CI) of 1.53 (1.37-1.70) (combined P for trend = 8.8 × 10-14).
This study shows that seven breast cancer susceptibility loci, which were previously identified in European and/or Chinese populations, could be directly replicated in Korean women. Furthermore, this study provides strong evidence implicating rs13393577 at 2q34 as a new risk variant for breast cancer.
Breast cancer research: BCR 03/2012; 14(2):R56. · 5.87 Impact Factor
[show abstract][hide abstract] ABSTRACT: Genetic factors play an important role in the etiology of both sporadic and familial breast cancer. We aimed to discover novel genetic susceptibility loci for breast cancer. We conducted a four-stage genome-wide association study (GWAS) in 19,091 cases and 20,606 controls of East-Asian descent including Chinese, Korean, and Japanese women. After analyzing 690,947 SNPs in 2,918 cases and 2,324 controls, we evaluated 5,365 SNPs for replication in 3,972 cases and 3,852 controls. Ninety-four SNPs were further evaluated in 5,203 cases and 5,138 controls, and finally the top 22 SNPs were investigated in up to 17,423 additional subjects (7,489 cases and 9,934 controls). SNP rs9485372, near the TGF-β activated kinase (TAB2) gene in chromosome 6q25.1, showed a consistent association with breast cancer risk across all four stages, with a P-value of 3.8×10(-12) in the combined analysis of all samples. Adjusted odds ratios (95% confidence intervals) were 0.89 (0.85-0.94) and 0.80 (0.75-0.86) for the A/G and A/A genotypes, respectively, compared with the genotype G/G. SNP rs9383951 (P = 1.9×10(-6) from the combined analysis of all samples), located in intron 5 of the ESR1 gene, and SNP rs7107217 (P = 4.6×10(-7)), located at 11q24.3, also showed a consistent association in each of the four stages. This study provides strong evidence for a novel breast cancer susceptibility locus represented by rs9485372, near the TAB2 gene (6q25.1), and identifies two possible susceptibility loci located in the ESR1 gene and 11q24.3, respectively.
[show abstract][hide abstract] ABSTRACT: Although approximately 20 common genetic susceptibility loci have been identified for breast cancer risk through genome-wide association studies (GWASs), genetic risk variants reported to date explain only a small fraction of heritability for this common cancer. We conducted a four-stage GWAS including 17 153 cases and 16 943 controls among East-Asian women to search for new genetic risk factors for breast cancer. After analyzing 684 457 SNPs in 2062 cases and 2066 controls (Stage I), we selected for replication among 5969 Chinese women (4146 cases and 1823 controls) the top 49 SNPs that had neither been reported previously nor were in strong linkage disequilibrium with reported SNPs (Stage II). Three SNPs were further evaluated in up to 13 152 Chinese and Japanese women (6436 cases and 6716 controls) (Stage III). Finally, two SNPs were evaluated in 10 847 Korean women (4509 cases and 6338 controls) (Stage IV). SNP rs10822013 on chromosome 10q21.2, located in the zinc finger protein 365 (ZNF365) gene, showed a consistent association with breast cancer risk in all four stages with a combined per-risk allele odds ratio of 1.10 (95% CI: 1.07-1.14) (P-value for trend = 5.87 × 10(-9)). In vitro electrophoretic mobility shift assays demonstrated the potential functional significance of rs10822013. Our results strongly implicate rs10822013 at 10q21.2 as a genetic risk variant for breast cancer among East-Asian women.
Human Molecular Genetics 09/2011; 20(24):4991-9. · 7.69 Impact Factor