Confirmed BC risk SNPs rs17468277 (CASP8), rs1982073 (TGFB1), rs2981582 (FGFR2), rs13281615 (8q24), rs3817198 (LSP1), rs889312 (MAP3K1), rs3803662 (TOX3), rs13387042 (2q35), rs4973768 (SLC4A7), rs6504950 (COX11) and rs10941679 (5p12) were genotyped for 25 853 BC patients with the available follow-up; 62 other SNPs, which have been suggested as BC risk SNPs by a GWAS or as candidate SNPs from individual studies, were genotyped for replication purposes in subsets of these patients.
In axillary node-positive, HR+, and HER2- early BC, amplifications of FGFR1 gene were strongly associated with increased risk for distant disease, while mutations of MAP3K1 gene were significantly associated with decreased risk.
Genome-wide association studies (GWAS) have demonstrated that the single nucleotide polymorphism (SNP) MAP3K1rs889312 is a genetic susceptibility marker significantly associated with a risk of hormone-related tumors such as breast cancer.
We focus on TNRC9 rs3803662, FGFR2 rs1219648 and rs2981582, MAP3K1rs889312, and 2q35 rs13387042, to replicate in the 4-Corner's Breast Cancer Study of Hispanic (N = 565 cases and 714 controls) and non-Hispanic white (NHW) women (N = 1177 cases and 1330 controls).
SNPs in the mitochondrial ribosomal protein S30 gene (MRPS30), mitogen-activated protein kinase kinase kinase 1 gene (MAP3K1), zinc finger, MIZ-type containing 1 gene (ZMIZ1), and H19, imprinted maternally expressed transcript gene (H19) were associated with breast cancer in whites, and SNPs in the estrogen receptor 1 gene (ESR1) and H19 gene were associated with breast cancer in African Americans.
A genome-wide association study of early-onset breast cancer identifies PFKM as a novel breast cancer gene and supports a common genetic spectrum for breast cancer at any age.
Variants of rs7696175/TLR1, TLR6, rs13281615/8q24, and rs16886165/MAP3K1 were also associated with increased breast cancer risk, with per-allele ORs (95 % CI) of 1.16 (1.00-1.34), 1.15 (1.02-1.29), and 1.15 (1.01-1.29), respectively.
Only 5 out of 9 GWAS breast cancer loci were found to be significantly associated with breast cancer in Tunisians: The rs1219648 (G vs. A allele: OR = 1.36, P = 1 × 10(-3)) and rs2981582 (A vs. G allele: OR = 1.55, P = 3 × 10(-6)) of FGFR2 gene; the rs8051542 of the TNRC9 gene (T vs. C allele: OR = 1.40, P = 4 × 10(-4)); the rs889312 of the MAP3K1 gene (C vs. A allele: OR = 1.33, P = 3 × 10(-3)) and the rs13281615 located on 8q24 (G vs. A allele: OR = 1.21, P = 0.03).
The associations between mitogen-activated protein kinase kinase kinase 1 (MAP3K1) SNPs rs889312 A>C, rs16886165 T>G and breast cancer risk have been widely evaluated, but the results were inconsistent.
Consistent with their breast cancer associations, rs3817198 (LSP1) and rs13281615 (8q) were associated with dense area and percent dense area (all P(x) and P(c) <0.05), and rs889312 (MAP3K1), rs2107425 (H19), and rs17468277 (CASP8) were marginally associated with dense area (some P(x) or P(c) <0.05).
Two of these SNVs, rs252913 and rs331499, located in the MAP3K1/SETD9 gene boundary, were confirmed to be associated with somatic PIK3CA variants in the large cohort with OR 2.97 (1.17-7.75) and 1.76 (1.11-2.77), respectively, notably higher than their BC risk-associated values, both around 1.1.
The genotype of rs2046210 (6q25.1), rs2981582 (EGFR2), rs889312 (MAP3K1), and rs3803662 (TOX3/TNRC9) has no statistical differences in different subtypes of breast cancer.
Significant association with BC was confirmed in 2 SNPs: rs2981582 FGFR2 and rs889312MAP3K1, and the odds ratios of homozygotes with two risk alleles in both SNP's were higher than in heterozygotes with one mutant allele, as follows: FGFR2 TT: 1.953 (95%CI 1.014-3.834, p = 0.049), CT 1.771 (95%CI 1.088-2.899, p = 0.026) and MAP3K1 CC 2.894 (95%CI 1.028-9.566, p = 0.048), AC 1.760 (95%CI 1.108-2.813, p = 0.019).
Using publicly available CGEMS GWAS data to validate significant findings (N = 1,145 cases, N = 1,142 controls), rs889312 near MAP3K1 was confirmed to be associated with breast cancer risk (P = 0.04, OR 1.15, 95% CI 1.01-1.30).
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).
Heterozygote carriers and minor allele homozygote carriers for SNP rs889312 in the MAP3K1 gene were less likely to be lymph node positive at breast cancer diagnosis (P = 0.044) relative to major allele homozygote carriers.
The differences in the effects of the FGFR2 and MAP3K1 SNPs between BRCA1 and BRCA2 carriers point to differences in the biology of BRCA1 and BRCA2 breast cancer tumors and confirm the distinct nature of breast cancer in BRCA1 mutation carriers.
A case‑control study (90‑100 cases; 90‑100 controls) was performed to evaluate five genetic variants of three genes, including FGFR2 (SNPs: rs1219648, rs2981582), TNRC9 (SNPs: rs8051542, rs3803662) and MAP3K1 (SNP: rs889312) as BC risk factors in Pakistani women.
In a previous study, we demonstrated that the minor alleles at three of these SNPs, in FGFR2, TNRC9 and MAP3K1, also confer increased risks of breast cancer for BRCA1 or BRCA2 mutation carriers.
This study confirms that susceptibility variants in FGFR2, TOX3 and MAP3K1 and on chromosome 8q are all associated with increased risk of cancer in individuals with a family history of breast cancer, whereas CASP8 is protective in this context.
In conclusion, this meta-analysis suggests that the MAP3K1rs889312 C allele is a low-penetrant risk factor for developing breast cancer, and there is limited evidence to indicate that MAP3K1rs889312 polymorphism is associated with increased risk of breast cancer in BRCA1 mutation carriers.
Relevant data indicate that SNP rs889312 in MAP3K1 is correlated with BC susceptibility only in BRCA2 mutation carriers, but is not associated with an increased risk in BRCA1 carriers.