Premenopausal women with the MTHFR polymorphism had a threefold increased breast cancer risk (OR = 2.8; 95%CI: 1.02-7.51) compared to the clinic-based controls with benign breast disease.
Likewise, the MTHFR T677T genotype showed a 2.5-fold increased risk for breast cancer and the C1298C genotype showed a 1.9-fold increased risk for breast cancer.
We evaluated MTHFR genotypes and breast cancer survival in a cohort of 1067 Chinese women diagnosed with breast cancer between 1996 and 1998 who received surgery and chemotherapy.
Additionally, we summarized breast cancer risk associated with the following genetic factors: breast cancer susceptibility high-penetrance genes (BRCA1, BRCA2, p53, PTEN, ATM, NBS1 or LKB1) and low-penetrance genes such as cytochrome P450 genes (CYP1A1, CYP2D6, CYP19), glutathione S-transferase family (GSTM1, GSTP1), alcohol and one-carbon metabolism genes (ADH1C and MTHFR), DNA repair genes (XRCC1, XRCC3, ERCC4/XPF) and genes encoding cell signaling molecules (PR, ER, TNFalpha or HSP70).
The results of this study suggest that the MTHFR 677T variant genotype per se may have no overall association with breast cancer risk, but a sizable association could be observed in the presence of relevant environmental exposure.
A total of 42 women with breast cancer as well as healthy controls were investigated and results showed that p53 codon 72 polymorphism is statistically significantly associated with breast cancer (OR for Arg/Arg to non-Arg/Arg was 6.66, P = 0.0001 at 95% CI 2.63-16.9), but not Her 2 and MTHFR polymorphisms are associated with breast cancer (OR for Ile/Ile to non-Ile/Ile was 1.33, P = 0.54 at 95% CI 0.52-3.38 and OR for T/T versus non-T/T was 1.07, P = 0.89 at 95% CI 0.35-3.25).
In this case-controlled study, a possible effect of the common MTHFRC677T (ala-->val) polymorphism on breast cancer susceptibility in Turkish patients was investigated.
The MTHFR 677T and 1298C variant alleles were associated with decreased risk for breast cancer [adjusted ORs were 0.81 (95% CI: 0.54-1.21) and 0.57 (95% CI: 0.36-0.89) for 677CT + TT genotypes and 1298AC + CC genotypes, respectively].
A meta-analysis of 18 case-control studies investigating the association between the C677T and the A1298C polymorphisms of the MTHFR gene and breast cancer (BC) was carried out.
We conducted a meta-analysis to summarize the available evidence from observational studies on this issue and a meta-analysis of the association between a common polymorphism in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene, a key enzyme in folate metabolism, and breast cancer risk.
The MTHFR 677T and 1298C variant alleles were associated with decreased risk for breast cancer [adjusted ORs were 0.81 (95% CI: 0.54-1.21) and 0.57 (95% CI: 0.36-0.89) for 677CT + TT genotypes and 1298AC + CC genotypes, respectively].
Genetic polymorphisms of glutathione S-transferase (GST) genes including GSTT1 positive/null, GSTM1 positive/null, and GSTP1 A313G, and genes for reduced folate carrier 1 G80A (RFC1 G80A), methylenetetrahydrofolate reductaseC677T (MTHFRC677T), and breast cancer resistant protein C421A (BCRP C421A) were determined for 26 patients by the polymerase chain reaction (PCR) method or by direct sequencing.
Our results suggest that GSTP1 and MTHFR genotypes may be consider relevant and independent factors of toxicity in adjuvant anthracycline-based treatment of breast cancer.
We previously reported that polymorphisms in methylenetetrahydrofolate reductase (MTHFR) in one-carbon pathway were associated with breast cancer risk in the population-based Long Island Breast Cancer Study Project.
We postulate that such differences are related to variations in chemotherapy schemes between hematological and breast cancers and their differential interaction with the MTHFR route.