Our meta-analysis suggested that there is no significant association between MTHFR gene 1298A>C polymorphism and breast cancer susceptibility for overall population.
Compared with the major genotype, the MTHFR 677 T allele carriers have reduced all-cause mortality and breast cancer-specific mortality in a dominant model [hazard ratio (95% confidence interval): 0.69 (0.49-0.98) and 0.58 (0.38-0.89), respectively].
However, among postmenopausal women, there was an increase in breast cancer risk for women who were homozygote TT for MTHFRC677T and had high lifetime alcohol intake (>or=1,161.84 oz; OR, 1.92; 95% CI, 1.13-3.28) and for those who had a high number of drinks per drinking day (>1.91 drinks/day; OR, 1.80; 95% CI, 1.03-3.28) compared with nondrinkers who were homozygote CC.
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.
In the subgroup analysis based on ethnicity, a significant association of breast cancer and/or ovarian cancer risk with <i>MTHFR C677T</i> polymorphism was observed in Asians.
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.
Our aims were to investigate whether MTHFRC677T was associated with postmenopausal breast cancer risk and whether this relation was modified by intakes of folate, methionine, vitamins B(2), B(6), and B(12), and alcohol.
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.
The presence of MTR A2756G mutant allele and MTHFRC677T mutant allele in carriers was associated with increased breast cancer risk [odds ration, 3.2 (P=0.16; 95% confidence interval, 0.76-13.9) and 3.9 (P=0.09; 95% confidence interval, 0.93-16.3), respectively].
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].
Our aim was to study the association between genetic polymorphisms of MTHFR at two sites (C677T and A1298C) and their haplotypes and the risk of breast cancer among Jordanian females.
Besides, MTHFRrs9651118 CC genotype was significantly associated with survival in breast cancer cases (adjusted hazard ratio (HR) = 0.63, 95 % CI 0.40-0.99).
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.
Conversely, for women over 50, the risk of breast cancer development was statistically associated with the MTHFR 677CT genotype, but especially significant was risk associated with the presence of the polymorphic allele of cSHMT C1420T (P = 0.0120) and the protective effect associated with the RFC1 G80A polymorphism allele (P = 0.0021), was restrict to this age group.