[Association between folate intake and breast cancer risk among Tehrani women: a case-control study]

Dietary folate deficiency may contribute to tumorogenesis in many sorts of malignancies. By considering the increasing incidence rate of breast cancer in Iran, this study was conducted to investigate the association between dietary folate intake and breast cancer risk. In this case-control study, 177 patients with breast cancer and 169 control subjects with no family history of malignancy were recruited from hospitals affiliated to Shahid-Beheshti University of Medical Sciences, Tehran. Standard questionnaires were used to collect data on demographic characteristics, physical activity, and food frequency consumption for the previous year. Total daily energy and folate intakes were estimated using the Nutritionist IV software. No statistically significant correlation was observed between daily dietary intake of folate and breast cancer risk in the sample population. However, the results showed a significant inverse association between daily intake of dietary folate and risk of breast cancer in postmenopausal women [OR=0.17; 95%CI: 0.035-0.88]. Increases in the strata of daily folate intakes were associated with decreasing trends of ORs in postmenopausal breast cancer risk [P[for trend] =0.036], where the OR of folate intake at the 2[nd] tertile was 0.26 [95%CI: 0.05-1.22] and at the 3[rd] tertile was 0.17 [95%CI: 0.035-0.88]. Based on the findings, folate intake was not correlated with breast cancer risk in the total sample population, whereas higher intakes of folate was inversely associated with postmenopausal breast cancer risk

Association of plasma folate, vitamin B12 and homocysteine levels with hypermethylation status of Eralphagene in primary breast carcinoma

The translation of estrogen receptor- a [ERa] is vital in therapeutic regimens in breast cancer. The repression of its expression could be attributed to regional CpG island methylation in exon1. We aimed to explore the association of plasma levels of folate, vitamin B12 and total homocysteine [tHcy] with the hypermethylation status of ERa genes in breast cancer patients. The hypermethylation status was determined in dissected tissues from 137 primary breast cancer patients aged 28-85 years, using methylation-specific PCR. In addition, the plasma levels of folate and vitamin B12 of the patients were assessed by automated chemiluminescence, and their total plasma homocysteine was determined by HPLC. The logistic regression analysis was used for analyzing the data after adjusting for potential confounding factors. Hypermethylation at ERa was observed in 51.1% of the participants. It was related positively to smoking history and duration of exposure to estradiol, and inversely with ER translation. After adjustments for confounding factors, an inverse association was also found between the hypermethylation status of ERa gene and the plasma levels of folate [OR=0.187; 95%CI, 0.052-0.668] and vitamin B12 [OR=0.185; 95%CI, 0.036-0.953]. The data also showed that the risk of hypermethylation at ERa gene increased with the high plasma levels of tHcy [OR=9.61; 95%CI, 1.26-73.2]. It may be concluded that a high plasma tHcy level can potentially increase the risk of hypermethylation of the ERa gene, while plasma folate and vitamin B12 levels may reduce the risk, in cancer patients