MTHFR polymorphisms, dietary folate intake and breast cancer risk in Chinese women

作者：Gao Chang Ming^*; Tang Jin Hai; Cao Hai Xia; Ding Jian Hua; Wu Jian Zhong; Wang Jie; Liu Yan Ting; Li Su Ping; Su Ping; Matsuo Keitaro; Takezaki Toshiro; Tajima Kazuo

来源：Journal of Human Genetics, 2009, 54(7): 414-418.

DOI：10.1038/jhg.2009.57

• breast cancer
• folate
• genetic polymorphisms
• methylenetetrahydrofolate reductase
• susceptibility

To evaluate the relationship between dietary folate intake and genetic polymorphisms of 5,10-methylenetetrahydrofolate reductase (MTHFR) with reference to breast cancer risk, we conducted a case-control study with 669 cases and 682 population-based controls in the Jiangsu Province of China. MTHFR C677T and A1298C genotypes were identified using PCR-RFLP (restrictrion fragment length polymorphism) methods. Dietary folate intake was assessed using an 83-item food frequency questionnaire. Odds ratios (ORs) were estimated with an unconditional logistic model. The frequencies of MTHFR C677T C/C, C/T and T/T genotypes were 32.37, 48.88 and 18.75% in cases and 37.66, 48.24 and 14.10% in controls, respectively. The difference in distribution was significant (chi(2) = 6.616, P = 0.037), the T/T genotype being associated with an elevated OR (adjusted for age, menopausal status, body mass index (BMI), income, work intensity and status of smoking and drinking) for breast cancer (1.62, 95% confidence interval (95% CI): 1.14-2.30). The frequencies of MTHFR A1298C A/A, A/C and C/C were 71.47, 27.08 and 1.44% in cases and 68.11, 30.13 and 1.76% in controls, respectively, with no significant differences being found (chi(2) 1.716, P = 0.424). A significant inverse relationship was observed between folate intake and breast cancer risk. Compared with the lowest tertile of folate intake, the adjusted OR for breast cancer in the top tertile was 0.70 (95% CI: 0.53-0.92). However, no significant interaction was observed between folate intake and the MTHFR C677T polymorphism. Among individuals with the MTHFR A1298C A/A genotype, adjusted ORs for breast cancer were 0.89 (0.62-1.27) and 1.69 (1.20-2.36) for the second to the third tertile of folate intake compared with the highest folate intake group (tread test, P = 0.0008). The findings of this study suggest that MTHFR genetic polymorphisms and dietary intake of folate may modify susceptibility to breast cancer. Journal of Human Genetics (2009) 54, 414-418; doi: 10.1038/jhg.2009.57; published online 26 June 2009

• 出版日期2009-7
• 单位江苏省肿瘤防治研究所