Dietary Isoflavone Intake, Polymorphisms in the CYP17, CYP19, 17β-HSD1, and SHBG Genes, and Risk of Breast Cancer in Case-Control Studies in Japanese, Japanese Brazilians, and Non-Japanese Brazilians

• Published in: Nutrition and cancer Vol. 62; no. 4; pp. 466 - 475
• Main Authors: Iwasaki, Motoki, Hamada, Gerson Shigeaki, Nishimoto, Ines Nobuko, Netto, Mario Mourao, Motola, Juvenal Jr, Laginha, Fabio Martins, Kasuga, Yoshio, Yokoyama, Shiro, Onuma, Hiroshi, Nishimura, Hideki, Kusama, Ritsu, Kobayashi, Minatsu, Ishihara, Junko, Yamamoto, Seiichiro, Hanaoka, Tomoyuki, Tsugane, Shoichiro
• Format: Journal Article
• Language: English
• Published: Philadelphia, PA Taylor & Francis Group 28-04-2010; Taylor& Francis
• Subjects: Biological and medical sciences; breast neoplasms; case studies; estrogenic properties; Feeding. Feeding behavior; food frequency questionnaires; Fundamental and applied biological sciences. Psychology; genetic polymorphism; Gynecology. Andrology. Obstetrics; hormone receptors; isoflavones; Japanese people; Mammary gland diseases; Medical sciences; molecular sequence data; nutrition-genotype interaction; risk factors; soybean products; traditional foods; Tumors; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Brazil; Japan; South America; America; Isoflavone; Breast disease; Risk; Breast cancer; Malignant tumor; Case control study; Japanese; Mammary gland diseases; Cancerology; Gene; Food intake; Risk factor; Cancer; Polymorphism
• ISSN: 0163-5581; 1532-7914
• DOI: 10.1080/01635580903441279

We tested the hypothesis that polymorphisms in cytochrome P450c17 (CYP17), aromatase (CYP19), 17β-hydroxysteroid dehydrogenase type I (17β-HSD1) and sex hormone-binding globulin (SHBG) genes may modify the association between isoflavone intake and breast cancer risk. We conducted hospital-based, case-control studies in Nagano, Japan and So Paulo, Brazil. A total of 846 pairs (388 Japanese, 79 Japanese Brazilians, and 379 non-Japanese Brazilians) completed validated food frequency questionnaires. Four single nucleotide polymorphisms (SNPs) in CYP17 (rs743572), CYP19 (rs10046), 17β-HSD1 (rs605059), and SHBG (rs6259) genes were genotyped. We found no association between the 4 SNPs and breast cancer risk. In combination analyses of isoflavone intake and SNPs, an inverse association between intake and risk was limited to women with at least one A allele of the rs605059 polymorphism for all 3 populations, albeit without statistical significance. For the rs6259 polymorphism, the inverse association was limited to postmenopausal Japanese with the GG genotype (odds ratio [OR] for highest vs. lowest tertile = 0.50, 95% confidence interval [CI] = 0.29-0.87; P for trend < 0.01), and to non-Japanese Brazilians with at least one A allele (OR for consumers vs. nonconsumer = 0.21, 95% CI = 0.06-0.77). We found no remarkable difference for the rs743572 and rs10046 polymorphisms. Our findings suggest that polymorphisms in the 17β-HSD1 and SHBG genes may modify the association between isoflavone intake and breast cancer risk.