title: Associations between vitamin D receptor (VDR) gene polymorphisms and colorectal cancer risk and effect modifications of dietary calcium and vitamin D in a Japanese population.
abstract: Much interest has been drawn to possible associations between vitamin D receptor (VDR) gene polymorphisms and colorectal cancer risk in conjunction with potentially protective effects of calcium and vitamin D. In a study of 685 cases of colorectal cancer and 778 community controls in Japan, we examined the associations of the FokI, BsmI, ApaI, and TaqI polymorphisms with colorectal cancer risk and effect modification by dietary calcium and vitamin D. Genotypes were determined by the PCR-RFLP method. The ApaI polymorphism seemed to be associated with a decreased risk of colorectal cancer, particularly of rectal cancer. The adjusted odds ratio of colorectal cancer for the ApaI AA and Aa genotypes combined versus the aa genotype was 0.83 (95% confidence interval [CI] 0.67-1.02), and the corresponding value for rectal cancer was 0.75 (95%CI 0.56-0.99). A decreased risk of colorectal cancer for the ApaI AA and Aa genotypes combined was more evident in individuals with high calcium intake (interaction p=0.055). The FokI polymorphism seemed to be associated with a decreased risk of colon cancer among those with high vitamin D intake (interaction p=0.09). The BsmI and TaqI polymorphisms were unrelated to colorectal cancer risk, and the null associations were not modified by calcium or vitamin D intake. In conclusion, the ApaI polymorphism may be associated with a decreased risk of colorectal cancer in Japanese, dependent on dietary calcium intake.
authors.affiliation: Department of Preventive Medicine, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan E-mail : skono@med.kyushu-u.jp.
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Takeshige
authors.forename: Guang
authors.initials: G
authors.lastname: Yin
authors.forename: Keizo
authors.initials: K
authors.lastname: Ohnaka
authors.forename: Suminori
authors.initials: S
authors.lastname: Kono
authors.forename: Takashi
authors.initials: T
authors.lastname: Ueki
authors.forename: Masao
authors.initials: M
authors.lastname: Tanaka
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Maehara
authors.forename: Takeshi
authors.initials: T
authors.lastname: Okamura
authors.forename: Koji
authors.initials: K
authors.lastname: Ikejiri
authors.forename: Takafumi
authors.initials: T
authors.lastname: Maekawa
authors.forename: Yohichi
authors.initials: Y
authors.lastname: Yasunami
authors.forename: Kenji
authors.initials: K
authors.lastname: Takenaka
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Ichimiya
authors.forename: Reiji
authors.initials: R
authors.lastname: Terasaka
mesh_terms: D002136:Calcium, Dietary / Q000378:metabolism*; D016022:Case-Control Studies; D015179:Colorectal Neoplasms / Q000235:genetics* / Q000378:metabolism; D005260:Female; D020022:Genetic Predisposition to Disease / Q000235:genetics*; D005838:Genotype; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic / Q000235:genetics*; D018167:Receptors, Calcitriol / Q000235:genetics*; D012306:Risk; D012307:Risk Factors; D014807:Vitamin D / Q000378:metabolism*
chemical_list: D002136:Calcium, Dietary; D018167:Receptors, Calcitriol; C579457:VDR protein, human; D014807:Vitamin D