Vitamin D receptor polymorphisms and breast cancer risk in a large population-based case-control study of Caucasian and African-American women.
BACKGROUND
The involvement of vitamin D receptor (VDR), which is a key mediator in the vitamin D pathway, in breast cancer etiology has long been of interest.


METHODS
We examined the association between polymorphisms in the 3' end of the VDR gene, specifically BsmI and Poly(A), and breast cancer risk within a large, population-based, case-control study of breast cancer. Cases (n = 1,631) were Caucasian and African-American women, aged 35 to 64 years, who were diagnosed with incident, invasive breast cancer between July 1994 and April 1998. Control individuals (n = 1,435) were women without breast cancer ascertained through random digit dialing.


RESULTS
Accounting for age, study site, and sampling weights, we observed a significantly increased risk for breast cancer among Caucasian, postmenopausal carriers of the bb genotype of BsmI (odds ratio = 1.53, 95% confidence interval = 1.04 to 2.27). However, no associations with the bb genotype were observed in African-American women. Overall, there were no significant associations between the Poly(A) genotype and breast cancer risk in either racial group. Smoking status (ever/never) modified the association between both the BsmI and Poly(A) genotypes and breast cancer risk. The respective associations between these genotypes and breast cancer risk did not significantly vary by oral contraceptive use, hormone replacement therapy, or body mass index.


CONCLUSIONS
Our results provide additional support for an increased risk for breast cancer in postmenopausal Caucasian women with the BsmI bb genotype and shed light on possible differential effects by menopausal status and race.
Trabert
Britton
B
Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Fairview Ave N, Seattle, Washington 98109-1024, USA.
Malone
Kathleen E
KE
Daling
Janet R
JR
Doody
David R
DR
Bernstein
Leslie
L
Ursin
Giske
G
Marchbanks
Polly A
PA
Strom
Brian L
BL
Humphrey
Mariela C
MC
Ostrander
Elaine A
EA
D000328:Adult; D001741:Black or African American / Q000235:genetics* / Q000706:statistics & numerical data; D001943:Breast Neoplasms / Q000453:epidemiology / Q000235:genetics*; D016022:Case-Control Studies; D015252:Deoxyribonucleases, Type II Site-Specific / Q000235:genetics*; D005260:Female; D005787:Gene Frequency; D005838:Genotype; D006801:Humans; D016015:Logistic Models; D008875:Middle Aged; D016017:Odds Ratio; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D012150:Polymorphism, Restriction Fragment Length; D017698:Postmenopause; D018167:Receptors, Calcitriol / Q000235:genetics*; D018570:Risk Assessment; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects; D014481:United States / Q000453:epidemiology; D044465:White People / Q000235:genetics* / Q000706:statistics & numerical data
D018167:Receptors, Calcitriol; C053864:endodeoxyribonuclease BsmI; D015252:Deoxyribonucleases, Type II Site-Specific