Selected estrogen receptor 1 and androgen receptor gene polymorphisms in relation to risk of breast cancer and fibrocystic breast conditions among Chinese women.
BACKGROUND
Polymorphisms in sex hormone receptor-encoding genes may alter the activity of sex hormone receptors and thereby affect susceptibility to breast cancer and related outcomes.


METHODS
In a case-control study of women from Shanghai, China, we examined the risk of breast cancer and fibrocystic breast conditions associated with the ESR1 PvuII (rs2234693) and XbaI (rs9340799) and AR CAG repeat ((CAG)(n)) and GGC repeat ((GGC)(n)) polymorphisms among 614 women with breast cancer, 467 women with fibrocystic conditions, and 879 women without breast disease. We also evaluated whether risk differed by the presence/absence of proliferative changes (in the extratumoral epithelium or fibrocystic lesion), menopausal status, or body mass index (BMI). Age-adjusted odds ratios (ORs) and 95% confidence intervals (95% CI) were calculated using logistic regression.


RESULTS
Only associations with AR (CAG)(n) and (GGC)(n) genotypes were detected. Allocating AR (CAG)(n) genotypes into six categories, with the (CAG)(22-24)/(CAG)(22-24) genotype category designated as the reference group, the (CAG)(>24)/(CAG)(>24) genotype category was associated with an increased risk of fibrocystic breast conditions (OR, 1.8; 95% CI, 1.1-3.0). Relative to the AR (GGC)(17)/(GGC)(17) genotype, the (GGC)(17)/(GGC)(14) genotype was associated with elevated risks of incident breast cancer (OR, 2.6; 95% CI, 1.3-5.4) and fibrocystic conditions (OR, 2.3; 95% CI, 1.1-4.5). Results did not differ according to proliferation status, menopausal status, or BMI.


CONCLUSIONS
Although these data lend support for a link between AR variation and breast disease development, given the low frequency of the putative risk-conferring genotypes and other constraints, further confirmation of our results is needed.
Sakoda
Lori C
LC
Program in Epidemiology, Division of Public Health Sciences, Fred Hutchinson Cancer Research Center, Seattle, WA 98109-1024, USA.
Blackston
Christie R
CR
Doherty
Jennifer A
JA
Ray
Roberta M
RM
Lin
Ming Gang
MG
Gao
Dao Li
DL
Stalsberg
Helge
H
Feng
Ziding
Z
Thomas
David B
DB
Chen
Chu
C
D000328:Adult; D000368:Aged; D044466:Asian People / Q000235:genetics*; D001943:Breast Neoplasms / Q000235:genetics*; D016022:Case-Control Studies; D020420:Cyst Fluid; D047628:Estrogen Receptor alpha / Q000235:genetics*; D005260:Female; D005348:Fibrocystic Breast Disease / Q000235:genetics*; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D008875:Middle Aged; D011110:Polymorphism, Genetic / Q000235:genetics*; D011944:Receptors, Androgen / Q000235:genetics*; D012307:Risk Factors
C410798:AR protein, human; C506487:ESR1 protein, human; D047628:Estrogen Receptor alpha; D011944:Receptors, Androgen