Polymorphic catechol-O-methyltransferase gene, duration of estrogen exposure, and breast cancer risk: a nested case-control study in Taiwan.
BACKGROUND
Polymorphic catechol-O-methyltransferase (COMT) catalyzes the O-methylation of catechol estrogens, which are hypothesized to participate in estrogen-induced carcinogenesis.


METHODS
We examined 87 cases and 341 population controls in Taiwan to determine the association between the functional genetic Val158Met polymorphism in membrane-bound form of COMT gene and female breast cancer risk. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by conditional logistic regression.


RESULTS
There was no overall association between COMT genotype and individual susceptibility to breast cancer. However, COMT-L variant genotypes appear to pose increased risk of breast cancer in women with greater duration from menarche to first full-term pregnancy (>8 years) (OR, 2.67; 95% CI, 1.00-7.36).


CONCLUSIONS
This study based on limited sample sizes suggests that there may be no overall association of COMT genotype with breast cancer, but the COMT-L allele could pose enhanced risk of breast cancer in the presence of relevant environmental exposures, as most low penetrance gene are expected to act through gene-environment interactions.
Lin
Wei-Yu
WY
School of Public Health, National Defense Medical Center, Taipei 114, Taiwan, Republic of China.
Chou
Yu-Ching
YC
Wu
Mei-Hsuan
MH
Jeng
Yi-Lin
YL
Huang
Han-Bin
HB
You
San-Lin
SL
Chu
Tang-Yuan
TY
Chen
Chien-Jen
CJ
Sun
Chien-An
CA
D000328:Adult; D001943:Breast Neoplasms / Q000209:etiology* / Q000235:genetics*; D016022:Case-Control Studies; D002394:Catechol O-Methyltransferase / Q000235:genetics / Q000378:metabolism; D004781:Environmental Exposure; D004967:Estrogens / Q000009:adverse effects*; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D008875:Middle Aged; D016017:Odds Ratio; D011110:Polymorphism, Genetic; D013624:Taiwan
D004967:Estrogens; D002394:Catechol O-Methyltransferase