Background: A cohort study for Caucasians aged 65 years or older demonstrated a marked breast cancer risk reduction for those with the CC genotype of transforming growth factor B1 (TGF B1) T29C polymorphism. This is a prevalent case-control study to examine the reported risk reduction for Japanese women.
Patients and methods: A total of 232 histologically diagnosed breast cancer patients who visited Aichi Cancer Center Hospital between June 1999 and March 2000 were enrolled. The controls were 172 female outpatients without cancer at the same hospital. DNA was extracted from peripheral blood, and TGF B1 genotype was determined by PCR-CTPP.
Results: The genotype frequency was 23.7% for TT, 49.2% for TC, and 27.1% for CC among controls, and 28.9%, 46.1%, and 25.0%, respectively, among cases. Age-adjusted odds ratio (OR) relative to the TT genotype was 0.81 (95% confidence interval, 0.50-1.31) for the TC genotype and 0.77 (0.45-1.34) for the CC genotype. For premenopausal women, the CC genotype was significantly associated with reduced risk of breast cancer in comparison with the TT genotype (OR=0.45, 0.20-0.98). The association was not observed for postmenopausal women (OR=1.40, 0.64-3.08).
Conclusion: The present study showed risk reduction for Japanese premenopausal women with the CC genotype, but not for postmenopausal Japanese women.