TGFB1 and TGFBR1 polymorphisms and breast cancer risk in the Nurses' Health Study

BACKGROUND: Transforming growth factor beta 1 (TGFB1) forms a signaling complex with transforming growth factor beta receptors 1 and 2 and has been described as both a tumor suppressor and tumor promoter. Single nucleotide polymorphisms in TGFB1 and a microsatellite in TGFBR1 have been investigated for association with risk of breast cancer, with conflicting results. METHODS: We examined polymorphisms in the promoter region of the TGFB1 gene as well as the TGFBR1*6A microsatellite in the Nurses' Health Study cohort. RESULTS: No overall associations between the L10P polymorphism of TGFB1 or the TGFBR1 microsatellite were detected. However, we observed an inverse association between the -509 C/T polymorphism of TGFB1 (p-trend = 0.04), which was stronger and more significant among women with estrogen receptor positive breast cancer. CONCLUSION: Polymorphisms in the promoter region of TGFB1 are not likely to be associated with large increases in breast cancer risk overall among Caucasian women.