Impact of cytochrome P450 2D6 polymorphisms on decision-making and clinical outcomes in adjuvant hormonal therapy for breast cancer.

Background: There are concerns that tamoxifen is less effective in Asian women because of the high prevalence of impaired function cytochrome P450 2D6 () polymor-phisms.

Aim: To evaluate how knowledge of genotype impacted the choice of hormonal agent and how genotype and agent were associated with clinical outcomes.

Methods: Eighty-two women were recruited.