p450 - publications
CYP2D6 and adjuvant tamoxifen: possible differences of outcome in pre- and post-menopausal patients.
Pharmacogenomics. 2013 Apr;14(6):613-22
Authors: Margolin S, Lindh JD, Thorén L, Xie H, Koukel L, Dahl ML, Eliasson E
Aim: Previous studies on CYP2D6 activity and the effect of adjuvant tamoxifen in breast cancer are inconsistent. We analyzed the impact of the CYP2D6 polymorphism in pre- and post-menopausal patients that were adherent to tamoxifen treatment for at least a year. Materials & methods: A total of 382 breast cancer patients prescribed adjuvant tamoxifen for 5 years constituted the study-base. Clinical information, including compliance and outcome, was retrieved from medical records. Comprehensive CYP2D6 genotyping was performed and translated into predicted metabolic activity. Results & conclusion: In patients adherent to tamoxifen for at least one year (n = 313) there was an association between reduced CYP2D6 activity (≤50% of normal) and recurrence (p = 0.025) and breast cancer-specific mortality (p = 0.034). In a multivariable analysis, CYP2D6 remained an independent predictor of outcome. In a subgroup analysis, the effect of CYP2D6 seemed to derive mainly from premenopausal patients, which represents a new finding that needs validation in a larger study sample. Original submitted 13 November 2012; Revision submitted 1 March 2013.
PMID: 23570465 [PubMed - in process]