Abstract
Tamoxifen has been widely used for the prevention of recurrence in patients with hormone receptor-positive breast cancer. Tamoxifen requires metabolic activation by cytochrome P450 (CYP) enzymes for formation of active metabolites, 4-hydroxytamoxifen and endoxifen, which have 30- to 100-fold greater affinity to the estrogen receptor and the potency to suppress estrogen-dependent breast cancer cell proliferation. CYP2D6 is a key enzyme in this metabolic activation and it has been suggested that the genetic polymorphisms of CYP2D6 influence the plasma concentrations of active tamoxifen metabolites and clinical outcomes for breast cancer patients treated with tamoxifen. The genetic polymorphisms in the other drug-metabolizing enzymes, including other CYP isoforms, sulfotransferases and UDP-glucuronosyltransferases might contribute to individual differences in the tamoxifen metabolism and clinical outcome of tamoxifen therapy although their contributions would be small. Recently, involvement of a drug transporter in the disposition of active tamoxifen metabolites was identified. The genetic polymorphisms of transporter genes have the potential to improve the prediction of clinical outcome for the treatment of hormone receptor-positive breast cancer. This review summarizes current knowledge on the roles of polymorphisms in the drug-metabolizing enzymes and transporters in tamoxifen pharmacogenomics.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.