Therapeutic Drug Monitoring of endoxifen as an alternative for CYP2D6 genotyping in individualizing tamoxifen therapy

Aurelia H M de Vries Schultink; Alwin D R Huitema; Jos H Beijnen

doi:10.1016/j.breast.2018.08.100

Therapeutic Drug Monitoring of endoxifen as an alternative for CYP2D6 genotyping in individualizing tamoxifen therapy

Breast. 2018 Dec:42:38-40. doi: 10.1016/j.breast.2018.08.100. Epub 2018 Aug 22.

Authors

Aurelia H M de Vries Schultink¹, Alwin D R Huitema², Jos H Beijnen³

Affiliations

¹ Department of Pharmacy & Pharmacology, Antoni van Leeuwenhoek - The Netherlands Cancer Institute and MC Slotervaart, Louwesweg 6, 1066 EC Amsterdam, The Netherlands. Electronic address: [email protected].
² Department of Pharmacy & Pharmacology, Antoni van Leeuwenhoek - The Netherlands Cancer Institute and MC Slotervaart, Louwesweg 6, 1066 EC Amsterdam, The Netherlands; Department of Clinical Pharmacy, University Medical Center Utrecht, Utrecht University, P.O. Box 85500, 3508 GA, Utrecht, The Netherlands.
³ Department of Pharmacy & Pharmacology, Antoni van Leeuwenhoek - The Netherlands Cancer Institute and MC Slotervaart, Louwesweg 6, 1066 EC Amsterdam, The Netherlands; Science Faculty, Utrecht Institute for Pharmaceutical Sciences (UIPS), Division of Pharmacoepidemiology & Clinical Pharmacology, Utrecht University, P.O. Box 80082, 3508 TB Utrecht, The Netherlands.

PMID: 30153552
DOI: 10.1016/j.breast.2018.08.100

Abstract

Different strategies have been proposed to individualize tamoxifen treatment in order to improve recurrence-free survival in estrogen receptor (ER)-positive breast cancer. To date, the debate remains on which strategy should be used. The objective of this viewpoint is to highlight Therapeutic Drug Monitoring of endoxifen, the active tamoxifen metabolite, as the preferred methodology compared to CYP2D6 genotyping for individualizing tamoxifen therapy for ER-positive breast cancer patients treated in the adjuvant setting.

Keywords: Endoxifen; Therapeutic Drug Monitoring; Treatment individualization.

MeSH terms

Antineoplastic Agents, Hormonal / therapeutic use*
Breast Neoplasms / drug therapy*
Breast Neoplasms / genetics*
Cytochrome P-450 CYP2D6 / genetics
Female
Genotype
Humans
Precision Medicine / methods*
Tamoxifen / analogs & derivatives*
Tamoxifen / therapeutic use

Substances

Antineoplastic Agents, Hormonal
Tamoxifen
4-hydroxy-N-desmethyltamoxifen
Cytochrome P-450 CYP2D6