Therapeutic Dose Monitoring (TDM) of Tamoxifen

Summary

Tamoxifen is a potent and effective drug reducing the risk of dying from breast cancer in the adjuvant setting. Although more modern drugs have partly replaced tamoxifen, it is helpful in the neoadjuvant and metastatic settings as a single drug. Despite that, in the adjuvant setting, it is a valuable drug. This study aims to validate and study the feasibility of serial assessments, including therapeutic drug monitoring of tamoxifen, 4-hydroxytamoxifen and Z-endoxifen by capillary blood sampling, combined with patient-reported symptom scores. This will provide preliminary data to allow us to develop a future multicentre randomised clinical trial of personalised dose monitoring and adjustment of adjuvant tamoxifen therapy to enhance the quality of life and breast cancer outcomes.

Timeline

Start

2022-04-04

Primary completion

2022-12-31

Completion

2023-03-01

Publications

• Background Early Breast Cancer Trialists' Collaborative Group (EBCTCG); Davies C, Godwin J, Gray R, Clarke M, Cutter D, Darby S, McGale P, Pan HC, Taylor C, Wang YC, Dowsett M, Ingle J, Peto R. Relevance of breast cancer hormone receptors and other factors to the efficacy of adjuvant tamoxifen: patient-level meta-analysis of randomised trials. Lancet. 2011 Aug 27;378(9793):771-84. doi: 10.1016/S0140-6736(11)60993-8. Epub 2011 Jul 28.
• Background Early Breast Cancer Trialists' Collaborative Group (EBCTCG). Aromatase inhibitors versus tamoxifen in early breast cancer: patient-level meta-analysis of the randomised trials. Lancet. 2015 Oct 3;386(10001):1341-1352. doi: 10.1016/S0140-6736(15)61074-1. Epub 2015 Jul 23.
• Background Eriksson M, Eklund M, Borgquist S, Hellgren R, Margolin S, Thoren L, Rosendahl A, Lang K, Tapia J, Backlund M, Discacciati A, Crippa A, Gabrielson M, Hammarstrom M, Wengstrom Y, Czene K, Hall P. Low-Dose Tamoxifen for Mammographic Density Reduction: A Randomized Controlled Trial. J Clin Oncol. 2021 Jun 10;39(17):1899-1908. doi: 10.1200/JCO.20.02598. Epub 2021 Mar 18.
• Background He W, Fang F, Varnum C, Eriksson M, Hall P, Czene K. Predictors of Discontinuation of Adjuvant Hormone Therapy in Patients With Breast Cancer. J Clin Oncol. 2015 Jul 10;33(20):2262-9. doi: 10.1200/JCO.2014.59.3673. Epub 2015 Jun 1.
• Background Madlensky L, Natarajan L, Tchu S, Pu M, Mortimer J, Flatt SW, Nikoloff DM, Hillman G, Fontecha MR, Lawrence HJ, Parker BA, Wu AH, Pierce JP. Tamoxifen metabolite concentrations, CYP2D6 genotype, and breast cancer outcomes. Clin Pharmacol Ther. 2011 May;89(5):718-25. doi: 10.1038/clpt.2011.32. Epub 2011 Mar 23.
• Background Fabian CJ. Will a Low-Dose Option Improve Uptake of Tamoxifen for Breast Cancer Risk Reduction? J Clin Oncol. 2019 Jul 1;37(19):1595-1597. doi: 10.1200/JCO.19.00656. Epub 2019 May 13. No abstract available.
• Background Smith SG, Sestak I, Forster A, Partridge A, Side L, Wolf MS, Horne R, Wardle J, Cuzick J. Factors affecting uptake and adherence to breast cancer chemoprevention: a systematic review and meta-analysis. Ann Oncol. 2016 Apr;27(4):575-90. doi: 10.1093/annonc/mdv590. Epub 2015 Dec 8.
• Background Thoren L, Lindh JD, Ackehed G, Kringen MK, Hall P, Bergh J, Molden E, Margolin S, Eliasson E. Impairment of endoxifen formation in tamoxifen-treated premenopausal breast cancer patients carrying reduced-function CYP2D6 alleles. Br J Clin Pharmacol. 2021 Mar;87(3):1243-1252. doi: 10.1111/bcp.14500. Epub 2020 Aug 9.
• Background Borges S, Desta Z, Li L, Skaar TC, Ward BA, Nguyen A, Jin Y, Storniolo AM, Nikoloff DM, Wu L, Hillman G, Hayes DF, Stearns V, Flockhart DA. Quantitative effect of CYP2D6 genotype and inhibitors on tamoxifen metabolism: implication for optimization of breast cancer treatment. Clin Pharmacol Ther. 2006 Jul;80(1):61-74. doi: 10.1016/j.clpt.2006.03.013.
• Background Jin Y, Desta Z, Stearns V, Ward B, Ho H, Lee KH, Skaar T, Storniolo AM, Li L, Araba A, Blanchard R, Nguyen A, Ullmer L, Hayden J, Lemler S, Weinshilboum RM, Rae JM, Hayes DF, Flockhart DA. CYP2D6 genotype, antidepressant use, and tamoxifen metabolism during adjuvant breast cancer treatment. J Natl Cancer Inst. 2005 Jan 5;97(1):30-9. doi: 10.1093/jnci/dji005.
• Background Ferraldeschi R, Newman WG. The Impact of CYP2D6 Genotyping on Tamoxifen Treatment. Pharmaceuticals (Basel). 2010 Apr 15;3(4):1122-1138. doi: 10.3390/ph3041122.
• Background Cronin-Fenton DP, Damkier P. Tamoxifen and CYP2D6: A Controversy in Pharmacogenetics. Adv Pharmacol. 2018;83:65-91. doi: 10.1016/bs.apha.2018.03.001. Epub 2018 May 7.
• Background Sanchez-Spitman AB, Swen JJ, Dezentje VO, Moes DJAR, Gelderblom H, Guchelaar HJ. Effect of CYP2C19 genotypes on tamoxifen metabolism and early-breast cancer relapse. Sci Rep. 2021 Jan 11;11(1):415. doi: 10.1038/s41598-020-79972-x.
• Background Bergqvist J, Lundstrom S, Wengstrom Y. Patient interactive digital support for women with adjuvant endocrine therapy in order to increase compliance and quality of life. Support Care Cancer. 2021 Jan;29(1):491-497. doi: 10.1007/s00520-020-05476-z. Epub 2020 May 13.

Drugs

Indications