title: Highly sensitive simultaneous quantification of estrogenic tamoxifen metabolites and steroid hormones by LC-MS/MS.
abstract: Tamoxifen is a mainstay in the treatment of estrogen receptor-positive breast cancer and is metabolized to more than 30 different compounds. Little is known about in vivo concentrations of estrogenic metabolites E-metabolite E, Z-metabolite E, and bisphenol and their relevance for tamoxifen efficacy. Therefore, we developed a highly sensitive HPLC-ESI-MS/MS quantification method for tamoxifen metabolites bisphenol, E-metabolite E, and Z-metabolite E as well as for the sex steroid hormones estradiol, estrone, testosterone, androstenedione, and progesterone. Plasma samples were subjected to protein precipitation followed by solid phase extraction. Upon derivatization with 3-[(N-succinimide-1-yl)oxycarbonyl]-1-methylpyridinium iodide, all analytes were separated on a sub-2-μm column with a gradient of acetonitrile in water with 0.1 % of formic acid. Analytes were detected on a triple-quadrupole mass spectrometer with positive electrospray ionization in the multiple reaction monitoring mode. Our method demonstrated high sensitivity, accuracy, and precision. The lower limits of quantification were 12, 8, and 25 pM for bisphenol, E-metabolite E, and Z-metabolite E, respectively, and 4 pM for estradiol and estrogen, 50 pM for testosterone and androstenedione, and 25 pM for progesterone. The method was applied to plasma samples of postmenopausal patients taken at baseline and under tamoxifen therapy. Graphical Abstract Sample preparation and derivatization for highly sensitive quantification of estrogenic tamoxifen metabolites and steroid hormones by HPLC-MS/MS.
authors.affiliation: Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Auerbachstr. 112, 70376, Stuttgart, Germany.|University of Tübingen, 72076, Tübingen, Germany.
authors.forename: Janina
authors.initials: J
authors.lastname: Johänning
authors.affiliation: Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Auerbachstr. 112, 70376, Stuttgart, Germany.|University of Tübingen, 72076, Tübingen, Germany.
authors.forename: Georg
authors.initials: G
authors.lastname: Heinkele
authors.affiliation: Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Auerbachstr. 112, 70376, Stuttgart, Germany.|University of Tübingen, 72076, Tübingen, Germany.
authors.forename: Jana C
authors.initials: JC
authors.lastname: Precht
authors.affiliation: Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Auerbachstr. 112, 70376, Stuttgart, Germany.|University of Tübingen, 72076, Tübingen, Germany.|German Cancer Consortium (DKTK) and German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany.
authors.forename: Hiltrud
authors.initials: H
authors.lastname: Brauch
authors.affiliation: Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Auerbachstr. 112, 70376, Stuttgart, Germany.|University of Tübingen, 72076, Tübingen, Germany.
authors.forename: Michel
authors.initials: M
authors.lastname: Eichelbaum
authors.affiliation: Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Auerbachstr. 112, 70376, Stuttgart, Germany.|University of Tübingen, 72076, Tübingen, Germany.|German Cancer Consortium (DKTK) and German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120, Heidelberg, Germany.|Department of Clinical Pharmacology, Institute of Experimental and Clinical Pharmacology, University Hospital, Auf der Morgenstelle 8, 72076, Tübingen, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Schwab
authors.affiliation: Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Auerbachstr. 112, 70376, Stuttgart, Germany.|University of Tübingen, 72076, Tübingen, Germany.
authors.forename: Werner
authors.initials: W
authors.lastname: Schroth
authors.affiliation: Dr. Margarete Fischer-Bosch-Institute of Clinical Pharmacology, Auerbachstr. 112, 70376, Stuttgart, Germany. thomas.muerdter@ikp-stuttgart.de.|University of Tübingen, 72076, Tübingen, Germany. thomas.muerdter@ikp-stuttgart.de.
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Mürdter
mesh_terms: D018931:Antineoplastic Agents, Hormonal / Q000097:blood*; D001943:Breast Neoplasms / Q000097:blood*; D002853:Chromatography, Liquid / Q000379:methods*; D005260:Female; D006801:Humans; D057230:Limit of Detection; D017698:Postmenopause; D013629:Tamoxifen / Q000378:metabolism*; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D018931:Antineoplastic Agents, Hormonal; D013629:Tamoxifen
keywords: Derivatization; LC-MS/MS; Plasma; Steroid hormones; Tamoxifen metabolites