• Low Z-4OHtam concentrations are associated with adverse clinical outcome among early stage premenopausal breast cancer patients treated with adjuvant tamoxifen 

      Helland, Thomas; Naume, Bjørn; Hustad, Steinar; Bifulco, Ersilia; Kvaløy, Jan Terje; Sætersdal, Anna Barbro; Synnestvedt, Marit; Lende, Tone Hoel; Gilje, Bjørnar; Mjaaland, Ingvil; Weyde, Kjetil; Blix, Egil Støre; Wiedswang, Gro; Borgen, Elin; Hertz, Daniel Louis; Janssen, Emiel; Mellgren, Gunnar; Søiland, Håvard (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-12-14)
      Abstract Low steady‐state levels of active tamoxifen metabolites have been associated with inferior treatment outcomes. In this retrospective analysis of 406 estrogen receptor‐positive breast cancer (BC) patients receiving adjuvant tamoxifen as initial treatment, we have associated our previously reported thresholds for the two active metabolites, Z‐endoxifen and Z‐4‐hydroxy‐tamoxifen (Z‐4OHtam), ...