Breast Cancer Research and Treatment

, Volume 132, Issue 3, pp 1107–1118

Clinical and biomarker predictors of side effects from tamoxifen

Authors

    • Division of General Internal Medicine, Department of MedicineUniversity of California San Francisco
    • Division of Clinical Pharmacology and Experimental Therapeutics, Department of MedicineUniversity of California San Francisco
    • Helen Diller Family Comprehensive Cancer CenterUniversity of California San Francisco
    • UCSF Helen Diller Family Cancer Research Building
  • Alan H. B. Wu
    • Department of Laboratory MedicineUniversity of California San Francisco
    • San Francisco General Hospital
  • Mary S. Beattie
    • Division of General Internal Medicine, Department of MedicineUniversity of California San Francisco
    • Helen Diller Family Comprehensive Cancer CenterUniversity of California San Francisco
    • Department of Epidemiology and BiostatisticsUniversity of California San Francisco
    • Institute for Human GeneticsUniversity of California San Francisco
    • UCSF Medical Center at Mount Zion
  • Hope Rugo
    • Helen Diller Family Comprehensive Cancer CenterUniversity of California San Francisco
    • Division of Hematology and Oncology, Department of MedicineUniversity of California San Francisco
    • UCSF Medical Center at Mount Zion
  • Simone Tchu
    • Department of Biopharmaceutical SciencesUniversity of California San Francisco
    • San Francisco General Hospital
  • Karla Kerlikowske
    • Division of General Internal MedicineSan Francisco Veterans Affairs Medical Center
    • Department of Medicine and Epidemiology and BiostatisticsUniversity of California San Francisco
  • Elad Ziv
    • Division of General Internal Medicine, Department of MedicineUniversity of California San Francisco
    • Helen Diller Family Comprehensive Cancer CenterUniversity of California San Francisco
    • Department of Epidemiology and BiostatisticsUniversity of California San Francisco
    • Institute for Human GeneticsUniversity of California San Francisco
    • UCSF Helen Diller Family Cancer Research Building
Epidemiology

DOI: 10.1007/s10549-011-1893-4

Cite this article as:
Lorizio, W., Wu, A.H.B., Beattie, M.S. et al. Breast Cancer Res Treat (2012) 132: 1107. doi:10.1007/s10549-011-1893-4

Abstract

Tamoxifen decreases breast cancer recurrence, mortality, and breast cancer risk in high-risk women. Despite these proven benefits, tamoxifen use is often limited due to side effects. We identified predictors of tamoxifen-induced side effects based on clinical variables and serum tamoxifen metabolite biomarkers in a cross-sectional study of patients taking tamoxifen. We enrolled 241 women and collected data on demographics, tamoxifen use and side effects, as well as potential clinical and serum predictors. We used logistic regression models and adjusted for age, body mass index, ethnicity, education, prior post-menopausal hormone therapy (HT), tamoxifen duration, and endoxifen levels to identify factors associated with side effects. Common tamoxifen attributed side effects were hot flashes (64%), vaginal dryness (35%), sleep problems (36%), weight gain (6%), and depression, irritability or mood swings (6%). In multi-variate models, tamoxifen duration, age, prior post-menopausal HT, and endoxifen levels all predicted side effects. Women who had been on tamoxifen for >12 months were less likely to report side effects (OR 0.15, 95% CI 0.04–0.58) or severe side effects (OR 0.05, 95% CI 0.005–0.58) compared to women on tamoxifen for <12 months. Compared to women younger than 50, women who were age 60–70 and older than 70 were less likely to report side effects (OR 0.22, 95% CI 0.03–1.35; OR 0.13, 95% CI 0.01–0.99; respectively). Women who previously took post-menopausal HT were more likely to report severe side effects. Women with higher endoxifen levels were more likely to report side effects (OR 1.67, 95% CI 1.01–2.77 per standard deviation increase in endoxifen). Clinicians should consider closely monitoring adherence in women taking tamoxifen, especially in younger women, and women who previously took HT. The association between endoxifen levels and side effects is consistent with the data that suggest that endoxifen is the most highly active metabolite of tamoxifen.

Keywords

TamoxifenSide effectsPredictorsBiomarkersEndoxifenBreast cancer treatment

Copyright information

© Springer Science+Business Media, LLC. 2011