The incidence of invasive breast cancer among women prescribed testosterone for low libido

J Sex Med. 2009 Jul;6(7):1850-6. doi: 10.1111/j.1743-6109.2009.01289.x. Epub 2009 Apr 24.


Introduction: Although the efficacy of testosterone for the treatment of hypoactive sexual desire disorder is well established, the effect of testosterone therapy on breast cancer risk remains uncertain.

Aim: The incidence of invasive breast cancer among past and current testosterone users.

Methods: Retrospective cohort study of 631 women ever treated with testosterone between January 1989 and December 2007 in a clinical endocrinology practice.

Main outcome measure: The incidence of invasive breast cancer since first exposure, and the standardized incidence rate ratio (IRR) calculated using Australian age-specific incidence rates for 2005.

Results: The mean age of the women at first exposure to testosterone therapy was 49.1 +/- 8.2 years, median treatment duration, 1.3 years, and mean follow-up of 6.7 +/- 4.6 years, providing 4,015 woman-years of follow-up. Twelve cases of invasive breast cancer occurred among 599 women breast cancer-free before treatment, giving an age adjusted IRR of 1.35 (95% confidence interval 0.76-2.38). There was no evidence of an independent effect of duration of exposure on breast cancer risk.

Conclusion: In this study, testosterone use was not associated with a significant increase in breast cancer risk.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Androgens / administration & dosage
  • Androgens / adverse effects*
  • Androgens / therapeutic use
  • Australia / epidemiology
  • Breast Neoplasms / epidemiology*
  • Breast Neoplasms / etiology
  • Breast Neoplasms / pathology
  • Confidence Intervals
  • Female
  • Humans
  • Incidence
  • Middle Aged
  • Retrospective Studies
  • Risk Assessment
  • Sexual Dysfunctions, Psychological / drug therapy*
  • Testosterone / administration & dosage
  • Testosterone / adverse effects*
  • Testosterone / therapeutic use


  • Androgens
  • Testosterone