Testosterone implants: 10-year data show a reduced incidence of breast cancer

  • Glaser RL & al.
  • BMC Cancer
  • 30 Dec 2019

  • curated by Miriam Davis, PhD
  • Univadis Clinical Summaries
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Takeaway

  • Testosterone implants are associated with a reduced incidence of breast cancer, according to 10-year results from the prospective cohort Dayton study.

Why this matters

  • For more than 80 years, women with hormone deficiency have been treated with testosterone implants.
  • Findings should be reassuring to female testosterone recipients.
  • Findings may spur research on testosterone implants for breast cancer prevention.

Study design

  • A prospective cohort of pre- and postmenopausal women (N=1267) given at least 2 subcutaneous pellet insertions of testosterone (2-2.5 mg/kg starting dose) for hormone deficiency.
  • 21.1% of women received testosterone plus anastrozole.
  • Breast cancer incidence was studied within 240 days of last testosterone insertion.
  • Funding: None.

Key results

  • 11 cases of breast cancer were observed (vs 18 expected) among recipients of testosterone and testosterone/anastrozole, an incidence rate of 165/100,000 person-years.
  • This incidence rate is 39% lower than the age-matched Surveillance Epidemiology and End Results expected incidence rate of 271/100,000 person-years (P<.001>
  • The breast cancer incidence rate among recipients was also lower than historical controls.

Limitations

  • Observational design.
  • Lack of a matched control group.