What are the mammography screening recommendations for transitioning individuals on hormone therapy, specifically those on estrogen and anti-androgen therapies?

Mammography Screening Recommendations for Transgender Individuals on Hormone Therapy

Transgender women who have been on feminizing hormone therapy (estrogen and anti-androgens) for 5 or more years should undergo screening mammography starting at age 50, with annual or biennial screening depending on additional risk factors. 1, 2

Risk Assessment for Transgender Women

• Transgender women on hormone therapy have significantly increased breast cancer risk compared to cisgender men:

  • Incidence of approximately 31.4 per 100,000 person-years in transgender women on HRT 2
  • 46.7 times higher risk than cisgender men (SIR: 46.7,95% CI: 27.2-75.4) 1, 2
  • Still lower than cisgender women (170 per 100,000 person-years) 2

• Risk increases with duration of hormone exposure:

  • Significant increases noted after a median of 18 years (range 7-37 years) 1, 2
  • 5 years is the established threshold for initiating screening 1, 2

Screening Protocol for Transgender Women

Standard Risk Transgender Women

• Duration of hormone therapy < 5 years:

  • No screening necessary 1

• Duration of hormone therapy ≥ 5 years:

  • Begin screening at age 50 1, 2
  • Frequency: Every 1-2 years (annual per Fenway Health, biennial per UCSF Center) 1
  • Preferred modality: Digital mammography or digital breast tomosynthesis (DBT) 1, 2

Higher Risk Transgender Women

• Begin screening earlier if any of the following risk factors are present 1, 2:
  • Personal history of breast cancer
  • Chest radiation between ages 10-30
  • Genetic predisposition (BRCA mutations)
  • Family history of breast/ovarian cancer
  • Screen 10 years earlier than the age at diagnosis of affected relative (not before age 30)

Clinical Considerations

• Breast tissue in transgender women is histologically identical to cisgender female breast tissue and should not be referred to as gynecomastia 2

• Hormone therapy affects mammographic density:

  • Increased density can reduce both sensitivity (7-21%) and specificity (12-50%) of mammography 3, 4
  • Consider temporary cessation of HRT for 3-6 months before repeat mammography if initial results are unclear 4

• MRI with contrast has limited use, primarily for patients who have undergone direct injection of particles for breast augmentation 1

• Ultrasound has insufficient evidence to support routine screening 1

Common Pitfalls to Avoid

1. Assuming transgender women have the same breast cancer risk as cisgender women (their risk is intermediate) 2

2. Failing to account for duration of hormone therapy when determining screening protocols 1, 2

3. Overlooking additional risk factors that may necessitate earlier or more frequent screening 1, 2

4. Neglecting the impact of hormone therapy on mammographic density and interpretation 3, 4

5. Using inappropriate terminology when discussing breast tissue with transgender patients 2

6. Failing to provide culturally competent care, as studies show 50% of transgender patients report having to teach providers about transgender healthcare, and 19% report being denied care due to discrimination 1