Top Surgery and Cancer Risk

What do we know about breast cancer risk and top surgery?

Top surgery (gender-affirming mastectomy) reduces—but does not eliminate—breast cancer risk.

Subcutaneous mastectomies typically used in gender-affirming care leave some residual breast tissue (especially in the axillary tail or chest wall), unlike cancer risk-reducing mastectomies which aim to remove nearly all breast tissue (Stelios et al., 2018; Jatois & Kemp, 2021; Christine et al., 2024).

While longitudinal data remain limited, the most comprehensive study to date suggests that the incidence of breast cancer may be as high as 60x that of cisgender men and about 0.4x that of cisgender women (Corso et al., 2023). 

Clinical considerations for providers:

• Patients with family history of cancers associated with breast cancer risk should be assessed for genetic risk (see genetic risk page for more information). Ideally, this assessment should be offered prior to surgery to inform surgical decisions (NCCN). Risk assessment offered post surgically can inform future screening and surgical decisions.
• Patients with a family history of breast cancer or genetic variants (e.g., BRCA1/2, PALB2, CDH1, etc) may still be at high risk post-surgery.
• Discuss options for pathology review of removed tissue, potential for future screening, and referral to genetic specialists.
• Larger body habitus may result in retention of more fibroglandular tissue (Christine et al., 2024).
• Different top surgery techniques may result in variably retained tissue (Stelios et al., 2018).
  • Video depiction of surgical technique for a double-incision gender-affirming mastectomy.
  • Surgical video of double-incision gender-affirming mastectomy.
  • Video depiction of surgical techniques for a buttonhole or inverted T incision gender-affirming mastectomy.