Article: Breast cancer risk for transgender women with inherited mutations
Most relevant for: Transgender women with inherited mutations who are considering or have had gender affirming care. It may also be relevant for:
- people with a genetic mutation linked to cancer risk
- transgender people
What is this study about?
Very little research has been done to understand the breast cancer risk of transgender women who have an linked to breast cancer risk. For this reason, it is not well known how gender-affirming medical care (such as hormone therapy and surgery) may impact risk.
This XRAY review summarizes what is known and highlights what is missing for transgender women with inherited mutations that increase breast cancer risk.
Unique challenges and unanswered questions
Transgender women may choose to take medications, including hormone therapy, or have surgeries to reflect their gender. Some of these gender-affirming treatments may affect breast cancer risk. The lack of research on breast cancer risk and health outcomes for high-risk transgender women limits experts’ ability to make risk-management recommendations.
How genetic testing can help assess risk
For transgender women with a family history of breast cancer or a known family mutation, genetic counseling and testing can help inform their decisions about . While genetic testing for inherited mutations linked to adult-onset cancers is not typically offered to minors, genetic testing for transgender patients may affect their decisions related to gender-affirming hormone therapy, such as puberty blocker.
Breast cancer risk
Tools used to calculate breast cancer risk are based on research from people (people who identify with the gender that was assigned to them at birth). These tools have not been tested on transgender individuals, which means they may or may not be accurate for them.
Evidence relating to breast cancer in the trans population is limited. There is not enough data to estimate risk. Even less data is available on how to estimate the risk for a transgender person with a family of breast cancer or a known gene mutation.
People who are assigned male at birth typically have a low lifetime risk for breast cancer. However, inheriting a mutation in any of the genes listed below is linked to an increased risk for male breast cancer and breast cancer in people assigned male at birth. Transgender women who have an increased breast cancer risk due to an may want to consider increased breast screening or risk-reducing mastectomies (removal of their at-risk breast tissue) with or without reconstruction if they are considering gender-affirming surgery such as breast augmentation or hormonal therapy that could increase breast tissue.
Genes linked to increased risk for people assigned male at birth include:
Gender-affirming care for transgender women may include the use of the hormone with or without , as well as hormones to decrease testosterone.
Long-term exposure to is a well-known risk factor for breast cancer in women. Since transgender women may use for a long period (sometimes for the rest of their lives) or at higher doses than women, there is concern that this may increase their risk for breast cancer.
The most complete study of breast cancer risk relative to the use of hormone therapy for transgender women with no linked to cancer found that the lifetime risk for breast cancer among transgender women who had short or long-term hormone therapy is greater than men. The risk was similar to or lower than the risk among women. It is important to note that the study did not look at how hormone therapy may impact breast cancer risk among transgender women with an .
This highlights an important research gap and the need to better understand how gender-affirming hormone therapy impacts breast cancer risk for transgender women with an .
Despite this gap, the National Comprehensive Cancer Network (NCCN), a panel of experts that creates health guidelines, added a new section to their 2024 guidelines for risk management of transgender women at high risk for breast cancer. While the NCCN acknowledges the lack of relevant research, it considers hormones used for to be acceptable for high-risk transgender women.
How to best image and screen for breast cancer depends on the type of treatment, if any, transgender women have had. may include breast augmentation or breast enlargement injections (the latter are prohibited in the United States, but are available in other countries). Numerous professional organizations, such as the American College of Radiology, provide guidelines for breast cancer screening of transgender women.
For men with a , or mutation, clinical breast exams and self-exams are recommended beginning at age 35. The guidelines also recommend considering beginning annual mammograms (especially for men with mutations) beginning around age 50. However, there are no specific guidelines for when, how or how often transgender women with an inherited , or mutation should undergo breast cancer screening. Nor do specific breast screening guidelines exist for transgender women with mutations in other genes who take hormones as part of their .
The 2024 NCCN guidelines update acknowledges the lack of research in this area but supports the idea of breast screening using and/or mammograms for high-risk transgender women.
In the absence of more specific guidelines, transgender women with an that increases breast cancer risk should try to find a healthcare team that is knowledgeable in transgender care and risk management for people with inherited mutations. These experts may often be found at larger medical centers.
What does this mean for me?
If you are a transgender woman with an increased risk of breast cancer due to an , try to find a healthcare system that has expertise in transgender care and cancer genetics. Talk with your healthcare team about your risk for breast cancer, the benefits and risks of different types of screenings and risk reduction options. These may differ based on the you receive.
Sutherland N, Espinel W, Grotzke M, Colonna S. Unanswered Questions: Hereditary breast and gynecological cancer risk assessment in transgender adolescents and young adults. J Genet Couns. 2020; 29:625–633.
Clarke CN, Cortina CS, Fayanju OM, Dossett LA, Johnston FM, Wong SL. Breast Cancer Risk and Screening in Transgender Persons: A Call for Inclusive Care. Ann Surg Oncol. 2022;29(4):2176-2180.
Lienhoop T, Green L. Breast imaging in transgender women: a review. Clin Imaging. 2021;80:283-289.
Disclosure: FORCE receives funding from industry sponsors, including companies that manufacture cancer drugs, tests and devices. All XRAYS articles are written independently of any sponsor and are reviewed by members of our Scientific Advisory Board prior to publication to assure scientific integrity.
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Mutations in several genes increase the risk for breast/chest cancer, including , , , , , , , , , , , , and . Risk-reducing strategies differ by biological sex at birth.
Female sex assignment at birth
- Hormones: It is unknown whether gender-affirming testosterone therapy changes the risk of breast cancer.
- Genetic testing: For people with a personal or family history consistent with , the NCCN recommends genetic testing before breast/chest surgery to inform the type of surgery.
- Surgery: Gender-affirming surgery, known as “top surgery,” involves removing some but typically not all breast tissue. People with an in a breast cancer gene may want to consider removing more tissue than top surgery typically does, like a risk-reducing mastectomy, that removes more than 95% of breast tissue. Nipple-sparing surgery can be safe but the resulting appearance may not be as good as top surgery, which retains some breast tissue. Transmen may want to discuss their chest profile options with a plastic surgeon.
- Screening: For transgender men with an (those who have had top surgery or no breast surgery), the NCCN recommends breast cancer screening may begin at an earlier age and may include and breast . Discuss gene-specific screening recommendations with your provider.
Male sex assignment at birth
- Hormones: Estrogens and anti-androgen hormone therapy increase breast tissue. Breast cancer among people receiving this therapy can develop at an earlier age than in the average population. However, even with an , breast cancer risk in people who were assigned male sex at birth is low, so while and anti-androgens may increase breast cancer risk, these hormones can be used.
- Screening: Because little is known about the benefit of chest/breast cancer screening for transgender women, it should be decided on a case-by-case basis, based on a person’s age, family history, duration of gender-affirming hormone therapy and the amount of breast tissue. For imaging, and are recommended rather than . without contrast can help monitor silicone breast implants for leaks but it does not detect cancer.
The following organizations offer peer support services for people from the LGBTQ+ community.
- FORCE holds virtual support meetings organized by and for members of the LGBTQ+ community. Check our National Meetings page for the next scheduled meeting.
- The National LGBT Cancer Network offers cancer support group meetings.
The following resources can help people from the LGBTQ+ community find compassionate care.
Finding LGBTQ+-friendly care
- National LGBTQ Cancer Network Database of LGBTQ+-Welcoming Cancer Screening Providers
- National LGBTQ Cancer Network Database of LGBTQ+-Welcoming Cancer Treatment Providers
Other ways to find experts
- Register for the FORCE Message Boards and post on the Find a Specialist board to connect with other people who share your situation.
- The National Cancer Institute (NCI)-designated comprehensive cancer centers provide cutting-edge cancer care. They receive funding from the National Cancer Institute to provide community outreach and inclusive care.