The Confusing World of Breast Cancer Screening for Transgender People

Cisgender women are easily the largest gender demographic affected by breast cancer, but transgender men, trans women, and non-binary people (along with cisgender men) can also develop the disease. When it comes to screening and early detection, however, transgender and non-binary people are almost totally out of the picture. Although screening guidelines for cisgender women are frequently changing and can be difficult to follow, the situation is even worse for transgender and non-binary people. Guidelines do exist specifically for transgender people, but because the data backing them is scarce, the recommendations are not well known — even among doctors — and differ dramatically between sources.

The screening guidelines for transgender men and non-binary people who are assigned female at birth (afab) are largely based on the guidelines for cisgender women, but  the impact of top surgery on the need for breast cancer screening is debated among physicians. Guidance for transgender women and non-binary people who are assigned male at birth (amab) are based on even less data and are mostly influenced by length of time on estrogen, which can increase breast cancer risk. 

The major guidelines for breast cancer screening for transgender people come from the American College of Radiology (ACR), the United States Preventive Services Task Force (USPSTF), the World Professional Association for Transgender Health (WPATH), the Endocrine Society, and the UCSF Center of Excellence for Transgender Health (which has recommendations for both trans men and trans women). But these guidelines are, in several cases, just a few sentences in a much larger document about transgender healthcare. The ACR provides the most comprehensive and detailed guidelines. 

For amab non-binary and trans women, the ACR recommends the following:

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  If less than 5 years of hormone use and average risk, no testing

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  If less than 5 years of hormone use, 25 to 30 years or older, and higher-than-average risk, annual digital breast tomosynthesis (DBT, also called a 3D mammogram) or mammogram “may be appropriate” 

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  If 5 or more years of hormone use, 25 to 30 years or older, and higher-than-average risk, annual DBT or mammogram is “usually appropriate” 

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  If 5 or more years of hormone use, 40 years or older, and average risk, annual DBT or mammogram “may be appropriate”

Some of these recommendations differ from those made by the other organizations. For example, UCSF recommends mammograms every other year starting at age 50 for transfeminine people who have been on hormones for at least five years and are at average risk, and does not offer guidance for those at above-average risk. The Endocrine Society and WPATH simply recommend that transgender women follow the guidelines for cisgender women.

“I think starting at 50 is a very conservative way of thinking, and you're going to miss, obviously, some breast cancers in women that are 40 to 50,” says Stamatia Destounis, MD, FACR, chair of the American College of Radiology Breast Imaging Commission. This is true, she says, for both cisgender women and transgender patients. “We want to find every cancer that's there. We want to find them as early as possible because that's the best prognosis for the patient.” Other organizations that recommend starting later, for both cisgender and transgender people, place more of an emphasis on reducing callbacks, unnecessary biopsies, anxiety for patients, and healthcare costs, she adds.

For afab non-binary people and trans men, the ACR recommends the following:

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  If you have had top surgery, no testing

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  If you have not had top surgery or you’ve had only a reduction, are 40 years or older, and have average risk, DBT or mammogram is “usually appropriate”

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  If you have not had top surgery or you’ve had only a reduction, are 30 years or older, and have intermediate risk, DBT or mammogram is “usually appropriate,” and breast MRI with and without intravenous contrast “may be appropriate”

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  If you have not had top surgery or you’ve had only a reduction, are 25 to 30 years or older, and have high risk, DBT, mammogram, and breast MRI with and without intravenous contrast “is usually appropriate”

Unlike the ACR, other organizations do not recommend skipping testing for trans people who have had top surgery. Rather, WPATH and UCSF encourage dialogue and shared decision-making regarding testing. UCSF also states that, because there isn't enough breast tissue for a mammogram, alternatives such as ultrasound or MRI may be necessary. The USPSTF states that transmasculine individuals should follow the guidelines for cisgender women, and the Endocrine Society guidelines don’t address breast cancer risk for trans men at all.

Many experts in the field disagree with the ACR recommendation against breast cancer screening for transgender men who have undergone top surgery. “There absolutely is consensus that anybody who has top surgery is still at risk for breast cancer, because breast tissue is left in shaping the chest. That's different than mastectomy, where the breast tissue is all removed for cancer risk,” says Scout, MA, PhD, executive director of the National LGBT Cancer Network (Scout has only one name). The ACR’s guidance is in direct conflict with that consensus and with the best available data on breast cancer in trans men.

The above guidelines are all evidence-based. This is normally a good thing because it means recommendations are based on real-world data. But here it illustrates not only that different expert organizations have different interpretations of the available data, but also that there is very little data available to begin with.

“We don't have a lot of outcome data, so it's hard to come up with these guidelines that are perfectly inclusive and perfectly correct,” Destounis says.

Very little research has investigated how breast cancer risk differs for transgender people in comparison to cisgender women and men. One of the largest studies on this topic, which included 2,260 trans women and 1,229 trans men who received gender-affirming hormone treatment in the Netherlands, found 15 cases of invasive breast cancer in the trans women and four in the trans men. The breast cancer risk for trans women was 46-fold higher than for cis men — though still much lower than that of cisgender women — and the cancers found in trans women were more similar to those found in cis women than in cis men. The risk for the trans men, meanwhile, was five times lower than for cis women. Overall, the breast cancer risk for cisgender women appears to be highest, followed by transgender people, followed by cisgender men. This is just one study, so it cannot determine the true breast cancer risk for trans people. However, it is the best data available.

Breast cancer screening guidelines for transmasculine people don’t take into account the effects of testosterone therapy, which may affect the risk of developing estrogen receptor-positive breast cancer. Similarly, the guidelines for transfeminine people do not consider bottom surgery — and thus whether they’re still producing testosterone. Future research should take into account factors such as these. “If you've changed something, a big piece of a complicated system,” says Scout, “it probably affects all the other systems.”

The main reason we lack data on breast cancer risk for trans folks is that medical systems historically weren’t set up to track whether a person is transgender. And if researchers don’t have data on trans people, then they’re not able to determine their breast cancer risk and under what circumstances screening is most beneficial.

“For a very, very long time, gender identity was not collected,” says Sumanas Jordan, MD, PhD, a plastic surgeon at Northwestern Medicine who splits her time between reconstructive breast surgery and gender-affirming surgery. But this situation is improving. “In the past five years, there's been a strong push among some of the major electronic medical health record systems to build that into their programming.” Oncologists with a research niche in LGBTQ health have also been working to add data on sexual orientation and gender identity (SOGI) to state and national cancer databases.

But because there isn’t data available on breast cancer mortality in trans people, it’s difficult to get funding for cancer research on this population, Scout says. “The way we get research funded is by having evidence of a disparity in the first place. And the data for trans and non-binary and gender-nonconforming people are so thoroughly suppressed by the health system right now that we don't have any outcome information,” they say. “We only have risk information from the surveys of people who are alive.”

Procuring more data to enhance the screening guidelines for transgender people will only solve part of the problem, however. Having adequate guidance doesn’t do much if trans people aren’t adhering to it — and right now, they’re largely not.

A 2021 study from Northwestern Medicine, for example, found that only 1.7% of afab trans people had a mammogram within two years of age 40, as recommended by the American Society of Breast Surgeons and other organizations, and only 13.3% within two years of age 50. Only 7.1% of amab trans people who had been on estrogen for at least five years were tested within two years of age 50, which is the recommended screening age of the least cautious guidelines. In comparison, 74.1% of cisgender women adhere to screening recommendations, according to the National Cancer Institute.

One reason for the trans population’s low adherence to screening guidelines is that many providers aren’t aware of them. A 2023 study that surveyed 95 primary care providers found that only 35% were aware that breast cancer screening guidelines for trans people existed. And if they’re unaware, that means they’re unable to encourage their trans patients to follow the guidance.

Additionally, many electronic medical systems aren’t set up to flag trans patients as needing breast cancer screening. And trans men and afab non-binary people may be reluctant to get breast cancer screening because of gender dysphoria related to their chest or going to a women’s health center for their screening, where they may be misgendered or discriminated against for their masculine appearance. And the phrase “breast cancer” itself may be alienating to transmasculine people due to its gendered connotation.

Even getting a trans person to find a primary care provider who could flag them as someone who needs breast cancer screening is difficult because medical mistrust is widespread in the trans community; trans people fear being discriminated against by doctors and their staff. If they do see a doctor, trans people who have had top surgery may not reveal that they’re trans, and so their doctors may not know to recommend breast cancer screening. This issue also worsens the data-gathering problem: If trans people don’t reveal that they’re trans to their doctors, then they can’t be included in studies about breast cancer in trans people.

“I can't even in a very, very welcoming state, figure out if those people are going to treat me with dignity,” says Scout, who is trans themself, about seeing new medical providers. “Even when there's good guidelines, that doesn't mean that you've suddenly jumped over the barrier for medical mistrust. It still exists. And it's really warranted in our communities.”