What transgender women and transfeminine people need to know about breast cancer

Breast cancer screening may not be something you've thought about much if you were assigned male at birth, but it is possible for transfeminine people to develop breast cancer.

Until very recently, transfeminine people were often left out of breast cancer screening guidelines. But because the evidence indicates there is a risk, there has been an effort to develop more comprehensive guidelines. Here’s why it’s important to know your risk and to understand the recommendations for getting screened.

Knowing your breast cancer risk

People assigned male at birth in the United States have a 1 in 800 chance of being diagnosed with breast cancer at some point in their lives, according to data from the National Cancer Institute for the years 2015 to 2017. The risk for transfeminine people on gender-affirming hormone therapy (GAHT) is thought to be higher than that (though still lower than that of people assigned female at birth), based on a few factors. For starters, feminizing hormone therapy—which typically consists of estrogen along with testosterone-blocking medications—can lead to some breast growth.

"A transgender woman on hormone therapy develops breast tissue similar to a cisgender woman—the ducts and the lobules and parts of the breast that can be prone to breast cancer," says Ujas Parikh, MD, a radiologist at Cedars-Sinai in Los Angeles, California, and co-author of a 2019 article in the journal RadioGraphics on breast imaging in transgender patients. (Cisgender refers to a person whose gender identity corresponds with the sex they were identified as having at birth.)

While research on breast cancer risk in transfeminine people is limited, several existing studies do support the belief that it’s higher than the risk for cisgender men. Studies of postmenopausal cisgender women also link one type of hormone therapy—estrogen plus progestin—to increased risk. This finding could apply to transfeminine people on GAHT, explains Dr. Parikh.

Other risk factors for breast cancer also play a role, regardless of your gender. These include a personal or family history of breast or ovarian cancer, a genetic predisposition (or increased likelihood) to breast cancer, or a history of chest radiation.

Understanding the screening guidelines

In 2021, the American College of Radiology (ACR) published the first-ever ACR Appropriateness Criteria for Transgender Breast Cancer Screening. These guidelines offer recommendations based on a variety of factors, including age, hormone-therapy status, surgical history, and one’s unique risk factors. They advise when breast imaging is usually appropriate, may be appropriate, or usually not appropriate. Guidelines like these can give you a better idea of if and when you need to be screened and can help you have informed conversations with your healthcare provider (HCP).

For example, the ACR says that it may be appropriate for a transfeminine person who is 40 years or older and has been on hormone therapy for five or more years to get screened for breast cancer. The guidelines also suggest that it is usually appropriate to get screened if you are younger than that but have a higher-than-average risk due to your personal or family medical history.

As with general breast cancer screening guidelines, which tend to vary by the organization providing them, the recommendations for transgender people aren't necessarily unanimous. The University of California, San Francisco's Transgender Care and Treatment Guidelines, for example, recommend mammograms for transfeminine people every two years starting at age 50 and only after being on hormone therapy for five to 10 years.

As knowledge grows about the advantages of breast cancer screening in transfeminine people and researchers and medical associations continue making efforts to determine risks, guidelines are evolving. For now, the best thing you can do to navigate your own risk and screening is to have an open discussion of your risk factors and your hormone therapy with your HCP to determine the best plan for you.

“Despite the challenges of making recommendations, there has been increasing awareness of the importance of doing so," says Parikh, who cites the ACR’s guidelines for transgender individuals as an example of this trend.

Finding affirming care

People who are transgender, nonbinary, or gender nonconforming often face stigma and discrimination in healthcare settings, which can make the prospect of seeking a mammogram as a transfeminine person especially challenging. The good news is that if you already have an HCP who provides sensitive and affirming care to gender-diverse patients, they can often recommend other providers who will be similarly competent. Parikh suggests asking affirming providers for recommendations for radiology imaging centers that are also knowledgeable in transgender health care.

If you don't already have a trusted, affirming primary care provider, you can search for one through online resources like Outcare and GLMA, word of mouth, or local LGBTQ+ community resources. You can also call your local Planned Parenthood.

It's worth noting that if you're seeking breast cancer screening and your health insurance plan has your gender listed as male, you may need to ask your HCP for prior authorization or to use certain modifiers in order for screening to be covered. Making these phone calls before your appointment can save you time and stress in the event that your insurance company isn't cooperative.

"It's really exciting that we're trying to figure out the most effective and optimal ways to detect breast cancer in the transgender community," says Parikh. "I think there's still so much we need to do."