Breast Cancer Screening for Transgender Adults

With nearly two million adults identifying as transgender in the United States, breast imaging guidelines are a topic of growing importance for radiologists.

“Breast cancer risk is low but present in transgender male and female patients, although current research may underrepresent the actual risk due to limited studies,” said presenter Rebecca Zhang, MD, diagnostic radiology resident at the University of Pennsylvania, Philadelphia. 

A 2019 Dutch study of 3,480 transgender patients reported four cases of invasive breast cancer among 1,229 transmasculine (female to male) patients and 18 cases (15 invasive) among 2,260 transfeminine (male to female) patients.  

To support health care providers and their transgender patients in clinical decision-making, Dr. Zhang compiled a case-based primer with appropriate-use criteria for transgender breast cancer screening. “The American College of Radiology provides guidelines, however, many are under-recognized and not as clear as those for cisgender patients,” she explained.

Dr. Zhang began by reviewing terms for this population, including transgender female (an individual assigned male at birth but who identifies her gender as female) and transgender male (an individual assigned female at birth who identifies his gender as male). 

“Diagnostic imaging for transgender patients largely mirrors guidelines for cisgender patients, with some nuanced differences in screening approaches,” she said. 

 

Recommended Screening Guidelines

According to Dr. Zhang, for all transgender patients, gender-affirming hormones, such as estrogen and testosterone, and gender-affirming surgeries have varying effects on the breasts and the risk of developing breast cancer. “For male-to-female patients, the most significant factor influencing screening is whether the patient has been taking gender-affirming hormones, particularly estrogen, for five or more years, which increases the risk of cancer,” she said

For people who have undergone estrogen therapy for five or more years, digital breast tomosynthesis (DBT)/mammography may be appropriate if they are 25 years old or older and at higher than average risk. It is also appropriate for people more than 40 years old and at average risk.

Dr. Zhang emphasized that patients who do not undergo estrogen therapy are not usually candidates for DBT or mammography, unless they are over 25 and at higher than average risk for breast cancer. US and MRI are not typically appropriate for transgender patients because of the potential for misdiagnosis and trauma from the procedures. “The guidelines aren’t official recommendations, but rather guidance to support the decision-making between the patient and their physician,” Dr. Zhang said. 

For female-to-male individuals, the delineating factor in breast screening is whether or not the patient has had bilateral mastectomies, or ‘top surgery.’ Dr. Zhang said for individuals who have not undergone mastectomy or have had a breast reduction, DBT/mammography, contrast-enhanced MRI and US may be appropriate for patients over age 25 and at high risk, and those older than 30 with an intermediate risk. For patients over the age of 40, the guidelines recommend DBT/mammography. 

For callback imaging and diagnostic workup for palpable masses, symptoms and implant-related symptoms, the guidelines parallel those for female cisgender patients. 

Dr. Zhang also described the post-treatment changes to the breast following hormonal and surgical therapies and shared a broad array of the most common breast screening scenarios encountered in transgender patients. “The transgender population is sizable in the U.S., and we want to make sure we’re giving them appropriate, tailored recommendations,” she said.

Access the presentation, “A Case-Based Primer on Breast Imaging in Transgender Patients,” (BREE-26) on demand RSNA.org/MeetingCentral.