The U.S. Preventive Services Task Force (USPSTF) is an independent national body of experts that develops guidelines using evidence-based medicine to improve the health of the population nationwide by finding and preventing progression of disease.
Current guidelines from 2016 directing recommendations for mammography are based on research involving cisgender women. Screening for cisgender women ages 40-49 years of age is targeted towards those with increased risk of breast cancer, including a family history of first degree relative, such as a parent, sibling or child. For the general population, the largest benefit is found when testing is completed every two years from 50 to 74 and may be altered based on shared decision making between patient and physician. These recommendations are being reviewed and are expected to be updated soon based on new research. As of May 9, 2023, the publicized rough draft of recommendations has expanded screening of the general population to as early as 40 or 45 and as late as 79. As such, many medical and research associations, including the American College of Radiology (ACR), have recommended screening starting at 40-45 years of age for the general population of cisgender women.
These breast cancer screening guidelines are developed based on large population studies that do not consider the diversity of gender non-conforming patients. Due to the paucity of large-scale studies and epidemiologic evidence, we are left to make screening decisions based on limited data. Currently, there are no strictly defined screening recommendations for breast cancer in the transgender patient population. An added complication in establishing screening guidelines for transgender women is the heterogenous delivery of gender-affirming therapy and individual hormone fluctuations. When considering lack of evidence combined with lack of education about transgender patients in our medical system, it is important to discuss breast cancer screening of this often-neglected population.
Breast tissue development typically peaks around 2-3 years following initiation of hormone therapy and contains breast ducts, lobules and acini. Transgender women receiving hormone therapy are subject to the same benign findings as cisgender women, such as cysts and fibroadenomas. Specifically, transgender women receiving hormone therapy for any length of time have shown development of denser breast tissue when compared to cisgender women. It is important to note that breast tissue development in transgender women is physiologically different from gynecomastia in cisgender men, as the latter results from hyperplasia of the ductal and stromal tissue.
Breast malignancies have been identified amongst transgender women, emphasizing the need for screening guidelines. The most comprehensive study done on breast cancer risk and hormone therapy in the transgender population was conducted in the Netherlands. It is important to note that many studies, including this one, may contain bias as population diversity is limited by a range of factors. It was found that transgender women receiving hormone treatment have a 46-fold higher risk of breast cancer than cisgender men. Still, breast cancer risk was lower than in cisgender women with an incidence ratio of 0.3. Additionally, breast cancer risk increased with the duration of hormone therapy, but this would not necessarily change screening recommendations. Overall, the breast cancer characteristics in transgender women were similar to that of cisgender women.
The risk of breast cancer in transgender women was previously thought to be greatest after 5 years of receiving hormone treatment, leading some physicians to initiate breast cancer screening in transgender women at the 5-year mark. However, hormone therapy regimens vary widely, as do hormone levels of individuals. These proposed guidelines also do not consider patients who stop taking hormone therapy for a variety of reasons, later to re-start their regimen. Breast development is also not one-size fits all, with peak breast density often reached before the 5-year mark. As such, the World Professional Association for Transgender Health (WPATH), the leading institution for transgender care worldwide, recommends screening transgender women per USPSTF breast cancer guidelines developed for cisgender women. This recommendation is also extended to other gender diverse people who were assigned female sex at birth who have retained natal breast tissue and are not receiving hormone therapy.
There are several considerations in deciding whether to screen annually versus every other year, and whether earlier screening is indicated. While tools such as the Gail Model from the National Institute of Health (NIH) can help decide on earlier or more frequent screening, they fail to include the transgender population in its algorithm. It is essential to discuss family history, smoking history, obesity, alcohol use and presence of breast prosthesis to make decisions with the patient. Testing for BRCA1 and BRCA2 should be considered in patients with strong family history of gynecological and breast cancers.
Transgender women who have undergone gender-affirming breast procedures should undergo mammogram screening per the guidelines discussed previously. While breast implants have not been found to increase rates of breast cancer, they may obstruct full visualization of breast tissue, leading to missed diagnoses. Implant-displaced views should be obtained to decrease the chances of missing a lesion. It is additionally important to identify the type of breast augmentation that was done. While illegal in the United States, there have been cases of injections of free substances, such as silicone, that pose their own unique subset of imaging difficulty and medical complications. Particle injection has the potential to result in sclerosing masses that may make tissue visualization difficult both on mammogram and ultrasound. Contrast-enhanced breast MRI is more sensitive in differentiating between benign granulomas and malignancy. Therefore, a detailed history of breast augmentation should be obtained to determine the optimal screening modality.
The evidence is equally lacking in general breast cancer screening guidelines in transgender men that have undergone top surgery. These individuals typically have subtotal mastectomies with residual breast tissue left in the axillary region to generate the aesthetic outcome of a contoured and masculine chest. Research reviewed by the ACR has generated recommendations using data derived from high-risk cisgender women after comparable surgeries who undergo prophylactic mastectomies. As such, it is presumed that transgender men have a similar risk of developing breast cancer, which is < 2%. The Netherlands study confirmed that transgender men receiving testosterone therapy are at a lower risk of developing breast cancer when compared to cisgender women. Again, WPATH recommends that transgender men follow the same guidelines as their cisgender peers in that those with significant family history be screened appropriately.
Transgender and gender-diverse individuals (TGD) have historically been marginalized socially and economically which has led to significantly greater health disparities compared to cisgender individuals. Health disparities include, but are not limited to, a lower prevalence of insurance, fewer socioeconomic resources to manage out-of-pocket medical expenses, increased chronic physical and mental health conditions often caused by minority stress, and discrimination in the health care setting. Lack of awareness, knowledge, sensitivity and bias from health care professionals leads to poorer health outcomes for this community.
Many TGD individuals have been mistreated or disrespected by health care staff in the past, causing fear, mistrust and reluctance to seek future care. To provide care that supports and affirms this population, health care professionals should have a better understanding of TGD individuals including their identities and communication needs. Tips to create a more affirming setting and practice for TGD individuals include:
- Collect information on the individual’s pronouns and chosen name, which may be different from the name on their insurance, medical records and identification documents. Use the correct name and pronouns, even when the individual is not present.
- Only ask questions necessary to a TGD individual’s care.
- Apologize when misgendering mistakes are made. Even after an apology, an individual may still have a negative reaction, so it’s important to remember that many TGD individuals have experienced discrimination, making it difficult to trust.
- Only discuss an individual’s TGD identity with those involved with providing care, which is consistent with privacy rules for all patients.
- Provide single occupancy “all gender” bathrooms.
- Provide training to all staff on culturally affirming communication and have policies in place to hold any staff accountable for discriminatory comments against TGD individual
In total, more research is needed to fully understand the risks of breast cancer in relation to various gender-affirming treatments across the spectrum of the population, including transgender, gender nonconforming, and otherwise gender diverse individuals. Breast cancer screening in the entire population is an essential part of providing good-quality care. Based on the information discussed in this article, the overall recommendation would be to treat transgender people the same as their cisgender counterparts. Currently, our best evidence lacks the diversity and nuances that impact the health outcomes of our transgender population. •
SOURCES:
- ACR Appropriateness Criteria® Transgender Breast Cancer Screening https://pubmed.ncbi.nlm.nih.gov/34794604/
- Affirmative Services for Transgender and Gender Diverse People- Best Practices for Frontline Health Care Staff https://www.lgbtqiahealtheducation.org/publication/affirmative-services-for-transgender-and-gender-diverse-people-best-practices-for-frontline-health-care-staff/
- Breast Imaging in Transgender Patients: What the Radiologist Should Know: https://pubs.rsna.org/doi/full/10.1148/rg.2020190044
- Breast Imaging of Transgender Individuals: A Review: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5773616/
- Breast cancer development in transsexual subjects receiving cross-sex hormone treatment https://pubmed.ncbi.nlm.nih.gov/24010586/
- Cancer screening in the transgender population: a review of current guidelines, best practices, and a proposed care model: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7807311/
- Health Care for Transgender and Gender Diverse Individuals https://www.acog.org/clinical/clinical-guidance/committee-opinion/articles/2021/03/health-care-for-transgender-and-gender-diverse-individuals
- Health and Health Care Access in the U.S. Transgender Population Health (TransPop) Survey https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8613303/
- Incidence of breast cancer in a cohort of 5,135 transgender veterans https://pubmed.ncbi.nlm.nih.gov/25428790/
- Patient-Friendly Summary of the ACR Appropriateness Criteria: Transgender Breast Cancer Screening: https://www.jacr.org/article/S1546-1440(21)00933-9/fulltext
- World Professional Association for Transgender Health: Standards of Care for the Health of Transgender and Gender Diverse People, Version 8. WPATH, 2022.
