Breast Cancer Risk Management in Transgender Men After Chest Contouring Surgery

Transgender men are in need of specific guidelines for breast cancer detection. | Image Credit/ Rawpixel.com - stock.adobe.com

A risk management approach is suggested for breast cancer detection in transgender men following chest contouring mastectomy, according to a study published in PLOS ONE. However, further education between patients and physicians is significant, while including patient decision making in the process.¹

Chest contouring surgery, informally known as “top” surgery, is a plastic surgery procedure that shapes the skin and tissue of the chest to represent the contour of a male chest.² This gender-affirming procedure allows transgender men to align their physical bodies to their gender identity, reducing cases of gender dysphoria.³

Gender dysphoria, as defined by the American Psychiatric Association, is psychological distress that causes incongruence between an individual’s assigned sex at birth and their gender identity.⁴ Approximately three-quarters of transgender people experience gender dysphoria by the age of 7 years.⁵

According to the Global Cancer Observatory, breast cancer affects an estimated 47.8% of some 100,000 cisgender women.⁶ However, transgender male populations carry risk of breast cancer but current knowledge of the outcomes of procedures for both pre and post-operations are unknown.¹

Evaluating Breast Cancer Risk in Trans Men

The systemic literature search began on March 14, 2023, and researchers applied the Swiss cheese model of risk analysis to illustrate how hazards can develop into an accident. For this study, the model displayed the hazard of breast cancer among transgender men, specific preventative factors, and any identifiable weaknesses in the prevention methods.

Cases of Breast Cancer in Trans Men

After exclusion criteria, a total of 22 articles were included in the review with 5 of retrospective observational design and 17 case reports. There were 28 unique cases of breast cancer present and 9 of them were found after chest contouring mastectomy, with an average of 8.5 years’ time till diagnosis.

All 28 cases included patients that received cross sex hormone therapy prior to diagnosis with an average of 6.7 years between treatment and diagnosis. The ages of patients with breast cancer were between 35 years to 59 years old, with averages in the 40’s range.

Epidemiology of Breast Cancer in Trans Men

One study reported the population of transgender men in a Dutch cohort had a breast cancer incidence of 5.9 in 100,000 men. Additionally, another Dutch cohort had an incidence ratio of 0.2 for transgender men compared with cisgender women but 58.9 for transgender men to cisgender men.

In addition, transgender Dutch men had an earlier age of diagnosis of breast cancer, with an average age of 47 years vs 61 years for cisgender women. This was reflected in all 28 cases included in the review.

One study had the oldest cohort evaluated for breast cancer incidence with 1579 assigned female sex at birth and 25% of patients older than 65 years old.

"Detection of breast cancer in trans men at a younger age than cis women could be a result of age bias related to the rising incidence of gender dysphoria accompanied by a lack of long-term follow-up in an adequate number of trans men," the authors conjectured.

Breast Cancer Screening in Cisgender Women vs Transgender Men

Based on recommendations from the World Health Organization, all women aged 50 years to 69 years old should undergo biannual mammograms. Although, Swedish guidelines caution cisgender women to receive routine mammograms beginning at 40 years old and repeating every 18 months to 24 months until they reach 74 years old.

Patients who are classified as high risk, usually BRCA1/2 carriers, are offered MRI screening from age 25 to 55 years. Ultrasounds are suggested for patients who have at least a 20% increased risk with dense breast tissue and are less than 50 years old.

Guidelines for breast cancer screening in transgender men prior to chest contouring mastectomy are similar to the current suggestions for cisgender women, the authors noted; however, there is a lack of consistency in the existing recommendations for screening transgender men after chest contouring mastectomy. Some health care professionals suggest discussions between patients and physicians about screenings while others have advised annual chest and axillary exams, as others suggest mammograms every 2 years between ages 50 to 69.

Histopathologic Examination of Breast Tissue From Cisgender Women vs Transgender Men

Similar to chest contouring mastectomy for transgender men, reduction mammoplasty is a common surgery cisgender women undergo to decrease the amount of breast tissue, oftentimes due to physical discomfort or for cosmetic purposes. It is common for physicians to complete a routine histopathologic examination of excised breast tissue after reduction mammoplasty, regardless of the age of the patient. However, patients under the age of 40 typically weigh the costs versus benefits of histopathologic exams prior to committing to a decision.

There were several differing suggestions found in the literature about histopathology after reduction mammoplasty procedures. Some believed patients older than 35 years should have a gross examination of breast tissue by a pathologist, then a histopathologic examination of up to 7 breast sections or up to 6 sections for patients older than 50 years. Other recommendations for histopathologic exams included patients beginning at age 30 years and all patients that underwent reduction mammoplasty should receive an assessment.

The review did not find evidence of any existing guidelines for histopathologic examinations following chest contouring mastectomy for transgender men. There were some proposals suggested, including all excised breast tissue should undergo pathologic examination and recommendations of examinations of 4 tissue blocks per mastectomy. However, data showed no studies that had a confirmed practice as a clinical necessity.

Comparison and Applicability

Cisgender women who underwent reduction mammoplasty and transgender men who received chest contouring mastectomy have similarities and differences between them. Both groups have similar levels of variance in family history of breast cancer, ultimately affecting preoperative breast radiological or genetic screening. Additionally, both procedures require a negative family history of breast cancer to undergo breast remodeling. Based on these comparisons, guidelines created for reduction mammoplasty could reflect histopathologic examinations after chest contouring mastectomy in transgender men.

Some differences between reduction mammoplasty and chest contouring mastectomy include the administration of cross sex hormone treatment in many transgender male populations. There is no consensus as to whether cross sex hormone therapy can affect the risk of breast cancer development, making it possible for transgender men to not adhere to existing guidelines for breast cancer screening. It is also unclear if transgender men will follow "consistent self-examination of the breasts, given that an aversion toward female secondary sex characteristics is common in patients with [gender dysphoria]."

Surgical Considerations Regarding Breast Cancer Risk

While some physicians may assume chest contouring mastectomy procedures produce the same outcomes as prophylactic mastectomies, some studies have found not all patients that undergo chest contouring mastectomy remove all breast tissue, making it irrelevant in eliminating breast cancer. Although, some studies have found the reduction of breast tissue can be linked to a lower risk of breast cancer.

Cross Sex Hormone Therapy

Often, it is assumed transgender men have less risk of breast cancer following chest contouring mastectomy because of their small amount of breast tissue and low levels of estrogen. This hypothesis does not necessarily reign true because high levels of endogenous testosterone in cisgender women is a risk of breast cancer. For transgender men that are administered high doses of cross sex hormone therapy, testosterone serum levels are higher than those in cisgender men and women.

For cisgender women with high levels of testosterone, studies have found higher aromatase activity involved in estrogen production that leads to possible oncogenic pathways but the increased serum levels and the impact they have on breast cancer risk is unknown for the transgender male population.

Breast Cancer Screening Modalities for Transgender Men

While there are no reports of screening modalities for breast cancer in transgender men, guidance on screening in cisgender men can be effectively utilized. Following chest contouring mastectomy, mammography could show equal effectiveness in transgender men. However, some data showed complexity of mammography interpretation after reduction mammoplasty, suggesting a secondary modality for screenings after reduction mammoplasty and chest contouring mastectomy. There are some histopathologic studies that found an increased ratio of fibrous stroma in transgender men after receiving cross sex hormone therapy, making it unclear how this affects breast tissue and screening performance before and after the procedure.

Screening-Related Harm

Over diagnosis was found to be a major contribution to screening-related harm, followed by damage from radiation treatment, incidence of false positives or negatives, potential morbidity or mortality, and the psychological impact of the diagnosis.

Risk Management

Due to limited research, risk management is crucial for breast cancer in transgender men. This includes pre-surgery risk assessment, considering mammograms for high-risk patients over 40 years, and physician/patient education regarding residual breast tissue and follow-up. Until transgender-specific guidelines exist, adapting those for cisgender women is recommended.

Conclusions on Screening in Transgender Men

The review included studies that were all considered low to very low quality and were unable to conclude any epidemiology of breast cancer in transgender men. There were limited cases on the scope of breast cancer in transgender men. Prior to study initiation, the study protocol was never published and could potentially introduce bias. Based on the review findings, it is suggested histopathologic exams follow chest contouring mastectomy in transgender men as a breast cancer screening prevention method but if this is not feasible, guidelines for cisgendered women should be followed.

References

1. Edvin Wahlström, Audisio RA, Selvaggi G. Aspects to consider regarding breast cancer risk in trans men: A systematic review and risk management approach. PLOS ONE. 2024;19(3):e0299333-e0299333. doi:10.1371/journal.pone.0299333

2. Masculinizing chest reconstruction (“top surgery”). Trans Care UCSF. Accessed June 20, 2024. https://transcare.ucsf.edu/masculinizing-chest-reconstruction-top-surgery

3. Top/chest contouring surgery. Cooper Health. Accessed June 20, 2024. https://www.cooperhealth.org/services/top-chest-contouring-surgery#:~:text=The%20procedure%20allows%20transgender%20men

4. Turban J. What is gender dysphoria?. American Psychiatric Association.August 2022. Accessed June 20, 2024. https://www.psychiatry.org/patients-families/gender-dysphoria/what-is-gender-dysphoria

5. Zaliznyak M, Bresee C, Garcia MM. Age at first experience of gender gysphoria among transgender adults seeking gender-affirming surgery. JAMA Netw Open. 2020;3(3):e201236. doi:10.1001/jamanetworkopen.2020.1236

6. Lei S, Zheng R, Zhang S, et al. Global patterns of breast cancer incidence and mortality: A population-based cancer registry data analysis from 2000 to 2020. Cancer Commun (Lond). 2021;41(11):1183-1194. doi:10.1002/cac2.12207